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Electronics => Projects, Designs, and Technical Stuff => Topic started by: GK on March 12, 2017, 05:07:11 pm

Title: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 12, 2017, 05:07:11 pm
EDIT: (4/4/17). For a complete set of schematics and equiv. diagrams collated into a single PDF document click: http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf (http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf)
--------------------


This weekend I started soldering discrete components together like a man possessed and this is what came of it.

There are four switchable modes of play:

1) Machine against machine
2) Player 1 against machine
3) Player 2 against machine
3) Player 1 against player 2

Player one controls the paddle on the left and player 2 the paddle in the right. The hand controllers are just zippy boxes each with a pot and knob, though the player 1 controller sports a "serve ball" momentary push-button. A match/game starts on the pressing of this button.

In the attached video (mode 2) I am playing against the machine, which is controlling the paddle on the right. The velocity of the ball begins at a slow and easy rate but in order to ensure a match cannot last forever, from the start of play the ball velocity linearly ramps up. It will continue for as long as the player(s) can keep up with it.
If either player misses the ball the match ends with a 150 Hz bzzztttt and the ball is automatically returned to the center of the court where it remains stationary until player one presses the "serve ball" button to commence a new match.

The sound in the youtube video is a bit quiet and you have to crank the volume up a bit to hear all of the sound effects.  :)

https://www.youtube.com/watch?v=f7A5J30cqRk (https://www.youtube.com/watch?v=f7A5J30cqRk)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Elf on March 12, 2017, 05:17:48 pm
Hah, they have something exactly like that at the Living Computer Museum (http://www.livingcomputers.org/) (Seattle, WA).

Very nice!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 12, 2017, 05:19:25 pm
The circuity is 100% discrete and built entirely "dead bug". With the exception of a 2N2219A/2N2905A complementary pair for driving the speaker, it's all BC550C and BC560C, a bunch of 2N5484 FETs for analogue multiplexing, lots of 1N4148 and a few zeners.  There is close to 200 transistors, I think; I haven't counted them yet.

I'm currently drawing up all of the schematic diagrams for presentation and collating them into a single multiple-page PDF document. I'm only currently half way through; some teasers attached. It's getting onto 4am now' I'm going to bed.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298783;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298785;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298787;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298789;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 12, 2017, 05:21:34 pm
 :clap: I see you took my recommendation from you telefunken bouncing ball post a month or 2 back.
Great job.  I like the fact that you ball is round and you have a center court net while other oscilloscope pong games are nothing more than a dot for a ball with 2 paddles.

 :-+ Wow, that would drive me nuts trying to wire today.  In my high-school years, if I would have a scope at the time instead of an Atari 800, I would have attempted something like that for the challenge.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Howardlong on March 12, 2017, 05:21:53 pm
Maximum respect!  :-+ :-+ :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 12, 2017, 05:23:51 pm
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299064;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298793;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 12, 2017, 05:25:41 pm
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298993;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298797;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: sentry7 on March 12, 2017, 05:28:57 pm
Cleanest point-to-point execution for a scope pong game I think I will see for a while....it's definitely a 10. Kudos to you. William Higginbotham would have been proud. The video game industry in all of it's awesomeness started with this circuit.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Rolo on March 12, 2017, 05:38:26 pm
That is a piece of art. If you're done playing with it you can hang it on the wall. Well done !
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 12, 2017, 05:42:47 pm
I have one minor addition for the analog computer player which might not be to difficult to incorporate.  Instead of making the paddle track instantly the balls vertical location, add an inductor/cap/adjustable resistor (the inductor is to give the computer player a life-like wave motion instead of just speed limitation) delay to fudge up the positioning of it's response giving the player a chance to win when the ball gets really fast.  Having a difficulty skill setting for the analog computer by setting how fast and accurate it's paddle responds...

Once again,  :-+ an amazing work.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: sentry7 on March 12, 2017, 05:55:02 pm
I've studied for years on how back in the late 60s - early 70s, getting this circuit from the scope to TV was the Mt. Everest of the budding video game industry.

Allan Alcorn who was a young upstart at Atari and designed the original PONG in '72 talked about how Nolan Bushnell (then CEO) lied to him and told him that they had a contract with General Electric. He tricked him into getting a working prototype in less than a week! After that, Bushnell decided he wanted sound too!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 12, 2017, 06:20:07 pm
:clap: I see you took my recommendation from you telefunken bouncing ball post a month or 2 back.


Kinda. I was reading up on the original arcade video game ( https://en.wikipedia.org/wiki/Pong ) and found the schematics. That was all done in TTL. My first idea was to recreate the original TTL (logically) in discrete, but that would be more than I can spare the time for right now. So, drawing from my previous bouncing ball stuff I decided to do it analogue (well mostly) for display on a 'scope rather than a TV. The circuity here is entirely my own, BTW.


Quote
Great job.  I like the fact that you ball is round and you have a center court net while other oscilloscope pong games are nothing more than a dot for a ball with 2 paddles.

 :-+ Wow, that would drive me nuts trying to wire today.  In my high-school years, if I would have a scope at the time instead of an Atari 800, I would have attempted something like that for the challenge.


Thanks. My initial plan didn't include the court divider, but that was actually added as a circuit simplification when I finalised the display control logic. Instead of having a counter that goes 0-1-2-0-1-2, decoded to reset on 3, to display paddle, paddle, ball, I added a fourth object (the court divider) so that my counter could be simplified to a 2-bit ripple.

Now I really have to get to bed, the sun is going to start rising soon!  :)

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: DaJMasta on March 12, 2017, 07:17:35 pm
Very cool, I can't for the life of me figure out why you'd want to do that dead bug style, though.  All those flying leads just make me think I'd drop a screwdriver on it or something and just be out of luck.  :-\


Anyways, I know polyester caps in an integrator is good form and all, but is that actually required for this application?  Is there enough fluctuation in other cap technologies for visible issues?



Still, very nice execution and great schematics - I think more than a few other people would want to build up this design.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: 2N3055 on March 12, 2017, 10:00:56 pm
Respect!!!  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: ChristofferB on March 13, 2017, 12:58:28 am
Amazing manhattan-style craftsmanship! You must have the patience of a saint!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on March 13, 2017, 01:07:38 am
Thanks for sharing another of your neat projects with us GK.  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mmagin on March 13, 2017, 03:02:17 am
You built this in a single weekend?  I wish I was so insanely productive.  Wow.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 03:43:08 am
Yes, but I did all of the design work (drafted mostly in LTspice) the past week. Didn't get much else done this weekend though! ;D Slowly working through the re-drawn schematics........

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298976;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298978;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298982;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=298987;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 04:12:47 am
EDIT: Just corrected a small omission on the Ball Horizontal Movement circuit. Hmm............ think I'll put my pen and paper down for a bit now, log off and go off and eat something......
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 13, 2017, 04:56:09 am
Holy crap! That's amazing!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: boffin on March 13, 2017, 06:14:58 am
anyone else have the sudden urge to bow multiple times while chanting "we're not worthy" ?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 13, 2017, 06:28:30 am
Now that is a amazing project right there! :-+

I know this can be done with one MCU and some resistors but it would not be anywhere near as cool. There is not even any opamps in there!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: JPortici on March 13, 2017, 06:51:34 am
Sir, you are insane.

*takes a bow*
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 13, 2017, 07:25:11 am
It's amazing what can be achieved, with a modest pile of discrete transistors, some passives and a blank (copper) piece of PCB. I'm amazed (as well as at the whole project/game) at the quality/accuracy of the sound effects, the quality of the nicely sized round ball and the multi-mode capabilities, including a man vs analogue computer mode.
The picture quality is so smooth and stable, despite the fact it is analogue and made in a way which would worry me (short circuits etc).

If I was told about such a project, I would not have expected it to be analogue, have no integrated circuits, be made without a PCB, be so (relatively) neatly constructed or work so well and with such quality in measurable ways.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 07:37:06 am
There is not even any opamps in there!


I count 9 op-amps!

;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 07:42:07 am
Another schematic diagram hot off the press. All that is left to draw now is the multiplexer amplifier pair that finally combines everything together for the vertical and horizontal deflection signals. Oh, that and the +/-14.3V power supply, which I haven't actually built yet as at the moment the unit is being powered from my bench supply. The power supply will be a very simple affair: 15V Zener diodes biasing series pass emitter-followers.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299012;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 08:42:08 am
Finally, the semiconductor tally (this includes the as yet un-built power supply):

BJTs - 184
JFETs - 11
Diodes (Si) - 130
Diodes (Zener) - 5
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 13, 2017, 08:50:20 am
Finally, the semiconductor tally (this includes the as yet un-built power supply):

BJTs - 184
JFETs - 11
Diodes (Si) - 130
Diodes (Zener) - 5

I can't seem to quickly come up with a more exciting/amazing project, to make with those 330 discrete semiconductors.  ;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 01:02:44 pm
The final schematic diagrams. Phew!

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299052;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299054;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 01:07:15 pm
I can't seem to quickly come up with a more exciting/amazing project, to make with those 330 discrete semiconductors.  ;D


Well I've now posted up the full schematic, so you can start compiling your BOM. If you want I can post a full resolution photo for layout assistance  ;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 13, 2017, 02:22:44 pm
I have one minor addition for the analog computer player which might not be to difficult to incorporate.  Instead of making the paddle track instantly the balls vertical location, add an inductor/cap/adjustable resistor (the inductor is to give the computer player a life-like wave motion instead of just speed limitation) delay to fudge up the positioning of it's response giving the player a chance to win when the ball gets really fast.  Having a difficulty skill setting for the analog computer by setting how fast and accurate it's paddle responds...

Once again,  :-+ an amazing work.


I did have almost that exact idea - to put an RC time constant between "Ball-Y" and the machine-driven paddle-Y. The idea is that the speed of the ball would eventually become too fast for the machine-driven paddle to catch it; if you could keep up for that long you'd invariably win. That would require buffering the RC after "Ball-Y" from the respective paddle-Y input though, as the paddle-Y inputs are 10k||39k; a value of R for a practical value of C would otherwise attenuate the signal. Another idea was to have selectable paddle sizes and an additional pair of window comparators in the "Ball-Paddle collision detection" circuit so that the ball could be made to deflect at a different angle if it hits the outer edges of a paddle rather than the middle. The scope for building upon the basic concept is endless, but one has to draw the line somewhere!
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 13, 2017, 02:46:40 pm
Nice. Anyone who wants to draw the schematics in KiCad? Otherwise I could try it, good learning project, because I'm switching from Eagle. The hierarchical feature (missing in Eagle before V7) might be useful for this complexity.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 13, 2017, 06:32:42 pm
There is not even any opamps in there!


I count 9 op-amps!

;D

Well okay there are discrete opamp cirucits but i meant that no opamp chips are in the design. I know if i ever went to do something like this it would end up a heap of quad opamps stringed together with passives. But that would not look as impressive for sure.

If you ever put this piece of art in to a case make sure the case has a window to let you see its guts. Perhaps also add in a few LEDs on interesting signals (Like ball movement directions and sound)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 13, 2017, 06:53:10 pm
I can't seem to quickly come up with a more exciting/amazing project, to make with those 330 discrete semiconductors.  ;D


Well I've now posted up the full schematic, so you can start compiling your BOM. If you want I can post a full resolution photo for layout assistance  ;D

If enthusiasts end up laying this out as an "open source" type of project, onto a PCB. I imagine it will be a highly tempting fun project, for many on this forum.
The parts cost is probably low, with no hard to get components.

But as regards that style of construction, although I admire your work and relative neatness in making it that way. I would probably find it too frustrating, to attempt to make it that way.

If you weren't joking, full/high resolution pictures would be very nice to look at anyway. Even if that method of construction is not really my cup of tea. But I'd seriously consider it for small, very high frequency/performance projects, as a possible option.
E.g. When making a small/simple, but super fast transition avalanche pulse generator.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: nkeck72 on March 13, 2017, 08:04:55 pm
Don't sneeze or one of the several trimmers might get knocked off cal! :-/O


Seriously though, this thing is amazing. That seems like a lot of work to get running. Kudos to you!
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 13, 2017, 11:34:58 pm
Nice. Anyone who wants to draw the schematics in KiCad? Otherwise I could try it, good learning project, because I'm switching from Eagle. The hierarchical feature (missing in Eagle before V7) might be useful for this complexity.


I was actually thinking about laying this out in DipTrace as a fun project. I'd of course open source the boards, that is assuming GK doesn't mind. :)

Edit: Thinking about this some more, it could be converted to a PCB pretty easily, but the transistors would need to be changed to something a bit more easily available. Looking at the ratings of the BC550, I imagine they could be swapped out with 2N3904's (or MMBT3904's for a SMD kit) without issue, yeah?

Edit 2: Maybe not, the BC550 has an hFE of 110-800 while the 3904 is 100-300. Hmm, no matter, I'm sure I could find a cheaper, well stocked replacement.

Edit 3: Hmm, BC850/860C would do nicely for a SMT design. The fT is a bit slower, but I think that would be alright here. Around $0.06 in quantity.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 14, 2017, 12:10:34 am
I would totally build one of these if there was a reasonably priced board available. Because if there's one thing I need it's more projects  ;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 14, 2017, 12:13:35 am
Hmm, BC550C/BC560C are readily available from all the major distributors:

http://www.digikey.com.au/products/en?keywords=bc550c (http://www.digikey.com.au/products/en?keywords=bc550c)
http://www.digikey.com.au/products/en?keywords=bc560c (http://www.digikey.com.au/products/en?keywords=bc560c)

The SMD (sot-23) versions are BC850C and BC860C, also readily available:

http://www.digikey.com.au/products/en?keywords=bc850c (http://www.digikey.com.au/products/en?keywords=bc850c)
http://www.digikey.com.au/products/en?keywords=bc860c (http://www.digikey.com.au/products/en?keywords=bc860c)


Note that if doing an all-SMD copy the power dissipation of many parts will have to be checked. 
 

The to-92 2N5484 FET is obsolete, but the sot-23 equivalent (MMBF5484CT) is active and readily available:

http://www.digikey.com.au/product-detail/en/fairchild-on-semiconductor/MMBF5484/MMBF5484CT-ND/3042817 (http://www.digikey.com.au/product-detail/en/fairchild-on-semiconductor/MMBF5484/MMBF5484CT-ND/3042817)


Any JFET substitute needs to have a max. Vgs-off spec comfortably under -9V and preferably not an order of magnitude greater junction capacitance than the 2N5484. The latter in particular needs to be watched in this application because the JFET capacitance is hanging on the sensitive virtual earth node of discrete op-amps. Some ultra/very low Rds-on "switching" JFET types can have very high junction capacitances, so be careful.


I think it would be great for anyone to commit to an open-source duplication of the design; just give credit to the origin please!
 
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 14, 2017, 12:20:13 am
Hmm, BC550C/BC560C are readily available from all the major distributors:

http://www.digikey.com.au/products/en?keywords=bc550c (http://www.digikey.com.au/products/en?keywords=bc550c)
http://www.digikey.com.au/products/en?keywords=bc560c (http://www.digikey.com.au/products/en?keywords=bc560c)

The SMD (sot-23) versions are BC850C and BC860C, also readily available:

http://www.digikey.com.au/products/en?keywords=bc850c (http://www.digikey.com.au/products/en?keywords=bc850c)
http://www.digikey.com.au/products/en?keywords=bc860c (http://www.digikey.com.au/products/en?keywords=bc860c)


Note that if doing an all-SMD copy the power dissipation of many parts will have to be checked. 
 

The to-92 2N5484 FET is obsolete, but the sot-23 equivalent (MMBF5484CT) is active and readily available:

http://www.digikey.com.au/product-detail/en/fairchild-on-semiconductor/MMBF5484/MMBF5484CT-ND/3042817 (http://www.digikey.com.au/product-detail/en/fairchild-on-semiconductor/MMBF5484/MMBF5484CT-ND/3042817)


Any JFET substitute needs to have max. Vgs off spec comfortably under -10V and preferably not an order of magnitude greater junction capacitances than the 2N5484. The latter in particular needs to be watched in this application because the JFET capacitance is hanging on the sensitive virtual earth node of discrete op-amps. Some ultra/very low Rds-on "switching"-type JFET types can have very high junction capacitances, so be careful.


I think it would be great for anyone would commit to an open-source duplication of the design; just give credit to the origin!

Yeah, I saw the BC550C on Digi-Key, but it only said 800 in stock ~30 minutes ago, and they're $0.3/ea in small quantities. Whereas the BC850's are $0.1 and have 50k+ in stock.

My thought would be to do a mixed technology board. Use SMT transistors and TH caps, diodes, etc.

Perhaps release it as a kit, with the SMD stuff pre-soldered and let them stuff all the TH stuff by hand?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 14, 2017, 12:36:42 am
Why have the SMT parts already soldered? That always bugs me, just let me build the whole kit. If someone is going to have a use for something as esoteric as analog oscilloscope Pong, they ought to be able to hand solder SMT parts. We're not talking 672 pin BGAs here.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 14, 2017, 12:37:57 am
Amazing work, GK! That's a lot of point-to-point-to-point-to-point-...

Tim, looking forward to seeing your kit of it. Perhaps have the option to assemble everything, including SMT parts.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 14, 2017, 01:13:03 am
Any JFET substitute needs to have max. Vgs-off spec comfortably under -10V and preferably not an order of magnitude greater junction capacitance than the 2N5484. The latter in particular needs to be watched in this application because the JFET capacitance is hanging on the sensitive virtual earth node of discrete op-amps. Some ultra/very low Rds-on "switching" JFET types can have very high junction capacitances, so be careful.

I think it should be all through-hole, looks more authentic :) Would this JFET work? http://www.digikey.de/short/32rhf3 (http://www.digikey.de/short/32rhf3)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on March 14, 2017, 01:25:55 am
I think it should be all through-hole, looks more authentic :)

+1 , and also sort of 70s style pcb layout.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 14, 2017, 02:12:21 am
I think it should be all through-hole, looks more authentic :)

+1 , and also sort of 70s style pcb layout.

Right, with these squiggly traces:

(http://i56.tinypic.com/29p2he8.jpg)

But with two layers I could do it without bodge wires ;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 14, 2017, 04:00:00 am
Yes, squiggly traces are imperative for the vintage look.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 14, 2017, 06:18:26 am
Well you sure wouldn't want to make one of those in Altium. Those curve trace tools it has are better at frustrating you than actual drawing the right kind of curvy trace that you want.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 14, 2017, 08:14:40 am
Any JFET substitute needs to have max. Vgs-off spec comfortably under -10V and preferably not an order of magnitude greater junction capacitance than the 2N5484. The latter in particular needs to be watched in this application because the JFET capacitance is hanging on the sensitive virtual earth node of discrete op-amps. Some ultra/very low Rds-on "switching" JFET types can have very high junction capacitances, so be careful.

I think it should be all through-hole, looks more authentic :) Would this JFET work? http://www.digikey.de/short/32rhf3 (http://www.digikey.de/short/32rhf3)


That JFET looks fine. The transconductance is about the same as the '5484. Vgs-off max. is higher but still within limits. Rds-on might even be lower than the '5484.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 14, 2017, 08:46:22 am
Just a quick note on 'scope compatibility for anyone getting excited over building the design. Your analogue 'scope needs to have a suitable Z "blanking" or "intensity modulation" input.

The Z-input  waveform is a 1200Hz squarewave which cuts the 'scope's CRT beam off when high. This squarewave is phased so that switching of the analog multiplexer occurs in the middle of the high period. Blanking the beam ensures that switching glitches/artifacts aren't visible on the display and nor is the trace as it jumps from one drawn object (which goes: ball, court divider, paddle1, paddle2, ball, court divider, ........ and so on) to the next. The blanking waveform generated is about 14V peak, which is adequate for total beam cut-off for most oscilloscope Z-inputs.

From one of my LTspice simulations of the design, here is what the typical X,Y,Z waveforms which scribe the display look like:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299214;image)



Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 14, 2017, 08:49:34 am
Well you sure wouldn't want to make one of those in Altium. Those curve trace tools it has are better at frustrating you than actual drawing the right kind of curvy trace that you want.
`

Arrrrg, now you tell me, after a decade ago I went through hell making nice PCBs with swiggly traces in Protel99, and cleaning up after all it's bugs...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 14, 2017, 08:53:52 am
Just a quick note on 'scope compatibility for anyone getting excited over building the design. Your analogue 'scope needs to have a suitable Z "blanking" or "intensity modulation" input.

The Z-input  waveform is a 1200Hz square wave which cuts the 'scope's CRT beam off when high. This square wave is phased so that switching of the analog multiplexer occurs in the middle of the high period. Blanking the beam ensures that switching glitches/artifacts aren't visible on the display and nor is the trace as it jumps from one drawn object (which goes ball,court divider,paddle1,paddle2,ball, court divider,........ and so on) to the next. The blanking waveform generated is about 14V peak, which is adequate for total beam cut-off for most oscilloscope Z-inputs.

From one of my LTspice simulations of the design, here is what the typical X,Y,Z waveforms which scribe the display look like:



For those making a public source design, I would recommend making a second inverted 'Z' in case their scope or x/y display blanks on a low Z signal input instead of a high.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 14, 2017, 12:56:32 pm
For those making a public source design, I would recommend making a second inverted 'Z' in case their scope or x/y display blanks on a low Z signal input instead of a high.


I wonder if there are many 'scopes that operate that way of if there are some out there which actually require a negative polarity pulse to blank their beams? Perhaps it would be useful if members out there could consult their manuals or just hook a function generator up to the Z input of their analogue oscilloscopes, so some kind of general list of requirements can be drawn up? 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 14, 2017, 12:58:40 pm
OK, when you (anyone) eventually gets a copy of this machine up and running , you're going to have to adjust a few trimmer potentiometers. This attached diagram tells you all you need to know.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299233;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 14, 2017, 01:54:49 pm
For those making a public source design, I would recommend making a second inverted 'Z' in case their scope or x/y display blanks on a low Z signal input instead of a high.


I wonder if there are many 'scopes that operate that way of if there are some out there which actually require a negative polarity pulse to blank their beams? Perhaps it would be useful if members out there could consult their manuals or just hook a function generator up to the Z input of their analogue oscilloscopes, so some kind of general list of requirements can be drawn up?

My DSO-X 3012A digital scope has a 1.4 V blanking threshold, using the external trigger input at the back. If the voltage is higher, it blanks the trace in X/Y mode. But I guess it doesn't look nice on these modern digital scopes. I have a Voltcraft AO 610 analog scope, too, but unfortunately it doesn't have a blanking input. But from your LTspice waveforms it looks like it might still work, but with thin traces between the graphical elements.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 14, 2017, 02:21:40 pm
While searching for a nice scope with Z input, I found this:

http://www.digimessinstruments.co.uk/manuals/german/mmoseriesengandger.pdf (http://www.digimessinstruments.co.uk/manuals/german/mmoseriesengandger.pdf)

On page 20 it says: "The Z axis terminal on the rear of the unit allows adjustment of the intensity using an external signal. The characteristics are positive level for improved stability and negative level for increased intensity of the waveform.". I really don't know what they mean with "stability" (and the German translation at the end of the document makes no sense at all), but sounds like it blanks on positive voltages, too. We'll see, I can get it for EUR 49 from eBay, if no one other bids :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 14, 2017, 07:57:56 pm
Why have the SMT parts already soldered? That always bugs me, just let me build the whole kit. If someone is going to have a use for something as esoteric as analog oscilloscope Pong, they ought to be able to hand solder SMT parts. We're not talking 672 pin BGAs here.

It's a lot of SOT-23 parts to solder by hand, but personally I wouldn't mind doing them all by hand, soldering is sort of like meditation for me. I guess other people are the same?

Yes, squiggly traces are imperative for the vintage look.

Oh yeah, I already started laying out the first schematic last night as a test. I'm going with curved traces for a hand taped out look. It's driving my pseudo-OCD over the edge a bit, since things aren't perfectly aligned like I'm used to, but I'll adapt!

I think it should be all through-hole, looks more authentic :)

+1 , and also sort of 70s style pcb layout.

I may have a good source on the TH transistors, stay tuned!

Amazing work, GK! That's a lot of point-to-point-to-point-to-point-...

Tim, looking forward to seeing your kit of it. Perhaps have the option to assemble everything, including SMT parts.


Yeah, after seeing the response here, I think that's the way to go!

Any JFET substitute needs to have max. Vgs-off spec comfortably under -10V and preferably not an order of magnitude greater junction capacitance than the 2N5484. The latter in particular needs to be watched in this application because the JFET capacitance is hanging on the sensitive virtual earth node of discrete op-amps. Some ultra/very low Rds-on "switching" JFET types can have very high junction capacitances, so be careful.

I think it should be all through-hole, looks more authentic :) Would this JFET work? http://www.digikey.de/short/32rhf3 (http://www.digikey.de/short/32rhf3)

Keep in mind that, in a lot of cases, TH parts are considerably more expensive.

I may have come up with a way to allow SMT *or* TH transistors to be used on the same board, without adversely affecting the layout. The idea being the board could be offered as a kit with all the parts (using SMT transistors) *or* you could maybe buy just a board (or have one made from the gerbers) and buy the TH parts yourself. That might suit everyone.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 14, 2017, 08:11:28 pm
OK, when you (anyone) eventually gets a copy of this machine up and running , you're going to have to adjust a few trimmer potentiometers. This attached diagram tells you all you need to know.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299233;image)

Hey GK, can I get high resolution copies of the schematics? The ones posted her get pixelated when I zoom in. The original scanned resolution would be super helpful!

You can email them (sysop AT timb DOT us) or send a Dropbox link or whatever. That would be super helpful!

(I tried PMing you, but you've got it turned off.)

Thanks!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 14, 2017, 08:29:46 pm
Yes, squiggly traces are imperative for the vintage look.
Oh yeah, I already started laying out the first schematic last night as a test. I'm going with curved traces for a hand taped out look. It's driving my pseudo-OCD over the edge a bit, since things aren't perfectly aligned like I'm used to, but I'll adapt!

Hang in there, Tim! :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 15, 2017, 11:14:47 am
My DSO-X 3012A digital scope has a 1.4 V blanking threshold, using the external trigger input at the back. If the voltage is higher, it blanks the trace in X/Y mode. But I guess it doesn't look nice on these modern digital scopes. I have a Voltcraft AO 610 analog scope, too, but unfortunately it doesn't have a blanking input. But from your LTspice waveforms it looks like it might still work, but with thin traces between the graphical elements.


I think this application is a good excuse to get another analogue oscilloscope ;D Here are screen photos with and without z-axis blanking, displayed on both my ancient Tek 422 and even ancienter Tek 545B.

Without blanking the beam artifacts aren't too bothersome so long as the intensity isn't turned up too high. Keep in mind though that these photographs make the situation without blanking appear significantly less bad than it really is. The camera seems to be a lot more sensitive to the colour of the light emitted by the CRT phosphor than is the human eye. In the photos the display looks really bright and a bit plumed, but in reality I had the intensity turned down as low as is acceptable for comfortable viewing.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299461;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299463;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 15, 2017, 11:37:09 am
Oh, one last schematic diagram - the power supply. It's getting really technical now! 2N3055/MJ2955 for that '70s look. Other benefits are that the cans can dissipate the required power without heatsinking and the transistors will easily survive a momentary short on the output if you slip with your DMM or scope probes (unless you use a 300VA toroid or something for the power transformer).

Measured supply rail current on the positive rail with the audio volume at a comfortable level averages about 220mA and the negative rail averages about 120mA. Probably being a bit pedantic here, but please ignore the current readings on my crappy Powertech bench supply visible in the posted video. They aren't accurate a all.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=299466;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 15, 2017, 11:47:28 am
Hey GK, can I get high resolution copies of the schematics? The ones posted her get pixelated when I zoom in. The original scanned resolution would be super helpful!

You can email them (sysop AT timb DOT us) or send a Dropbox link or whatever. That would be super helpful!

(I tried PMing you, but you've got it turned off.)

Thanks!


OK, I've up-loaded full-res PDFs here:

http://www.glensstuff.com/pong/ (http://www.glensstuff.com/pong/)

BTW, w.r.t. kit-setting; if the intent is just a service to members here in the same spirit that I shared the design in the first place then I am fine with that; but definitely iffy if the broader intent is commercialisation outside of the forum community.

One you've drafted the schematics you can send them to me for double checking if you want. I can download either the free or the 30-day trial version of Diptrace.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: ajb on March 15, 2017, 05:04:02 pm
This could make a really phenomenal instructional kit, if you were amenable and if someone were willing to put in the work to create the additional materials.  If the circuit were broken up into discrete sections that could be built up and tested one at a time, for each section you could have:

-  a brief intro ("we want to draw this shape, that means we need to generate these sorts of signals")
- the relevant schematic and a description of how it works
- assembly instructions
- then testing/adjustment/troubleshooting instructions with some example waveforms, and maybe some more in-depth discussion of the circuit operation with implementation advice.

It would be a lot of work, but it would be a great opportunity to learn about so many analog building blocks.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 15, 2017, 05:08:40 pm
Hey GK, can I get high resolution copies of the schematics? The ones posted her get pixelated when I zoom in. The original scanned resolution would be super helpful!

You can email them (sysop AT timb DOT us) or send a Dropbox link or whatever. That would be super helpful!

(I tried PMing you, but you've got it turned off.)

Thanks!


OK, I've up-loaded full-res PDFs here:

http://www.glensstuff.com/pong/ (http://www.glensstuff.com/pong/)

BTW, w.r.t. kit-setting; if the intent is just a service to members here in the same spirit that I shared the design in the first place then I am fine with that; but definitely iffy if the broader intent is commercialisation outside of the forum community.

One you've drafted the schematics you can send them to me for double checking if you want. I can download either the free or the 30-day trial version of Diptrace.
 

Thanks! Once I get back to my computer tonight I'll grab those. That'll make it a lot easier to convert. I can also send you the DipTrace schematics in PDF form if you don't want to download DipTrace. (I've got Ghostscript setup as a PDF printer.)

My intent was just to share it with the forum community. I figure once the boards are done, I'd see how many other people want them, order a batch and then order enough parts to do them all. The parts will obviously be a lot cheaper if ordered in larger quantities. (If just five people are interested in kits the price can be almost cut in half!)

I'm doing this because I think it's an awesome project and I want one myself! It's also a bit of a challenge to do layout for. I'm not looking to commercialize it or to make any money off it; any parts kits would be sold to forum members at cost.

I did plan on releasing the Gerbers and a full BOM though, assuming you're alright with that.

I captured and laid out a small section less night in both SMD and TH varieties, to see how much space each took. Using SOT-23 transistors and 1206 resistors/capacitors takes up about 1/3 less board space than TH parts, is easier to layout and may be cheaper (and easier to get) to boot, on the other hand, TH does look a lot more authentic, so I'm a bit torn which direction to go.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 15, 2017, 06:32:28 pm
That's a tough one, Tim. THT does maintain the right look and feel. However, an SMT board 1/3 the size is also appealing and 1206 is reasonable.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 15, 2017, 07:39:00 pm
How about both? Do a layout for TH and do another layout for SMT. My vote would be 0603, but I have loads of passives in those sizes.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 15, 2017, 07:50:19 pm
How about both? Do a layout for TH and do another layout for SMT. My vote would be 0603, but I have loads of passives in those sizes.

O805, or 1206, you want clean clearance for traces to go under the SMD part for those of use who might do home made copper clad etchings without the fine resolution of a pro-made PCB or the right SMD assembly tools.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 16, 2017, 01:32:51 am
Thanks! Once I get back to my computer tonight I'll grab those. That'll make it a lot easier to convert. I can also send you the DipTrace schematics in PDF form if you don't want to download DipTrace. (I've got Ghostscript setup as a PDF printer.)

My intent was just to share it with the forum community. I figure once the boards are done, I'd see how many other people want them, order a batch and then order enough parts to do them all. The parts will obviously be a lot cheaper if ordered in larger quantities. (If just five people are interested in kits the price can be almost cut in half!)

I'm doing this because I think it's an awesome project and I want one myself! It's also a bit of a challenge to do layout for. I'm not looking to commercialize it or to make any money off it; any parts kits would be sold to forum members at cost.

I did plan on releasing the Gerbers and a full BOM though, assuming you're alright with that.


That's all cool. I don't care if you actually make a few trivial bucks here; it's just about fair use of IP, not any anti-capitalist ideology.

The last time I did something like this I sold off the boards above cost (though not by much); not as a money making endeavour as it hardly compensated my time invested (post office trips, filling out customs forms, blah, blah) but just to ensure that after sundry expenses (variations in postage costs to different countries, fuel for 6.3L car engine, etc) the endeavour wouldn't see me in the red.

Heck, if it means enabling half a dozen other members here to get duplicate builds up and running I think you could fairly recoup the cost of your own build; it would only be a knob that would get enviously or narky at you for that.
       
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on March 16, 2017, 02:32:42 am
Tim, thanks for the work, count me in for THT board, I can source the components my self.

Hope I can still source TO-18 style transistors.  >:D Also planning to find the 70s or 80s style enclosure, the step down transformer too.

Btw, the reason I prefer THT is the excitement and the fun during the assembling, at least for me, cause once finished and working, realistically I won't be playing this on my scope everydays, only once in a while or probably bring it and brag it among friends.  >:D

Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 16, 2017, 07:39:25 am
That's a tough one, Tim. THT does maintain the right look and feel. However, an SMT board 1/3 the size is also appealing and 1206 is reasonable.

Exactly.

Here's the components for just the "Velocity Integrator" portion of the circuit in SMD and TH:

(http://timb.us/images/Scope_Pong_1.png)

(http://timb.us/images/Scope_Pong_2.png)

(http://timb.us/images/Scope_Pong_3.png)

As you can see, component area is significantly less with he surface mount parts (maybe even less considering some could be placed on the bottom of the board as well). Obviously I could save space by doing the resistors in a vertical format, though personally I'm not a fan of that.

Based on parts count and some quick layout tests, I think the surface mount design would easily fit on a couple of 100x100mm boards that would be stacked. (Ideally I'd like to stay at that size since they can be inexpensively fabricated. Though I do have access to a US fab that will do 200x200mm boards on the cheap.)

The more I think about this, the more I like the esthetics of a TH layout, but man things would be easier with a SMD design!

Tim, thanks for the work, count me in for THT board, I can source the components my self.

Hope I can still source TO-18 style transistors.  >:D Also planning to find the 70s or 80s style enclosure, the step down transformer too.

Btw, the reason I prefer THT is the excitement and the fun during the assembling, at least for me, cause once finished and working, realistically I won't be playing this on my scope everydays, only once in a while or probably bring it and brag it among friends.  >:D

For what it's worth, if I did an SMT board it could still all be hand soldered as I'd use large pads to make it easy. 1206 and SOT-23 can all be hand soldered with nothing but an iron, some flux and semi-fine solder.

In the end, even if I go TH at least a few parts would possibly still need to be SMT, like the JFETs which are obsolete in TO-92. (Unless I get a suitable replacement.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 16, 2017, 10:47:21 am
Timb, just in case, pay attention to via hole size and placement.  If you were to publish the gerbers for those who want to etch a 2 layer PCB, remember that they might be soldering wires from top to bottom for their vias and some through hole components.

Remember, we may be drilling the holes with a cheap dremel drill press...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 16, 2017, 05:51:20 pm
Timb, just in case, pay attention to via hole size and placement.  If you were to publish the gerbers for those who want to etch a 2 layer PCB, remember that they might be soldering wires from top to bottom for their vias and some through hole components.

Remember, we may be drilling the holes with a cheap dremel drill press...

Yeah, I thought about that! I've never home etched a complex double sided board before, what do you think is the smallest hole most people can reliably drill at home with a cheap drill press?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 16, 2017, 06:08:44 pm
The more I think about this, the more I like the esthetics of a TH layout, but man things would be easier with a SMD design!

It is more period appropriate to go TH.

I guess this means I'll have to fix my old analog scope. ::)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 16, 2017, 06:09:48 pm
I don't recall the size, but when I was etching double sided boards I used a drill that was just right for a close fit of a piece of stripped wire wrap wire that I used for the vias. My PCB drill is home made, wooden frame made of 2x4 lumber with a precision slide screwed to it. I found it worked much better than those cheap Dremel drill presses, lots fewer broken bits.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on March 16, 2017, 07:59:07 pm
Timb, just in case, pay attention to via hole size and placement.  If you were to publish the gerbers for those who want to etch a 2 layer PCB, remember that they might be soldering wires from top to bottom for their vias and some through hole components.

Remember, we may be drilling the holes with a cheap dremel drill press...

Yeah, I thought about that! I've never home etched a complex double sided board before, what do you think is the smallest hole most people can reliably drill at home with a cheap drill press?
0.6mm (24mil) no problem, never tried smaller.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 16, 2017, 07:59:55 pm
Yeah, I thought about that! I've never home etched a complex double sided board before, what do you think is the smallest hole most people can reliably drill at home with a cheap drill press?

I know this will sound big and ugly, but make the hole at least 12mil, the outer diameter 30mil.  The reason for the huge size is that when exposing home made boards, the top and bottom layer aren't always perfectly aligned and also when drilling though, a slight error in alignment can push off the copper pad on the other side if it is too thin.

The smallest I would go would be 10mil drill with 26 mil outer diameter, but, the above measurements would be better.
Careful with your transistor & passive component library, make sure they don't have smaller holes than what I've listed above.
For transistors, make sure the TO-92 has a the wide off-center center pin footprint spacing.  Since we might need to solder on the top and bottom, if the center pin is pushed back, soldering on the top of the PCB is much easier to do without shorting to the 2 adjacent pins.  Everything else should be easy to solder on both sides.


For the traces, I would mostly route 12mil, saving 10 mil when going under 1206 smd caps and resistors & sot23.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Fire Doger on March 16, 2017, 11:51:04 pm
WoW very nice!!!
At university we had an HP scope (I don't remember model) with tetris, scope games are awesome :P

Machine vs machine ends at some point or goes to max freq and still playing?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 17, 2017, 06:56:42 am
That would be the HP 54600 series scopes.

Its a digital scope so it was easy to add it in as a easter egg in the firmware.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 07:43:14 am
Yeah, I thought about that! I've never home etched a complex double sided board before, what do you think is the smallest hole most people can reliably drill at home with a cheap drill press?

I know this will sound big and ugly, but make the hole at least 12mil, the outer diameter 30mil.  The reason for the huge size is that when exposing home made boards, the top and bottom layer aren't always perfectly aligned and also when drilling though, a slight error in alignment can push off the copper pad on the other side if it is too thin.

The smallest I would go would be 10mil drill with 26 mil outer diameter, but, the above measurements would be better.
Careful with your transistor & passive component library, make sure they don't have smaller holes than what I've listed above.
For transistors, make sure the TO-92 has a the wide off-center center pin footprint spacing.  Since we might need to solder on the top and bottom, if the center pin is pushed back, soldering on the top of the PCB is much easier to do without shorting to the 2 adjacent pins.  Everything else should be easy to solder on both sides.


For the traces, I would mostly route 12mil, saving 10 mil when going under 1206 smd caps and resistors & sot23.

Thanks! Seems like good advice. When you talk about a wide off center trace for TO-92, do you mean like would be used for "Ammo Pack" style pre-formed leads? Or do you mean more TO-18 style where the center pin is vertically off center from the other pads?


So, I've decided to go mostly through hole, with some SMD. The JFETs will be SOT-23 due to availability and cost; tantalum caps will be SMD size D mainly due to cost (for example, a 100uF TH tantalum costs between $3 and $5 from Digi-Key, whereas a surface mount version would be less than $1).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 08:16:45 am
Thanks! Once I get back to my computer tonight I'll grab those. That'll make it a lot easier to convert. I can also send you the DipTrace schematics in PDF form if you don't want to download DipTrace. (I've got Ghostscript setup as a PDF printer.)

My intent was just to share it with the forum community. I figure once the boards are done, I'd see how many other people want them, order a batch and then order enough parts to do them all. The parts will obviously be a lot cheaper if ordered in larger quantities. (If just five people are interested in kits the price can be almost cut in half!)

I'm doing this because I think it's an awesome project and I want one myself! It's also a bit of a challenge to do layout for. I'm not looking to commercialize it or to make any money off it; any parts kits would be sold to forum members at cost.

I did plan on releasing the Gerbers and a full BOM though, assuming you're alright with that.


That's all cool. I don't care if you actually make a few trivial bucks here; it's just about fair use of IP, not any anti-capitalist ideology.

The last time I did something like this I sold off the boards above cost (though not by much); not as a money making endeavour as it hardly compensated my time invested (post office trips, filling out customs forms, blah, blah) but just to ensure that after sundry expenses (variations in postage costs to different countries, fuel for 6.3L car engine, etc) the endeavour wouldn't see me in the red.

Heck, if it means enabling half a dozen other members here to get duplicate builds up and running I think you could fairly recoup the cost of your own build; it would only be a knob that would get enviously or narky at you for that.
     

Oh yeah, totally. I'd planned on putting your name and a link to your site on the boards anyway, crediting you with the circuit design. You clearly put a ton of thought and effort into the design, so you deserve the credit.

So, a couple of questions I've come up with as I've been capturing the schematic:

Is there any particular reason the main rails are +-14.3V instead of, say, +-15V? I'm sure there must be some reason, so just curious.

Should a 20V rating be alright for the polarized caps? I can't see any place that the full 28.6V (between V+ and V-) would go across them.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 17, 2017, 08:46:52 am
+/-14.3V is just what the power supply delivers; will still operate fine on +/-15V rails. A 20V rating is adequate for the polarised caps.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 17, 2017, 08:48:51 am
WoW very nice!!!
At university we had an HP scope (I don't remember model) with tetris, scope games are awesome :P

Machine vs machine ends at some point or goes to max freq and still playing?


Hits full speed and just keeps going.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 08:50:48 am
+/-14.3V is just what the power supply delivers; will still operate fine on +/-15V rails. A 20V rating is adequate for the polarised caps.

Thanks! I just wanted to make sure I wasn't missing something. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 17, 2017, 12:07:20 pm
Thanks! Seems like good advice. When you talk about a wide off center trace for TO-92, do you mean like would be used for "Ammo Pack" style pre-formed leads? Or do you mean more TO-18 style where the center pin is vertically off center from the other pads?

I believe it's the TO-18 style, like this:
   O
O   O

This makes it easy for a hand soldering of a home made PCB where you can now soldier all 3 legs on the bottom and top without having your weller tip squeezing between 2 pins to solder the center pin.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 17, 2017, 12:14:03 pm
(for example, a 100uF TH tantalum costs between $3 and $5 from Digi-Key, whereas a surface mount version would be less than $1).

Aren't through-hole electrolytics the cheapest?
Question for GK, Should we be using electrolytics or tantalum caps in your circuit?
I know they slightly behave differently with ESR, voltage VS cap value and temperature.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on March 17, 2017, 12:15:45 pm
Agree with BriangHG, anyway they will be manually soldered one by one.

TO-18 triangle placed pins are easier to solder even with big soldering iron than single line of 3 pins TO-92s.

(http://www.dl7avf.info/charts/outlines/to18.gif)

(http://www.icinform.ru/sites/default/files/iibase/corp_b/238_b.png)

Besides, abit of bending the middle TO-92 pin to fit it isn't that big deal, unless its automated.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 17, 2017, 12:39:12 pm
Remember, you used to be able to purchase TO-92 with the center lead bent back already.

Ok, because of tape and reel, today, you have only these flavors A and B, C is rare: (All are top view)

A: (Too difficult to soldier on a home-made PCB)
  000

B: (Easier to solder on a home-made PCB)
O O O

C: (Obsolete, but easiest to solder + you can get a fat 10 mil trace between the pads with good clearance):
    2
    O
O     O
1      3

We would just end up purchasing type B and bend the center leg back, or type A and push it in like a tripod...

Careful, TO-18 might have pins 1&3 reversed, double check before blindly using that transistor footprint.  Just use type B's footprint, modify the center pin by pushing it up by 2.54mm.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 05:45:40 pm
(for example, a 100uF TH tantalum costs between $3 and $5 from Digi-Key, whereas a surface mount version would be less than $1).

Aren't through-hole electrolytics the cheapest?
Question for GK, Should we be using electrolytics or tantalum caps in your circuit?
I know they slightly behave differently with ESR, voltage VS cap value and temperature.

I think there are two or three tantalums recommended on the schematic, the rest are electrolytic.

I need to go back and count, but if it's only one then I guess TH wouldn't be a problem cost wise. (Sorry, laying out PCBs for a living has made me very sensitive to parts costs, I know it's not as big of a deal here, it's a hard habit to break!)

Edit: Counted, my bad, it's just one!
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 05:57:42 pm
Remember, you used to be able to purchase TO-92 with the center lead bent back already.

Ok, because of tape and reel, today, you have only these flavors A and B, C is rare: (All are top view)

A: (Too difficult to soldier on a home-made PCB)
  000

B: (Easier to solder on a home-made PCB)
O O O

C: (Obsolete, but easiest to solder + you can get a fat 10 mil trace between the pads with good clearance):
    2
    O
O     O
1      3

We would just end up purchasing type B and bend the center leg back, or type A and push it in like a tripod...

Careful, TO-18 might have pins 1&3 reversed, double check before blindly using that transistor footprint.  Just use type B's footprint, modify the center pin by pushing it up by 2.54mm.

OK, that sounds like a good plan. I agree type C is easier to solder, as they tend to stay in the PCB due to pressure from the leads pre-solder.

Type A is TO-92 JEDEC standard straight lead bulk; type B is called TO-92 2.54mm spacing lead form, "ammo pack" tape and real.

Type A are generally sold loose whereas type B comes taped on those thin cardboard bandoliers (hence ammo pack) that we all hate because it leaves a sticky residue on the pins! :D

Edit: By the way, I appreciate any and all advice on this. It's been quite awhile since I've laid out a mostly TH board designed for hand soldering. I realize doing kits designed for hand soldering and potential home etching is a lot different than boards designed for production, so these sort of tips are good reminders. :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 17, 2017, 08:30:22 pm
So, I had some time this afternoon while waiting for an appointment to redraw GK's trimmer diagram on my iPad in a vector drawing app. This is for inclusion on the schematic and possibly the silkscreen of the power supply board (since I'll have some free space there; it could also be done on the copper layer instead of silk, if those etching at home want it on their boards).

(http://timb.us/images/Scope_Pong_Diagram.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 18, 2017, 02:11:49 am
So, I had some time this afternoon while waiting for an appointment to redraw GK's trimmer diagram on my iPad in a vector drawing app. This is for inclusion on the schematic and possibly the silkscreen of the power supply board (since I'll have some free space there; it could also be done on the copper layer instead of silk, if those etching at home want it on their boards).

(http://timb.us/images/Scope_Pong_Diagram.png)


That looks good, but it might cause come confusion as the ball positions at the ends of "A" are not to scale as the circumference of the ball does not touch the boundary.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 18, 2017, 02:27:55 am
The only specified tantalum is the 100uF timing cap in the velocity integrator schematic. I specified tantalum here for the (generally) lower leakage as the capacitor is linearly charged with a rather small current (several uA). All of the other polarised capacitors can be electrolytic.

The 1uF integrator capacitors in the horizontal and vertical movement circuits shouldn't be some crappy Z5U/Y5V/etc dielectric and you probably wouldn't want to pay for COG/NPO here. The best pick is a TH polyester. 1uF is readily available in 5.08mm lead pitch in the required voltage rating range.

Similarly of the capacitors marked "*" "Polyester" in the function generator schematic can alternatively be COG/NPO ceramic types if going SMD as the capacitance values are small and the price relatively cheap - definitely do not substitute these with  Z5U/Y5V or the like.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FlyingHacker on March 18, 2017, 04:59:55 am
Incredible project. I want to be like you when I grow up... my wife is not sure when that will be, though.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 18, 2017, 10:18:28 am
So, I had some time this afternoon while waiting for an appointment to redraw GK's trimmer diagram on my iPad in a vector drawing app. This is for inclusion on the schematic and possibly the silkscreen of the power supply board (since I'll have some free space there; it could also be done on the copper layer instead of silk, if those etching at home want it on their boards).

(http://timb.us/images/Scope_Pong_Diagram.png)


That looks good, but it might cause come confusion as the ball positions at the ends of "A" are not to scale as the circumference of the ball does not touch the boundary.

Ah, good catch. I'll fix that. :)

The only specified tantalum is the 100uF timing cap in the velocity integrator schematic. I specified tantalum here for the (generally) lower leakage as the capacitor is linearly charged with a rather small current (several uA). All of the other polarised capacitors can be electrolytic.

The 1uF integrator capacitors in the horizontal and vertical movement circuits shouldn't be some crappy Z5U/Y5V/etc dielectric and you probably wouldn't want to pay for COG/NPO here. The best pick is a TH polyester. 1uF is readily available in 5.08mm lead pitch in the required voltage rating range.

Similarly of the capacitors marked "*" "Polyester" in the function generator schematic can alternatively be COG/NPO ceramic types if going SMD as the capacitance values are small and the price relatively cheap - definitely do not substitute these with  Z5U/Y5V or the like.

Just to clarify do you mean standard polyester film/foil or polyester metalized?

I assume metalized is OK (I've used metalized PET caps in S&H circuits before, so I assume that'll be fine.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 18, 2017, 11:53:23 am
PET, being the most economical and physically compact (generally), is the logical choice.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 19, 2017, 11:48:21 am
PET, being the most economical and physically compact (generally), is the logical choice.

Okay, good, that's what I had specified.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on March 20, 2017, 02:41:13 am
Are you taking orders yet?
I'm in like Flynn.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 21, 2017, 01:34:55 am
Okay, so I've got about half the schematic done now (haven't started on layout yet) and I've settled on pretty much all through hole (the JFETs being the only exception). I've calculated the area the design should take and I'm confident I can fit it on two 200x200mm boards (which will cost under $10/ea).

If there's any issues with home etching a board that size, I could always split the design up into four 100x100mm boards, but that would add some complications when it comes to interconnecting them.

Here's a 3D view showing the size of components for three of the smaller sections of the circuit. Obviously the actual area used will be larger due to routing constraints, component placement, etc.

(http://timb.us/images/Scope_Pong_4.png)
(http://timb.us/images/Scope_Pong_5.png)

I still need to go in and change the footprint for the TO-92 transistors, but the footprints and pad spacing for everything else is correct. I'm planning on using a 7.62mm spacing for the resistors. I know that normally you wouldn't want to bend the leads right at the part like that (rather you'd use a 10.16 spacing) but this isn't going to be mass produced or subject to a high vibration environment or anything, so the space savings really adds up. If there's any objection to this I could always use a 2.54 vertical footprint, but I really dislike that as it's a pain in the ass when soldering, as they don't stay in the board when soldering and are subject to more bending stress.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 21, 2017, 02:35:46 am
For your trimmers, use vertical adjustable ones.  This way, they don't need to be at the edge of the PCB, they can be easilly adjusted where ever you wish to position them.  The vertical 10/25 turn trimmers also take less PCB space.  Also, since you can't solder between the trimmer and top of the PCB, when wiring those, try to prioritize routing them on the bottom of the PCB.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 21, 2017, 06:10:38 am
I also think vertical trimmers are better for this

Also i think the layout of the components should be made so that it roughly resembles the schematic rather than going for the old school tidy all resistor in a row thing. Even if it means using resistors mounted standing up (I think such resistor mounting has a certain oldschool charm to it).

Oh and don't forget test points. I would put lots of those solder in eyelet test points all over the circuit to allow for easy testing of the blocks as well as use test points on most interblock connections so that one can see how the circuit works.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 21, 2017, 08:09:16 am
I think timb's current rendered layout is just for space approximation at this point.  To generate a nice 2 layer PCB without spaghetti traces, potentially creating some oscillators due to trace length looping around in odd ways, he will be forced to optimally re-arrange the components in each function block when routing.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 21, 2017, 10:26:26 am
Oh and don't forget test points. I would put lots of those solder in eyelet test points all over the circuit to allow for easy testing of the blocks as well as use test points on most interblock connections so that one can see how the circuit works.

Yes, test hooks are planned. :)

For your trimmers, use vertical adjustable ones.  This way, they don't need to be at the edge of the PCB, they can be easilly adjusted where ever you wish to position them.  The vertical 10/25 turn trimmers also take less PCB space.  Also, since you can't solder between the trimmer and top of the PCB, when wiring those, try to prioritize routing them on the bottom of the PCB.

All the main trimmers that adjust the geometry (stuff in the adjustment diagram) will be vertical ones, as they will be on the top board. There are a couple of other trimmers that control other stuff (like the reference voltage, etc.) and they will most likely be on the bottom board, so I've got two options there:

1) Use vertical trimmers and place a hole in the top board for an adjustment tool to fit through.

2) Use horizontal trimmers and locate them near the edge.

I don't think it's more than a couple of trimmers that will need to be on the bottom, so I may go with option 1 if I have enough space to include the holes. (I'll decide during layout.)

The reference trimmers will most likely be towards the edge of the board anyway, that's why I ended up specifying 15 turn horizontal cermet trimmers for that, but I can always change it during layout.

I think timb's current rendered layout is just for space approximation at this point.  To generate a nice 2 layer PCB without spaghetti traces, potentially creating some oscillators due to trace length looping around in odd ways, he will be forced to optimally re-arrange the components in each function block when routing.

This. That's just how the components happened to group together when importing from the schematic. As you say, I will be forced to arrange things for optimal layout. This is due to a number of factors, including: Keeping trace lengths as short as possible, routing constraints on a two layer board, component pinouts, etc.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 21, 2017, 10:40:29 am
Here's another question, for the power supply portion of the circuit I can go two ways:

1) Use one of those cute PCB mount, encased toroidal transformers (Talema and Acme are common brands). I'd have wire to board terminal blocks to bring in the AC (obviously I'd have connections for both primaries to wire it up for 120/240V).

2) BYOT: Bring your own transformer. I'd have a terminal block to accept the output of a center tapped 18V-18V transformer that would be located off-board. The diode bridge and regulators would be located on-board, of course. You could also power the board from a DC lab supply this way as well.

Chassis mount transformers are readily available if you don't have one on hand, so I'm inclined to go with option 2 (I wouldn't have to deal with creepage/clearance, fusing, etc. and it *would* save a lot of space; a 15VA PCB mount transformer is about 60x60mm).

That said, I *can* do the first option if you guys really want a complete self contained package.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on March 21, 2017, 11:06:51 am
I think a case mount transformer is a better idea.

That the PCB does not contain any dangerous voltages so you can poke around it as much as you want. Also means you can use a transformer that might be laying around or even feed it from a DC supply since the rectifiers are just going to pass it straight trough.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on March 21, 2017, 01:21:28 pm
My perspective, which is as a demo unit for kids and non electronics people.

I would like it to be as visually pleasing and as old school as possible, with aesthetics as a design constraint, though I don't feel like dead bugging it.
I will put a perspex lid on the top of it. Even the odd gimmicky LED within the case to show it off.

I can understand if you can't cater for this though.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Amazing on March 21, 2017, 04:41:27 pm
GK: Wow, nice project!  :clap: I saw this a few days ago but it took me a while to get around to logging in. 

I love the old-school analog design and it was nice to go over your schematics and be reminded of BJT circuits that I'd mostly forgotten.

Also, it's so nice to see someone jumping in to design a PCB for for this project, and everyone else helping out.  I love seeing a group excited about a project. Can't wait to see how it turns out.  :popcorn:

I tempted to build one myself, but I'm so enamored of the dead-bug aesthetic as GK presented it, that I'd probably go that route.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 21, 2017, 06:11:32 pm
Here's another question, for the power supply portion of the circuit I can go two ways:

1) Use one of those cute PCB mount, encased toroidal transformers (Talema and Acme are common brands). I'd have wire to board terminal blocks to bring in the AC (obviously I'd have connections for both primaries to wire it up for 120/240V).

2) BYOT: Bring your own transformer. I'd have a terminal block to accept the output of a center tapped 18V-18V transformer that would be located off-board. The diode bridge and regulators would be located on-board, of course. You could also power the board from a DC lab supply this way as well.

Chassis mount transformers are readily available if you don't have one on hand, so I'm inclined to go with option 2 (I wouldn't have to deal with creepage/clearance, fusing, etc. and it *would* save a lot of space; a 15VA PCB mount transformer is about 60x60mm).

That said, I *can* do the first option if you guys really want a complete self contained package.

Use #2, I would not trust high voltage mains on home etched PCBs due to possible poor etching leaving a conductive path for the mains & I fear, for some, I would rather see them use an approved AC out wallwart keeping them away from any exposed mains.  Others who know or are capable will just wire their own transformer, just make sure there is enough heat-sinking & power filtering caps to deal with an AC transformer between 15v and 18.6v.

+, this solution allows for a dual lab power supply set to +/-18v to power this project as well.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 21, 2017, 06:33:34 pm
2) Use horizontal trimmers and locate them near the edge.

You cannot predict the type of chassis the user may be placing their PCB in.  Look at GK's metal frame with the front panel.  If you place a horizontal trimmer there, the user would need to remove his PCB to adjust that trimmer.  Some chassis may have walls around all 4 sides, meaning, anytime a trimmer needs adjusting, they will need to remove their PCB from it's chassis, while functioning.  For this project, it is best to have all trimmers top vertical adjustable no matter what.  As aforementioned, this may be made and assembled by students and we want to keep thing safe and easy access to probe and play.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 21, 2017, 10:16:54 pm
2) Use horizontal trimmers and locate them near the edge.

You cannot predict the type of chassis the user may be placing their PCB in.  Look at GK's metal frame with the front panel.  If you place a horizontal trimmer there, the user would need to remove his PCB to adjust that trimmer.  Some chassis may have walls around all 4 sides, meaning, anytime a trimmer needs adjusting, they will need to remove their PCB from it's chassis, while functioning.  For this project, it is best to have all trimmers top vertical adjustable no matter what.  As aforementioned, this may be made and assembled by students and we want to keep thing safe and easy access to probe and play.

Hmm, hadn't thought about that. Fair enough! I'll use vertical ones and just put holes in the top PCB then. :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 21, 2017, 10:27:02 pm
Here's another question, for the power supply portion of the circuit I can go two ways:

1) Use one of those cute PCB mount, encased toroidal transformers (Talema and Acme are common brands). I'd have wire to board terminal blocks to bring in the AC (obviously I'd have connections for both primaries to wire it up for 120/240V).

2) BYOT: Bring your own transformer. I'd have a terminal block to accept the output of a center tapped 18V-18V transformer that would be located off-board. The diode bridge and regulators would be located on-board, of course. You could also power the board from a DC lab supply this way as well.

Chassis mount transformers are readily available if you don't have one on hand, so I'm inclined to go with option 2 (I wouldn't have to deal with creepage/clearance, fusing, etc. and it *would* save a lot of space; a 15VA PCB mount transformer is about 60x60mm).

That said, I *can* do the first option if you guys really want a complete self contained package.

Use #2, I would not trust high voltage mains on home etched PCBs due to possible poor etching leaving a conductive path for the mains & I fear, for some, I would rather see them use an approved AC out wallwart keeping them away from any exposed mains.  Others who know or are capable will just wire their own transformer, just make sure there is enough heat-sinking & power filtering caps to deal with an AC transformer between 15v and 18.6v.

+, this solution allows for a dual lab power supply set to +/-18v to power this project as well.

Yeah, that was my thought as well. Option #2 it is!

The power supply is also the only part of GK's circuit I've considered changing. I was thinking about using an LM317/LM337 (or 7815/7915) type setup instead of the discrete circuit GK shows, for a couple of reasons: Better regulation, short circuit proof, better SOA, thermal shutdown and better dropout. It would also be a lot more compact, not requiring the large TO-2 transistors of GK's design.

Of course it wouldn't be totally discrete like his design, but it's still close to era appropriate. It would also be a lot more robust for people experimenting with the circuit (I know I hate chasing down power supply issues when I'd rather be experimenting).

Again, it's up to you guys. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 21, 2017, 10:47:47 pm
I'd say stick with GK's regulators.
Then it's all discrete transistor level (no ICs).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 21, 2017, 11:37:00 pm
All top-oriented trimmers would be ideal. However, I'd be fine with a small number of trimmers on the side, preferably all on one side, so I'd only have to make access holes on one side of an enclosure (e.g., the rear panel). Assuming that heat isn't an issue, I'd even be OK with mounting the bottom board upside-down so that I could trim it from the top and bottom of an enclosure (i.e., stand it on its side with top and bottom covers removed for access to trimmers on both boards).

Regarding the power supply, having it separate makes sense for many reasons. For my own use case, I'd probably run it from a bi-polar DC lab supply given that I wouldn't be playing it often enough to justify building/dedicating a supply for it.

Speaking of enclosures, I saw the other day an Instek CRO that was mostly empty inside. Everything except the power supply and front panel electronics was on a single PCB on the bottom. The power supply was on top with lots of vacant space. One could just install this Pong project inside the scope. Then, add a switch for Scope or Pong mode. :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on March 22, 2017, 05:31:10 am
I'd say stick with GK's regulators.
Then it's all discrete transistor level (no ICs).

+1 from me.

Beside, the builder, I assumed none are totally noob with zero experience say in electronics, and remember, an oscilloscope is mandatory.

Vote for originality, as this is becoming a fun/nostalgic/aesthetic project rather than pure electronic project anymore, imho.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 23, 2017, 10:41:01 am
I'd say stick with GK's regulators.
Then it's all discrete transistor level (no ICs).

+1 from me.

Beside, the builder, I assumed none are totally noob with zero experience say in electronics, and remember, an oscilloscope is mandatory.

Vote for originality, as this is becoming a fun/nostalgic/aesthetic project rather than pure electronic project anymore, imho.

That's cool. I actually have a design I've used in the past for a fully discrete linear regulator that uses only three transistors, is short circuit proof and implements current limiting.

The design is actually built upon the simple pass regulator GK used, so with some clever layout, I can actually make it so the builder can implement either design. If you want a current limit, improved regulation and short circuit protection, just add two more small transistors, a couple of resistors plus a cap and you're set. If not, just populate the four components of the original design and solder a jumper down.

And both options are still 100% discrete. (FYI, that's the only part of the circuit I'm modifying. I've been burned quite a few times in the past by shorting part of a circuit out while probing, which leads to vaporized traces and damaged parts. All it takes is a slip of the springy ground tip on the scope probe to short something out, or a component placed backwards. The current limit on your lab supply doesn't help here, since the input filter caps of the local supply still hold significant energy.)

Hopefully this is an acceptable compromise to everyone. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 23, 2017, 12:03:11 pm
That's cool. I actually have a design I've used in the past for a fully discrete linear regulator that uses only three transistors, is short circuit proof and implements current limiting.

The design is actually built upon the simple pass regulator GK used, so with some clever layout, I can actually make it so the builder can implement either design. If you want a current limit, improved regulation and short circuit protection, just add two more small transistors, a couple of resistors plus a cap and you're set. If not, just populate the four components of the original design and solder a jumper down.

And both options are still 100% discrete. (FYI, that's the only part of the circuit I'm modifying. I've been burned quite a few times in the past by shorting part of a circuit out while probing, which leads to vaporized traces and damaged parts. All it takes is a slip of the springy ground tip on the scope probe to short something out, or a component placed backwards. The current limit on your lab supply doesn't help here, since the input filter caps of the local supply still hold significant energy.)

Hopefully this is an acceptable compromise to everyone. :)

That sounds really great!

I wanted it to remain all discrete (no ICs), so that it **Could** have been made in the 1950s/1960s etc, in principle. Authentic vintage retro (or whatever the terminology is suppose to be).

I like the idea of having the extra pair of transistors (optionally). As current limits are useful. E.g. With so many transistors/components to insert/solder, you can accidentally have a shorting solder bridge go unnoticed or have one or two components put in the wrong way round etc etc. So it would minimize the damage.

I understand your temptation to just put in LM317's. But by having it all discrete, it makes it that much more fun.
E.g. Some people make large 555 timer **IC's**, out of discrete transistors (there are kits available), just for fun!
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 23, 2017, 08:54:13 pm
That's cool. I actually have a design I've used in the past for a fully discrete linear regulator that uses only three transistors, is short circuit proof and implements current limiting.

The design is actually built upon the simple pass regulator GK used, so with some clever layout, I can actually make it so the builder can implement either design. If you want a current limit, improved regulation and short circuit protection, just add two more small transistors, a couple of resistors plus a cap and you're set. If not, just populate the four components of the original design and solder a jumper down.

And both options are still 100% discrete. (FYI, that's the only part of the circuit I'm modifying. I've been burned quite a few times in the past by shorting part of a circuit out while probing, which leads to vaporized traces and damaged parts. All it takes is a slip of the springy ground tip on the scope probe to short something out, or a component placed backwards. The current limit on your lab supply doesn't help here, since the input filter caps of the local supply still hold significant energy.)

Hopefully this is an acceptable compromise to everyone. :)

That sounds really great!

I wanted it to remain all discrete (no ICs), so that it **Could** have been made in the 1950s/1960s etc, in principle. Authentic vintage retro (or whatever the terminology is suppose to be).

I like the idea of having the extra pair of transistors (optionally). As current limits are useful. E.g. With so many transistors/components to insert/solder, you can accidentally have a shorting solder bridge go unnoticed or have one or two components put in the wrong way round etc etc. So it would minimize the damage.

I understand your temptation to just put in LM317's. But by having it all discrete, it makes it that much more fun.
E.g. Some people make large 555 timer **IC's**, out of discrete transistors (there are kits available), just for fun!

Yeah, I've got one of the discrete 555 timer kits I picked up at Bay Area Maker Faire in 2014. I even made a little adapter lead that's wired into the board and terminates into an 8-pin DIP footprint, letting you plug the giant discrete board into any circuit that uses a normal DIP 555. It's a great teaching aid to help explain the 555 and let people probe the internals in working circuits, and when not in use makes a good conversation piece!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 23, 2017, 10:55:32 pm
Yeah, I've got one of the discrete 555 timer kits I picked up at Bay Area Maker Faire in 2014. I even made a little adapter lead that's wired into the board and terminates into an 8-pin DIP footprint, letting you plug the giant discrete board into any circuit that uses a normal DIP 555. It's a great teaching aid to help explain the 555 and let people probe the internals in working circuits, and when not in use makes a good conversation piece!

I was tempted to get one of those too but haven't yet. There's a discrete 741 too which looks interesting.

I think a discrete 78xx regulator in the same style would be cool too, maybe some other classic ICs.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 24, 2017, 10:14:22 pm
Yeah, I've got one of the discrete 555 timer kits I picked up at Bay Area Maker Faire in 2014. I even made a little adapter lead that's wired into the board and terminates into an 8-pin DIP footprint, letting you plug the giant discrete board into any circuit that uses a normal DIP 555. It's a great teaching aid to help explain the 555 and let people probe the internals in working circuits, and when not in use makes a good conversation piece!

I was tempted to get one of those too but haven't yet. There's a discrete 741 too which looks interesting.

I think a discrete 78xx regulator in the same style would be cool too, maybe some other classic ICs.

I've been meaning to get the discrete 741. I'll order it one of these days.

I've also been thinking about making a discrete 317 kit. They're pretty complex internally, so it would take some work to translate from the datasheet schematic to a real, working discrete circuit (node capacitance, trace and lead inductance/resistance plus the varying parameters of discrete transistors all have to be taken into account). Still, it would be a fun project!

A tiny TL431 kit would be cool to make as well (they're actually fairly simple and schematics are available in the datasheet).  Basically it's just a couple of transistors in an op-amp configuration, a shunt voltage reference and a driver transistor on the output. It's just a matter of figuring out the hfe ratios between some of the transistors and picking the correct parts. That can be done with basic math, plus a bit of trial and error during simulation.

I've really been enjoying putting together this Scope Pong kit, so maybe I'll do a TL431 next, then a 317.

Speaking of which, I should have the Pong schematics done tonight. I'll post them here, along with a single PDF containing all of GK's schematics, for review. That way I get a few eyeballs telling me if I've missed anything.

It's taken me a bit longer than I anticipated to get the schematics finished, but my parts library in Diptrace wasn't setup for through hole, so I had to add a lot of parts. Generally I never use the Diptrace supplied library, even though it is reasonably well stocked; I have my own naming scheme for stuff and in the case of these TH parts, I wanted different pad spacing than they provided (like the 7.62 spacing for the 1/4w resistors).
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 24, 2017, 10:37:24 pm
Oh yeah, one more question for you guys: The controllers!

So the only part that actually needs to be in the controller enclosure is the 5K pot, so you won't need a board or anything for it. You can just get a small handheld plastic case from Hammond or wherever, drill a hole in the middle and install a chassis mount pot. The P1 controller will also have a push button on it for serving the ball, but again this can all be free wired right from the cable.

Now, I was looking through Digi-Key for a suitable connector to use on the Pong box and I found a good option. It's a 6-pin mini-DIN connector. They're less than a dollar and have like 15,000 in stock. There's also a mating male connector (solder cup type) available, complete with strain relief.

Now, the connector I've currently specced is PCB mount, which I figure would work out for most people. It'll be mounted on the front of the board, so if you make a custom case you can just drill a hole in the correct position. And, because of the length of the housing on male mini-DIN connectors, the board doesn't even have to be flush against the back of the front panel; think of the AT keyboard connector and how it wasn't flush against the case of old PCs.

Now, I know this may not be acceptable for some of you, because of whatever enclosure you're planning. That's alright, as Digi-Key *also* has a panel mount 6-pin mini-DIN connector available. In that case, you could just use that and solder wires between the terminals and the TH pads on the board. (Or you could use a D-sub connector, or hardwire the controllers in, whatever you want.)

For the DP4T switch, I've currently just put down labeled TH pads, so you can wire up a panel mount rotary switch.

I've made sure the TH pads on both the connector *and* switch footprints are large enough for 22AWG wire and the rings are wide enough for easy soldering.

Hopefully this will workout for those who plan to build custom cases and those who don't want to use a case. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 24, 2017, 10:54:40 pm
I've made sure the TH pads on both the connector *and* switch footprints are large enough for 22AWG wire and the rings are wide enough for easy soldering.

Choose a cheap standard terminal strip as a component for these.  This way, the user can either soldier the wires directly, or, purchase cheap terminal blocks to have the ability to screw on and off the wires.

Go with these.  I know they are large, but, this means the pad holes on the PCB you make will also be large to soldier wires directly with clearance & these terminals are also strong enough for the AC power input as well.

For 7.5mm pitch: (Recommended so that there is room for bare wires to be soldered directly on the PCB if you dont want to buy)
https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ED365 (https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ED365)
Or, for 3.5mm pitch:
https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ed555 (https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ed555)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 24, 2017, 10:59:53 pm
I've made sure the TH pads on both the connector *and* switch footprints are large enough for 22AWG wire and the rings are wide enough for easy soldering.

Choose a cheap standard terminal strip as a component for these.  This way, the user can either soldier the wires directly, or, purchase cheap terminal blocks to have the ability to screw on and off the wires.

Go with these.  I know they are large, but, this means the pad holes on the PCB you make will also be large to soldier wires directly with clearance & these terminals are also strong enough for the AC power input as well.

For 7.5mm pitch:
https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ED365 (https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ED365)
Or, for 3.5mm pitch:
https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ed555 (https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-wire-to-board/371?k=ed555)

Not a bad idea. I could put footprints down for the 3.5mm versions. I've already got the 5mm versions specced in for the input from the transformer. (I went large there so there was wide area for the GND pour to connect to.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 25, 2017, 12:18:51 am
Stick with 1 size for all.  5mm should be easy to work with and you got room for a quality trace inbetween.
3.5mm will be a little tight for hand soldiering wires if someone decides not to use terminal blocks to save the few $$$.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 25, 2017, 12:16:03 pm
Stick with 1 size for all.  5mm should be easy to work with and you got room for a quality trace inbetween.
3.5mm will be a little tight for hand soldiering wires if someone decides not to use terminal blocks to save the few $$$.

Yeah, I think you're right. I added 5mm ones last night and they look like they'll work just fine. :)

(http://timb.us/images/Scope_Pong_8.png)
(http://timb.us/images/Scope_Pong_9.png)
(http://timb.us/images/Scope_Pong_10.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on March 25, 2017, 12:56:04 pm
Nice terminal blocks. Once I used high quality Phoenix Contact blocks for a project, with press-fit (http://www.we-online.de/web/en/intelligente_systeme/technologien/massive_einpresstechnik/grundlagen/Grundlagen.php) technology, which doesn't need soldering. Now they have even simpler connectors, didn't know this SKEDD technology:

https://www.youtube.com/watch?v=yXY300wXDM4 (https://www.youtube.com/watch?v=yXY300wXDM4)

But I guess they are expensive, and they look too modern  :) But you need to connect it only once for this project, so for me just soldering wires to the board would be ok.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 26, 2017, 12:35:27 am
Nice terminal blocks. Once I used high quality Phoenix Contact blocks for a project, with press-fit (http://www.we-online.de/web/en/intelligente_systeme/technologien/massive_einpresstechnik/grundlagen/Grundlagen.php) technology, which doesn't need soldering. Now they have even simpler connectors, didn't know this SKEDD technology:

https://www.youtube.com/watch?v=yXY300wXDM4 (https://www.youtube.com/watch?v=yXY300wXDM4)

But I guess they are expensive, and they look too modern  :) But you need to connect it only once for this project, so for me just soldering wires to the board would be ok.

Yeah, the pads should be large enough to just solder wires right into it, if that's the way you want to go.

Those SKEDD blocks look pretty cool, expensive though! :)

So, I've only got one more schematic to capture tonight, the Horizontal and Vertical Deflection Circuit. I'll post the PDF in a bit for review.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: German_EE on March 26, 2017, 11:07:14 am
The quality of construction used here (which is very high) reminded me of something and it's taken me a while to find it. Have a look at this:

http://techno-logic-art.com/clock.htm (http://techno-logic-art.com/clock.htm)

It seems that this style of construction has quite a following:

http://techno-logic-art.com/images4/fc7_2.jpg (http://techno-logic-art.com/images4/fc7_2.jpg)

Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 26, 2017, 11:51:57 am
Okay guys, here's the completed schematics:

http://timb.us/PDF/Scope_Pong_20170326.pdf

Have a review, let me know if you see any errors. :)

Edit: Crap, I uploaded a slightly older version by mistake. That's missing the Multiplexer Logic, Deflection and Collision schematics. Everything else is finished in that schematic, so you can still have a look through it. I'll upload the complete version later today when I get back to my laptop.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 26, 2017, 12:22:20 pm
Looking, good...... just had a quick peek before going to bed. A few omissions immediately evident:

1) The 100uF tant. in the velocity integrator schematic really needs a voltage rating greater than the positive supply rail.
2) In the Ball Vertical Movement circuit the current limiting resistor in series with the relay contacts is missing. That 1uF will weld the reed relay's contacts without it.
3) Not a big deal, but the waveform highlighted in the Sounds Effects circuit is a squarewave rather than a triangle wave.

In the simplified Reference Regulator equivalent circuit I omitted the source impedance balancing resistor between the zener and the op-amp positive input. 

Now I'm off to bed.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 26, 2017, 12:39:47 pm
Looking, good...... just had a quick peek before going to bed. A few omissions immediately evident:

1) The 100uF tant. in the velocity integrator schematic really needs a voltage rating greater than the positive supply rail.
2) In the Ball Vertical Movement circuit the current limiting resistor in series with the relay contacts is missing. That 1uF will weld the reed relay's contacts without it.
3) Not a big deal, but the waveform highlighted in the Sounds Effects circuit is a squarewave rather than a triangle wave.

In the simplified Reference Regulator equivalent circuit I omitted the source impedance balancing resistor between the zener and the op-amp positive input. 

Now I'm off to bed.

1) I meant to ask about this. Initially I was thinking the voltage might not rise much past a diode drop above ground, but after thinking about it I can see a mode where it could rise to the upper rail.  I was trying to save a bit of space with a smaller tantalum. I'll change it.

2) I don't know how I missed that. Thanks!

3) Okay, it looked very squiggly to me in the schematic. I was thinking that node *should* be a square wave, but the drawing looked more like a very fast rise/fall triangle or something, so I thought maybe I'd missed something in my understanding of the implementation. I guess I didn't. :)

4) Ah yeah, I should have caught that too. I did that right before exporting it as a PDF.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mmagin on March 27, 2017, 01:01:41 am
I'd be quite grateful to anyone who designs a board.

What kind of frequency response does this require?  If it's sub-200 KHz, I have a good excuse to restore an antique 1940s portable oscilloscope. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 27, 2017, 08:17:25 am
I'd be quite grateful to anyone who designs a board.

What kind of frequency response does this require?  If it's sub-200 KHz, I have a good excuse to restore an antique 1940s portable oscilloscope. :)


200 KHz should be OK, but the x & y amplifiers need to be DC-coupled (have never seen an example at that vintage) and a suitable Z intensity modulation input is highly desirable.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 27, 2017, 10:28:07 am
Okay, updated the schematic with GK's issues from this morning; now includes the full schematic and BOM!

http://timb.us/PDF/Scope_Pong_20170327.pdf

Edit: Whoops, I just realized that a couple of the transistors on the Horiz. & Vert. Deflection sheet are the SMD versions instead of the correct TH variety. Ignore that in the BOM, they are supposed to be the TO-92 variant and I simply picked the wrong ones when capturing that portion of the schematic. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 27, 2017, 03:22:18 pm
I've only had a somewhat quick look, for now.

I love the way you have put the op-amp equivalent circuit, in the schematic, that is really nice and helpful!

Should the (power supply) voltage regulation circuits be in that schematic (or have I missed them and they are there ?), or are they on another sheet or something ?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mmagin on March 27, 2017, 05:49:27 pm
I'd be quite grateful to anyone who designs a board.

What kind of frequency response does this require?  If it's sub-200 KHz, I have a good excuse to restore an antique 1940s portable oscilloscope. :)


200 KHz should be OK, but the x & y amplifiers need to be DC-coupled (have never seen an example at that vintage) and a suitable Z intensity modulation input is highly desirable.

Surprisingly the scope (Waterman Pocketscope S-11-A) in question seems to have DC coupled X and Y inputs.  Might have to do something clever to give it an intensity input though via modulating the control grid.   Anyway, that's all after recapping and cleaning.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 27, 2017, 07:09:50 pm
I've only had a somewhat quick look, for now.

I love the way you have put the op-amp equivalent circuit, in the schematic, that is really nice and helpful!

Should the (power supply) voltage regulation circuits be in that schematic (or have I missed them and they are there ?), or are they on another sheet or something ?

GK did that in his hand drawn schematic, but I'd eventually like to go back and put down equivalent circuits for the rest of the schematics. There are more op amps, flip flops, monostable timers, etc. hidden away and I think it would be a great way to show people how they're made. :)

I'm still working out a couple of things with the power supply, so it's not in there yet. I'll upload a new schematic when it's ready.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 27, 2017, 07:15:31 pm
GK did that in his hand drawn schematic, but I'd eventually like to go back and put down equivalent circuits for the rest of the schematics. There are more op amps, flip flops, monostable timers, etc. hidden away and I think it would be a great way to show people how they're made. :)

I really like them, too. Great feature, Tim.

Speaking of which, for the one on the first page, "Equivilent" -> "Equivalent".
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 27, 2017, 07:23:19 pm
GK did that in his hand drawn schematic, but I'd eventually like to go back and put down equivalent circuits for the rest of the schematics. There are more op amps, flip flops, monostable timers, etc. hidden away and I think it would be a great way to show people how they're made. :)

I really like them, too. Great feature, Tim.

Speaking of which, for the one on the first page, "Equivilent" -> "Equivalent".

Thanks! 15 years of OS X's built-in spell check have made me lazy; if I don't see a squiggly red line (which obviously Windows 7 doesn't have) I assume it's correct.

I found another one earlier: On the Player 1 push button, I assume we want to "Serve" the ball, not "Sever" them! XD
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 27, 2017, 07:44:29 pm
Timb, I found an open wire on your schematic, see attached photo.
Question: You also have numerous slightly mis-positioned junctions at wired 'T' joints, I assume these are ok?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 27, 2017, 08:25:53 pm
I found another one earlier: On the Player 1 push button, I assume we want to "Serve" the ball, not "Sever" them! XD

Yes. "Sever" might be more along the lines of Fruit Ninja. ;D
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 27, 2017, 10:11:30 pm
Timb, I found an open wire on your schematic, see attached photo.
Question: You also have numerous slightly mis-positioned junctions at wired 'T' joints, I assume these are ok?

Ah, good catch! Thanks.

Can you elaborate on the mis-positioned junctions? I'm not sure I see what you mean.

Edit: I think I see what you mean. Like C504 and R502 and in this picture?

(https://uploads.tapatalk-cdn.com/20170327/137b9996ba7b7e61e2659c4cde3735be.jpg)

They're connected properly, but for whatever reason the connection dot is off center (I might have pushed the wires and the dot just messed up.)

I've just gone through and noted all the ones I could find, I'll fix it tonight.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 27, 2017, 10:44:40 pm
Oh yeah, something else: Any wires shown in orange are off-board connections that terminate to the board in a terminal block. Hopefully that was clear.

There's no provision in DipTrace for that sort of thing, so I made several components (pots, a push button switch and a rotary switch) that didn't have any pin connections, that way they would show up on the BOM. I then proceeded to manually draw the wires out (in orange) showing the connections to the terminal blocks.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 28, 2017, 12:24:54 am
If those are connected, then everything else looks fine...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 28, 2017, 02:39:07 am
Timb, you forgot to label the Z axis output connector and will you be providing an optional inverted Z axis output?  It would only require an additional transistor and 3 resistors.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 28, 2017, 08:56:57 am
Alternatively you can just add a jumper to select either the flip-flops Q or !Q.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 28, 2017, 09:01:32 am
I've only had a somewhat quick look, for now.

I love the way you have put the op-amp equivalent circuit, in the schematic, that is really nice and helpful!

Should the (power supply) voltage regulation circuits be in that schematic (or have I missed them and they are there ?), or are they on another sheet or something ?

GK did that in his hand drawn schematic, but I'd eventually like to go back and put down equivalent circuits for the rest of the schematics. There are more op amps, flip flops, monostable timers, etc. hidden away and I think it would be a great way to show people how they're made. :)


This is what I am currently working on and all pages/diagrams will eventually get collated into a single PDF document. Attached is the equiv. diagram of the sounds effects circuit:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303332;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 28, 2017, 09:10:59 am
Incidentally, I have since noticed a (nearly inconsequential) error in the sound effects circuit. In the posted video you'll notice that the higher pitched beep (1200 Hz) occurs when the ball hits a paddle while the lower pitched beep (600 Hz) occurs when the ball hits a boundary.

In my original circuit diagram I've got the 1200 Hz and the 600 Hz swapped around, which would cause the opposite to happen.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 28, 2017, 09:43:03 am
If those are connected, then everything else looks fine...
I went ahead and fixed them anyway. Turns out it's some sort of issue with how the nodes were reproduced when I copied/pasted various circuit blocks. (There's a lot of repeated circuit blocks, so it saves time to do it that way.)
 
Alternatively you can just add a jumper to select either the flip-flops Q or !Q.

I was considering tapping off the other side of the flip-flop but wanted to run it by you.

Timb, you forgot to label the Z axis output connector and will you be providing an optional inverted Z axis output?  It would only require an additional transistor and 3 resistors.

The labeling is fixed in tonight's version. The Z-axis Inv will be added in the next version.

This is what I am currently working on and all pages/diagrams will eventually get collated into a single PDF document. Attached is the equiv. diagram of the sounds effects circuit:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303332;image)

Wow, that looks great! Feel free to share as you go along and I'll move it over to the digital schematic as well.

Okay, here's tonight's version of the schematic:

http://timb.us/PDF/Scope_Pong_20170328.pdf

Changes:
Fixed connection between C606 and R640.
Fixed wire junctions. (I think I got these all, please point out any wires that connect without an appropriate (or shifted) callout.)
Changed polarized cap symbols.
Removed polarization symbol from bi-polar AE capacitor components.
Removed polarization sign silkscreen from bi-polar AE capacitor patterns.
Added part numbers and manufacturers to all items but ceramic caps and resistors in the BOM.
Added labeling per GK's schematic.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 28, 2017, 11:03:28 am
Wow, that looks great! Feel free to share as you go along and I'll move it over to the digital schematic as well.


Okay, here is the Function Generator.......

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303377;image)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 28, 2017, 12:06:21 pm
Wow, that looks great! Feel free to share as you go along and I'll move it over to the digital schematic as well.


Okay, here is the Function Generator.......

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303377;image)

Sweet!

What time base is the scope set to on those waveforms? It would be good to document that for in use debugging and troubleshooting. (To know what frequency the signals should optimally be, along with the voltage range.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 28, 2017, 12:29:36 pm
It's 50uS/div. I can add that I guess. The nominal operating frequency of the function generator is 4800Hz. My 10nF timing cap measures almost 10% high (the upper limit of the tolerance range), so f measures ~4400Hz, but that is perfectly OK.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on March 28, 2017, 09:42:37 pm
Great to have the waveforms on the schematic. Like the old days of CRT TVs and Video Cassette players.  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 28, 2017, 10:34:03 pm
And good old test equipment service manuals.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on March 28, 2017, 10:41:27 pm
Great to have the waveforms on the schematic. Like the old days of CRT TVs and Video Cassette players.  :-+

That is nearly exactly what I thought. The schematic does seem to have a sort of vintage look to it (in a NICE way!).
Which goes well with the entire project.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 28, 2017, 10:44:36 pm
And good old test equipment service manuals.

Yes! You know I realized not too long ago that the way I draw schematics mirrors the schematics from old service manuals. I tend to put a lot of waveforms and instructional callouts in them. I even got in the habit of doing it the way Tektronix did if I had a lot of waveforms I needed to show (that is, putting the waveforms on a separate sheet and placing a symbol and letter next to the location of that waveform on the actual schematic).

Since I don't do nearly as much analog work these days there's not a lot of waveforms to show, but it's still helpful for things like how the power supplies should ramp up, or the correct timing on a digital bus. My customers seem to really like it and it ends up being good documentation instead of just a schematic.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 28, 2017, 10:46:40 pm
Thanks for all the time you're putting into this, Tim. I'm looking forward to exploring all the analog goodness along with your schematics/docs.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 28, 2017, 11:02:43 pm
Thanks for all the time you're putting into this, Tim. I'm looking forward to exploring all the analog goodness along with your schematics/docs.

I appreciate that! However, to be fair GK really did all the hard work in creating the project and documenting it by hand. Making a digital schematic is a cakewalk by comparison. I'm really glad GK has been OK with me doing this; bringing such a cool project to other people feels good. :)

Now the hard (and fun) part for me has arrived for me: Doing the layout! I'm going to start tonight, but man, this is going to be a *beast* to route. It didn't really hit me until I looked at the complete BOM: Over 700 parts! Nearly 200 transistors, 200 diodes, hundreds of resistors! All on two, 2-layer boards.

I've routed digital boards with twice as many parts, so you'd think it would be easy, but that was on a 6-layer board and a lot of the routing was simple busses going from one part to the next.

When I first start a new project, as soon as I see (or finish) the schematics my mind instantly starts chewing on how it could be routed. So the auto-router in my brain has been going non-stop since GK first posted the schematics awhile back. It's been a fantastic mental puzzle to work on and I can't wait to start this evening.

I'll post screenshots of my progress each night for comments and review, if you guys want.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 28, 2017, 11:13:01 pm
Take it a section/function module at at time.  Don't be pressed to fit each section into the smallest most compact possible layout.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 28, 2017, 11:23:15 pm
Take it a section/function module at at time.  Don't be pressed to fit each section into the smallest most compact possible layout.

Yeah, I've already got all the parts grouped by sheet to start with. Obviously it won't stay like that for the entire board, as some things will have to mix in order to route the nets in the available space.

Space is an issue, however I think I've got a solution lined up if I end up running out of it, without going to a third full sized board.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on March 28, 2017, 11:33:13 pm
Take lots of short rests from the routing Tim, each one will freshen the mind and you'll see paths, solutions and things you were too tired or cross eyed to see.
Keen to see you efforts.  :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 28, 2017, 11:33:39 pm
Thanks for all the time you're putting into this, Tim. I'm looking forward to exploring all the analog goodness along with your schematics/docs.

I appreciate that! However, to be fair GK really did all the hard work in creating the project and documenting it by hand. Making a digital schematic is a cakewalk by comparison. I'm really glad GK has been OK with me doing this; bringing such a cool project to other people feels good. :)

Very true. Thank you GK for sharing your project with us!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 29, 2017, 09:33:20 am
Very true. Thank you GK for sharing your project with us!



No problem. The equivalent circuit of the Multiplexer Logic. I'm only able to churn these out one sheet per evening...............

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303578;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on March 29, 2017, 09:49:54 am
Its awesome !  :-+

Not only the board, the documentation is now like old Tek's style, attached example of old Tek's schematic.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 29, 2017, 10:42:47 am
Okay, here's today's updates:

Laid out the reference regulator:

http://timb.us/PDF/Scope_Pong_Reference_Regulator.pdf
(Orange traces are bottom layer, black is top, pads with no connection connect to GND pour.)

(http://timb.us/images/Reference_Regulator_1.png)
(http://timb.us/images/Reference_Regulator_2.png)
(http://timb.us/images/Reference_Regulator_3.png)

I think I could make it a bit more compact and there's a couple of places where I could perhaps position things more efficiently, but it's a good start.

I also added an option for an inverted Z-Axis output.

(http://timb.us/images/Scope_Pong_Z-Select.png)

I've updated the schematic to reflect this change:

http://timb.us/PDF/Scope_Pong_20170329.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 29, 2017, 12:51:30 pm
Looks neat; I think you'll have this knocked off in no time  :)

I'm currently finalizing/polishing/amending my own schematics and I think a few more bypass capacitors should be added for good measure. The -15V rail of the Reference Regulator should be bypass to ground with an additional 100nF cap. Also the "inverter" op-amp in the Velocity Integrator schematic should have both its supply rails bypassed to ground with an additional pair of 100nF.

That should be sufficient. In my rats nest build I actually have plentiful 100nF bypass caps littered all around as they double as structural support for the components suspended above the ground plane. I just neglected those ones mentioned above when I scribbled the schematics.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 29, 2017, 12:55:17 pm
I'm only able to churn these out one sheet per evening...............


OK, I lied, LOL. Here is the equivalent diagram for the Vertical Ball Movement circuit. Now I really have to log off and go to bed; I'm going to be a zombie at work again tomorrow, but then again being a public servant I guess no one will notice anything out of the ordinary  :P.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=303619;image)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 29, 2017, 01:18:55 pm
Looks neat; I think you'll have this knocked off in no time  :)

I'm currently finalizing/polishing/amending my own schematics and I think a few more bypass capacitors should be added for good measure. The -15V rail of the Reference Regulator should be bypass to ground with an additional 100nF cap. Also the "inverter" op-amp in the Velocity Integrator schematic should have both its supply rails bypassed to ground with an additional pair of 100nF.

That should be sufficient. In my rats nest build I actually have plentiful 100nF bypass caps littered all around as they double as structural support for the components suspended above the ground plane. I just neglected those ones mentioned above when I scribbled the schematics.

I actually planned to add a bunch of additional bypassing around the board on the + and - 15V rails. Those will be on the power supply schematic once I finalize the design of my supply. (I'm waiting on a set of complementary darlingtons to arrive from Digi-Key to solder up a test circuit and verify stability. Simulations came out fine, but I want to be sure before committing it to real boards.)

I figured adding a bunch additional bypass was a good idea, considering the rails will be bussed across two large boards. I had also planned on adding footprints for a couple of small bulk caps at a couple of key points along the route. (They most likely won't be needed, but I'd rather have provisions for them just in case, so I don't have to bodge something in or spin another set of boards.)

Experience has taught me you can rarely have too much capacitance on a power rail. (Well, depending on the regulator technically you can, but...)

The latest equivalent circuit diagrams look great!

Also, are you keeping a log of any changes/amendments you make to your schematics? That would make it easier to back-annotate mine. (I don't mind doing it the old fashioned way, I just don't want to miss anything that may be critical.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 29, 2017, 01:38:35 pm
Besides those three additional bypass caps I haven't made any electrical ammendments. Everything is hunkydory in that regard. Ammendments have just been minor annotations, component designators to link to the equivalent diagrams. When done I'll upload the lot to that pong folder on my site and delete the old.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 29, 2017, 03:01:54 pm
Timb, you got the center leg of the TO-92 bent to the front instead of toward the back where the round side of the case.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 29, 2017, 06:57:43 pm
Timb, you got the center leg of the TO-92 bent to the front instead of toward the back where the round side of the case.

That's the way I've seen it done before in some old test gear, so I thought it was the standard. There's even a footprint for it like that, including 3D model, in DipTrace. (Though I ended up making my own footprint with a slightly different silkscreen, and my own 3D model with better looking leads.)

Come to think of it, I have actually seen the front pin bent toward the back on some TO-92s too. In this case, I basically copied the existing footprint and didn't give it much thought, as there's little documentation on the subject.

If it makes a big difference I can change it, not a big deal. (Though, keep in mind you're going to have to bend the leads out yourself either way, no matter what.

Edit: The only image of a TO-92 I can find with a bent center leg has it going backward, so I'll change it to that since it seems more common. I *have* seen them bent forward, maybe they're non-standard like that or something.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on March 29, 2017, 07:47:04 pm
Any of the new TO-92 I have that have bent leads are backwards to the round side.
AFAIK it's the more common configuration. Other will chime in I guess.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 29, 2017, 11:32:01 pm
My recollection is that the center pin is bent toward the rounded side of the package (not that I really track common usage of the layout).

Aesthetically, it makes more sense to me for the center pin to be toward the rounded side because then the pins create a triangle where one side aligns with the flat side of the package (rather than having a vertex there). Also, it tends to center the package over the holes in the PCB, thereby making better use of the area.

Nevertheless, as long as it's consistent on all the PCBs for the project, I don't have a preference.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 30, 2017, 12:06:47 am
The transistor also takes less PCB surface area if the center leg is bent to the rounded side.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on March 30, 2017, 12:14:00 am
There's no official standard, I've seen it done both ways. Just go with whatever makes the layout simplest to create, you can even have some one way and some the other way if that makes placement easier. It's not as if it's difficult to form the leads, although consistency does make it less likely for an assembly error to creep in.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 30, 2017, 07:53:55 am
I've updated the schematic to reflect this change:

http://timb.us/PDF/Scope_Pong_20170329.pdf (http://timb.us/PDF/Scope_Pong_20170329.pdf)


C508 in the audio amplifier is 100nF instead of 100pF.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 30, 2017, 10:08:17 am
I've updated the schematic to reflect this change:

http://timb.us/PDF/Scope_Pong_20170329.pdf (http://timb.us/PDF/Scope_Pong_20170329.pdf)


C508 in the audio amplifier is 100nF instead of 100pF.

Good catch, thanks! Will fix today.

Okay, I fixed the the TO-92 pins:

(http://timb.us/images/Ref_Reg_r002a.png)

I had the change the routing a bit to cope with the new pin configuration. To be honest, I think it would have ultimately been easier to route with the pins the other way, but I was able to make things a bit more compact with the new footprint, so it's all good. (I don't want to squeeze things any closer than this, to allow for easy probing of parts of the circuit that don't have test points.)

http://timb.us/PDF/Scope_Pong_Reference_Regulator_r002a.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 30, 2017, 10:16:39 am
There's no official standard, I've seen it done both ways. Just go with whatever makes the layout simplest to create, you can even have some one way and some the other way if that makes placement easier. It's not as if it's difficult to form the leads, although consistency does make it less likely for an assembly error to creep in.

Yeah, I'll stick with one way or the other in this case. If it was a small circuit with a dozen transistors it would be one thing, but this is hundreds, so I think keeping it simple is the way to go.

I've also added a little NPN and PNP silkscreen symbol to the center of the footprints, to aid in correctly populating the boards. (This isn't shown in the photo/PDF above.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 30, 2017, 07:22:09 pm

I had the change the routing a bit to cope with the new pin configuration. To be honest, I think it would have ultimately been easier to route with the pins the other way, but I was able to make things a bit more compact with the new footprint, so it's all good. (I don't want to squeeze things any closer than this, to allow for easy probing of parts of the circuit that don't have test points.)


Do not worry about this.  You re-worked an existing routed section.  You will not have this issue as you start routing the rest of the PCB fresh.  Just rotating some of the transistors by 180 or 90 degrees in the current section would have simplified routing quite a bit, but for such a large circuit, leave it the way it is, it's perfectly fine.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on March 30, 2017, 09:32:10 pm
I had the change the routing a bit to cope with the new pin configuration. To be honest, I think it would have ultimately been easier to route with the pins the other way, but I was able to make things a bit more compact with the new footprint, so it's all good. (I don't want to squeeze things any closer than this, to allow for easy probing of parts of the circuit that don't have test points.)

Looks great!
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 31, 2017, 01:36:17 am

I had the change the routing a bit to cope with the new pin configuration. To be honest, I think it would have ultimately been easier to route with the pins the other way, but I was able to make things a bit more compact with the new footprint, so it's all good. (I don't want to squeeze things any closer than this, to allow for easy probing of parts of the circuit that don't have test points.)


Do not worry about this.  You re-worked an existing routed section.  You will not have this issue as you start routing the rest of the PCB fresh.  Just rotating some of the transistors by 180 or 90 degrees in the current section would have simplified routing quite a bit, but for such a large circuit, leave it the way it is, it's perfectly fine.

Yeah, it occurred to me while reviewing the PDF after my last post that I could have simplified a couple of routes by rotating the transistors, but I'd have to tear out a bunch of other routes and move some other components, but I don't want to go down that rabbit hole.

I think that routing large boards like this requires you to be more practical than perfectionist. The layout needs to be good enough to route everything on two layers *and* be compact enough to fit everything in the limited space, however, at a certain point you just have to say it's as good as you can practically get, otherwise you'll never make any real progress.

But yeah, I'm having a good time with this. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on March 31, 2017, 02:49:51 am
Your doing perfectly fine...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 31, 2017, 12:12:30 pm
Tonight I got the Velocity Integrator section finished.

Here's the Velocity Integrator:

(http://timb.us/images/Velocity_Integrator_1.png)
(http://timb.us/images/Velocity_Integrator_2.png)
(http://timb.us/images/Velocity_Integrator_3.png)

http://timb.us/PDF/Scope_Pong_Velocity_Integrator.pdf

The Function Generator section is coming along nicely as well and I'm about 3/4 done with it. It's actually coming along quite quickly and the routing isn't bad at all. I should have at least that and another section finished tonight. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on March 31, 2017, 12:37:37 pm
Good progress, but I'd still prefer to see those two op-amp supply rail bypass caps (100nF) within the Velocity Integrator border. Ditto with the missing 100nF -15V bypass on the -REF op-amp, within the reference reg. border.


 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 31, 2017, 05:31:36 pm
Good progress, but I'd still prefer to see those two op-amp supply rail bypass caps (100nF) within the Velocity Integrator border. Ditto with the missing 100nF -15V bypass on the -REF op-amp, within the reference reg. border.

Yeah, they'll be there! All the additional bypass caps we talked about will be placed just inside each section's border where they branch off the main power buss, so once I route that I'll place them.

I already went back and fixed the -REF op-amp's missing bypass since the last screen shot of that section. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on March 31, 2017, 06:40:31 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on March 31, 2017, 08:17:29 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

In general, for hole size I'll use component lead diameter + lead tolerance + 0.05mm (to account for plating) + 0.1mm (as a safety margin). That's worked out extremely well in the past.

Minimum annular ring is twice the hole diameter. For large components I'll use much larger pads, to help anchor them down and prevent the pads from lifting from the extra heat needed durning soldering.

I'll grab some measurements of the pad sizes for the components on the board tonight and post them. I think most of them should be acceptable, though I'm not happy with the pad sizes for the diodes, I think they need to be a bit bigger.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 01, 2017, 12:13:39 am
Great to have the waveforms on the schematic. Like the old days of CRT TVs and Video Cassette players.  :-+
And of course the schematic should be on one huge folded paper sheet with all wires shown.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 01, 2017, 12:19:43 am
I definitely think there is potential for someone to do this as a kit - The Evil Mad Scientist guys come to mind.

Bay Area Maker Faire is May 19th, Just sayin'....



Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Ultrawipf on April 01, 2017, 12:32:10 am
Woah. Impressive.
Considering it is all discrete components i would have expected it to be much more complicated for that level of logic complexity and how smooth it looks on the scope.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 01, 2017, 01:00:45 am
If you're going to the effort of doing a PCB, some suggestions :

Where power comes into each section, run it through a pair of pads with a track linking them, so for faultfinding you can cut and re-link neatly, or fit a 2x2 0.1" pin header to take shorting jumpers.

How easy would it be to add I/O for an optional on-screen scoring add-on board?
I think onscreen digits would be doable with a  diode matrix for characters,or you could do LED displays (minitron filament displays for period accuracy), or nixies. A long time ago ISTR seeing an idea from the 60's for vector digit generation using various LC circuits to combine sine & cosines to form digits for vector displays.

I think one big board will have some visual appeal - perhaps a layout  that can easily be done as a large PCB or split into smaller stacked ones.

If you're looking towards a kit, it would be nice if there was an option to avoid dealing with mains - might it be feasible to do something like a rail splitter to run from a 24VDC power brick?
A possible issue here is that some of these PSUs have output -ve connected to mains earth. Maybe a +12 to -12 inverter?
Or maybe from 12VAC from an off-the-shelf halogen lighting transformer, with a charge pump inverter for the -ve rail.



 


Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: nil on April 01, 2017, 02:15:40 am
This is an awesome project to see since I've only ever done this game in software.

I couldn't help but wonder how much more complicated it would be to change the bounce angle so it wasn't always 90 degrees.. for example, when I did pong in software, I used the ball's distance bouncing from the center of the paddle to modulate the bounce angle. dead center gives 90 degrees. the closer to the edge it got, the shallower the bounce (such that when it hit the extreme edge of the paddle, it would bounce almost completely vertically (but still enough angle to send it towards the other side)...  a circuit to implement this idea is not immediately clear to me in my head, anyway.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 04:25:02 am
How easy would it be to add I/O for an optional on-screen scoring add-on board?
I think onscreen digits would be doable with a  diode matrix for characters,or you could do LED displays (minitron filament displays for period accuracy), or nixies. A long time ago ISTR seeing an idea from the 60's for vector digit generation using various LC circuits to combine sine & cosines to form digits for vector displays.


You'd just have to (for a non-"on-screen" score counter) break out the "Paddle hit" and "End match" lines for a score counter. This could be a counter for each paddle, which increments every time a paddle makes a successful hit. To discriminate between paddles one edge-triggered counter would increment on the positive transition of "Paddle hit" while the other counter would trigger on the negative edge.
However some gating will be required to prevent a miss of the ball which ends a match from registering on the respective paddle counter as a successful hit. On a match-ending miss, "End match" goes high in response to a toggle of "Paddle hit". To form the clock for the score "hit" counter, "Paddle hit" will need to be delayed first and then ANDed with the inverse of "End Match". The delay just needs to be long enough so that the version of "Paddle hit" clocking the score counters cannot change state before "End match" goes high (this could be implemented rather trivially with an RC delay prior to a gate with a purposely defined logic threshold). When the "Serve ball" pushbutton is pressed to start a new match, "End match" goes low. This could clock a negative edge-triggered monostable providing a reset pulse to return the score counters to zero at the commencement of a new match. I think a cool display for the score counter would be seven-segment LED displays made up of discrete 3mm LEDs, say four in a row per segment. The score counters would be two digits each.   

This is all rather trivial from a design perspective and I could knock up the schematics for a score counter module as described, if Timb just routes the mentioned lines (along with GND and +15V) to a 4-pin header. This module could be built as an optional design if desired and just connected by plugging into said header. However it won't be a trivial number of additional components to solder - Four 4-bit BCD counters with seven segment decoding and the associated control logic would take at least 80 transistors, not to mention the diodes and passives.....



An on-screen score display would put the entire project in another league of complexity. I know precisely, because I have 100% designed it already - That will actually eventually be an analogue implementation using integrated circuit op-amps, comparators, switches and logic, however, for the sake of my sanity.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 01, 2017, 04:31:09 am
A 7-segment score counter would be a nice way to do it to avoid the complexities of on-screen scoring. Since it'd be an add-on module instead of on-board, it could also use ICs and 7-segment digits if one didn't want to go to the complexities of discrete circuitry. Hide it all in its own enclosure if the clash of aesthetics would be too jarring.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 01, 2017, 04:39:26 am
I would stay away from 7 segment displays and any logic IC for counting and 7 seg decoding.  I would like to keep everything discrete.  Either 10 leds for each player using simple transistors to shift increment the score, or, with the exact same transistor shift increment, provided the output transistors are open-collector and can withstand the HV, send the 10 outputs to nixie tubes for a 0 to 9 count display.

Basically, 1 all transistor circuit, 2 optional displays, 1 LV for leds, of with an HV supply, nice numeric tube display.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 01, 2017, 04:42:46 am
You can certainly do that since the proposal is for the score counting and display to be a separate circuit connected via header. Make it any way you like. Nixie tube scoreboard?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 05:42:58 am
Come to think of it, how would you like the score counter implemented?. I think my initial idea detailed in my previous post of counting paddle hits for each player wouldn't be of much use in 2-player mode. The looser of a match is whoever misses the ball, and the number of paddle hits between players, which can only differ by one count, really doesn't matter.

I guess I was still thinking of playing in 1-player mode against the machine. Here you are playing against an invincible opponent and the ball velocity will eventually become too fast for a human player to keep up, so counting the paddle hits would be a good method of scoring; the better you get at the game the more hits you'll be able make before inevitably loosing to the machine.

In two player mode it would be better to have the score counters increment every time a match is won, rather than every time a paddle is hit. To accommodate the two player mode the score counters could be provided with a manual reset button; this button is pressed to zero the counters and the players then agree to the winner being the first to register, say, ten or twenty match wins.

Once again the logic for all if this would be rather trivial. The score counters are now incremented whenever "End match" goes high and the logic level of "Paddle hit" indicates which player missed the ball, so determines which of the two counters is incremented.

However if both the 1-player and 2-player scoring methods as now detailed are desired a third pole will need to be added to the "Mode" control switch, wired to the score counter control logic, so that the scoring counter knows if either a 1-player or a 2-player game is being played.
   

 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 05:54:51 am
Might as well mention it; The other night in a fit of immodesty for the first time I tipped a personal project for the Hackaday blog! :D

Here is it:

http://hackaday.com/2017/03/31/jaw-dropping-ic-free-pong-on-an-oscilloscope/ (http://hackaday.com/2017/03/31/jaw-dropping-ic-free-pong-on-an-oscilloscope/)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 01, 2017, 07:41:09 am
Might as well mention it; The other night in a fit of immodesty for the first time I tipped a personal project for the Hackaday blog! :D

Here is it:

http://hackaday.com/2017/03/31/jaw-dropping-ic-free-pong-on-an-oscilloscope/ (http://hackaday.com/2017/03/31/jaw-dropping-ic-free-pong-on-an-oscilloscope/)

Reading the comments there. Some have already noticed it is an April fools joke!  :o :o :o :o :o

NO IC's, that is impossible!

If they are reading this, then I can confirm it is NOT an April 1st joke, it seems to be real!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 08:38:09 am
If they are reading this, then I can confirm it is NOT an April 1st joke,


Oh come on now, don't spoil the fun already.  :P

Seriously though, Dan Maloney put a link to this thread (where I think the reality of this project is quite comprehensively documented) in his first paragraph.
Some people don't seen to exhibit a great deal of curiosity prior to posting comment! This isn't anything that warrants much more than a ::) though!
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 10:07:53 am
Okay, I finished a medium sized section tonight, the Multiplexer Logic:

(http://timb.us/images/Multiplexer_Logic_1.png)
(http://timb.us/images/Multiplexer_Logic_2.png)
(http://timb.us/images/Multiplexer_Logic_3.png)

http://timb.us/PDF/Scope_Pong_Multiplexer_Logic.pdf

I didn't get the Function Generator section done, but I'm close there as well. (I ran into some routing constraints so took a break; I've since figured out a suitable route so I'll go back to it tonight and finish up.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 01, 2017, 10:13:33 am
I would stay away from 7 segment displays and any logic IC for counting and 7 seg decoding.  I would like to keep everything discrete.  Either 10 leds for each player using simple transistors to shift increment the score, or, with the exact same transistor shift increment, provided the output transistors are open-collector and can withstand the HV, send the 10 outputs to nixie tubes for a 0 to 9 count display.

Basically, 1 all transistor circuit, 2 optional displays, 1 LV for leds, of with an HV supply, nice numeric tube display.
Some sort of 1-of-n ring counter would certainly be easier, though a diode matrix could do 7-seg decode easily from a 1-of-x output.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 10:23:15 am
If you're going to the effort of doing a PCB, some suggestions :

Where power comes into each section, run it through a pair of pads with a track linking them, so for faultfinding you can cut and re-link neatly, or fit a 2x2 0.1" pin header to take shorting jumpers.

How easy would it be to add I/O for an optional on-screen scoring add-on board?
I think onscreen digits would be doable with a  diode matrix for characters,or you could do LED displays (minitron filament displays for period accuracy), or nixies. A long time ago ISTR seeing an idea from the 60's for vector digit generation using various LC circuits to combine sine & cosines to form digits for vector displays.

I think one big board will have some visual appeal - perhaps a layout  that can easily be done as a large PCB or split into smaller stacked ones.

If you're looking towards a kit, it would be nice if there was an option to avoid dealing with mains - might it be feasible to do something like a rail splitter to run from a 24VDC power brick?
A possible issue here is that some of these PSUs have output -ve connected to mains earth. Maybe a +12 to -12 inverter?
Or maybe from 12VAC from an off-the-shelf halogen lighting transformer, with a charge pump inverter for the -ve rail.

Already planned on adding solder pad power links for each section.

It would be difficult to do this as a single, large PCB due to cost reasons. You'd need at least a 400x400mm PCB; I did research this but costs seem to start going way up once you go over 200x200. My current plan is to stack two 200x200mm boards.

I have a source for 24VCT plug packs, so that could always be an option. You could always also use two separate 18VDC laptop type adapters or a bench supply.

I'll make sure the nets needed for scoring are brought out to the board to board headers, so a scoring add-on could be plugged in.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 10:31:23 am
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

As promised:

(http://timb.us/images/Pad_Sizes.png)

http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 10:54:07 am
I would stay away from 7 segment displays and any logic IC for counting and 7 seg decoding.  I would like to keep everything discrete.  Either 10 leds for each player using simple transistors to shift increment the score, or, with the exact same transistor shift increment, provided the output transistors are open-collector and can withstand the HV, send the 10 outputs to nixie tubes for a 0 to 9 count display.

Basically, 1 all transistor circuit, 2 optional displays, 1 LV for leds, of with an HV supply, nice numeric tube display.

What about printing the score on the screen? In an earlier thread on a DIY analog computer, someone (possibly GK?) calculated the patterns needed to print numbers to a scope in a purely analog fashion, so that *could* be used, though I'm not sure how complex the implementation would be.

Failing that you could do a pair of discrete resistor ladder DACs for X and Y; the data for drawing the numbers would come from a ROM (you could use an array of diodes in place of the ROM to stay discrete), then just raster scan them out during a multiplexing time slot. That's how Tektronix did readouts on their CRT based scopes.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 11:03:36 am
For basic through-hole home-brew stuff I use a 50/100 thou grid. Small-signal component leads get big 80 thou. dia. pads with 32 thou (0.8mm) dia. holes exclusively. This makes for easy manual manufacture still allows a decent packing density. 671 individual components on this 150mm x 300mm board (from another project that I am steadily beavering away at behind the scenes......):

(https://www.eevblog.com/forum/projects/homebrew-digital-computer-system/?action=dlattach;attach=113606;image)

(https://www.eevblog.com/forum/projects/homebrew-digital-computer-system/?action=dlattach;attach=113051;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 11:10:34 am
I would stay away from 7 segment displays and any logic IC for counting and 7 seg decoding.  I would like to keep everything discrete.  Either 10 leds for each player using simple transistors to shift increment the score, or, with the exact same transistor shift increment, provided the output transistors are open-collector and can withstand the HV, send the 10 outputs to nixie tubes for a 0 to 9 count display.

Basically, 1 all transistor circuit, 2 optional displays, 1 LV for leds, of with an HV supply, nice numeric tube display.

What about printing the score on the screen? In an earlier thread on a DIY analog computer, someone (possibly GK?) calculated the patterns needed to print numbers to a scope in a purely analog fashion, so that *could* be used, though I'm not sure how complex the implementation would be.

Failing that you could do a pair of discrete resistor ladder DACs for X and Y; the data for drawing the numbers would come from a ROM (you could use an array of diodes in place of the ROM to stay discrete), then just raster scan them out during a multiplexing time slot. That's how Tektronix did readouts on their CRT based scopes.


But you've just ~doubled the complexity of the project. If you want to accommodate that as an optional add-on the current multiplexer logic will have to be scrapped and majorly redesigned for a start. I say just stick to the current specification.


Also, yes, that was me in the analog computing thread where development of my "Fourier synthesis character generator" was documented:
http://www.glensstuff.com/fouriersynthchargen/fouriersynthchargen.htm (http://www.glensstuff.com/fouriersynthchargen/fouriersynthchargen.htm)
   
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 11:17:59 am
I would stay away from 7 segment displays and any logic IC for counting and 7 seg decoding.  I would like to keep everything discrete.  Either 10 leds for each player using simple transistors to shift increment the score, or, with the exact same transistor shift increment, provided the output transistors are open-collector and can withstand the HV, send the 10 outputs to nixie tubes for a 0 to 9 count display.

Basically, 1 all transistor circuit, 2 optional displays, 1 LV for leds, of with an HV supply, nice numeric tube display.

What about printing the score on the screen? In an earlier thread on a DIY analog computer, someone (possibly GK?) calculated the patterns needed to print numbers to a scope in a purely analog fashion, so that *could* be used, though I'm not sure how complex the implementation would be.

Failing that you could do a pair of discrete resistor ladder DACs for X and Y; the data for drawing the numbers would come from a ROM (you could use an array of diodes in place of the ROM to stay discrete), then just raster scan them out during a multiplexing time slot. That's how Tektronix did readouts on their CRT based scopes.


But you've just ~doubled the complexity of the project. If you want to accommodate that as an optional add-on the current multiplexer logic will have to be scrapped and majorly redesigned. I say just stick to the current specification.


Also, yes, that was me in the analog computing thread where development of my "Fourier synthesis character generator" was documented:
http://www.glensstuff.com/fouriersynthchargen/fouriersynthchargen.htm (http://www.glensstuff.com/fouriersynthchargen/fouriersynthchargen.htm)
   

Yeah, I concur it would majorly up the complexity. I just thought I'd throw it out there. :D

Personally, I think using some of those cute HP bubble 7-seg displays or even just a row of individual LEDs would be the way to go.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 11:25:33 am
Yeah, just route the "End match" and "Paddle hit" lines to a header. That will permit an off-screen scoring counter to be added as an option without any modification to the design, implemented however who is making and adding it fancies.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 12:41:00 pm
Continuing with the documentation........... Here is the equivalent diagram of a rather simple section of the game - the Velocity Integrator. The Velocity Integrator provides the complementary potentials, +velocity and -velocity, which are in turn integrated by the Ball Horizontal and Ball Vertical Movement circuits, and thus determine the speed at which the ball moves across the screen.

The potential across the timing capacitor Cv is initially held at 0V courtesy of the (open collector) discharge line. When the ball is served and a match begins the discharge line is released and Cv begins a linear charge towards the positive supply rail. An initial offset potential of approx 0.6V (courtesy of a transistor Vbe-drop in the timing capacitors buffer circuit) provides the initial velocity, or speed at which the ball begins to move the instant it is served.


(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=304397;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 01, 2017, 02:17:37 pm
Equiv. diagram for the Ball Horizontal Movement circuit:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=304420;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 01, 2017, 07:11:32 pm
Might as well mention it; The other night in a fit of immodesty for the first time I tipped a personal project for the Hackaday blog! :D

"Every scrap of it is circuits of his own design, executed dead bug style, apparently because [GK] enjoys life on hard mode."  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 01, 2017, 07:16:57 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

As promised:

(http://timb.us/images/Pad_Sizes.png)

http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf (http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf)
Enlarge all the pads hole to at least 0.8, especially C2.
Enlarge all the pad outer diameters to 1.6, and make C3's pad size 1.8.
Remember, home build PCBs usually are drilled with 1 drill size for as much of the PCB as possible as we may be working with something like a mini Dremel drill press.
For the 1N400x diodes, make the holes 1mm, pads 2mm.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 01, 2017, 08:02:08 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

As promised:

(http://timb.us/images/Pad_Sizes.png)

http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf (http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf)
Thanks Tim, check GK's comments, they somewhat align with mine that your annular rings could be a tad larger.
He suggests 80 mil which is 2 mm. Hole sizing looks great.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 01, 2017, 08:09:11 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

As promised:

(http://timb.us/images/Pad_Sizes.png)

http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf (http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf)
Enlarge all the pads hole to at least 0.8, especially C2.
Enlarge all the pad outer diameters to 1.6, and make C3's pad size 1.8.
Remember, home build PCBs usually are drilled with 1 drill size for as much of the PCB as possible as we may be working with something like a mini Dremel drill press.
For the 1N400x diodes, make the holes 1mm, pads 2mm.
Ummm, I go about it the other way, drill everything at 0.6 mm and then enlarge those that need to be bigger.
I set hole size for everything at 20 mil (0.5 mm) which then helps center the drill bit in the pad, but I use paxolin PCB like GK that is much kinder on bits and you can successfully use HHS bits and not need tungsten.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 01, 2017, 08:34:56 pm
Yes, having a smaller hole does add more copper contact and working with 1 smaller bit is easier.  I agree, 0.6mm would be good, however, if you have a professional PCB made, you can't re-drill these without a mess.  I tried to select a values to make any type of manufacturing choice happy.

On this PCB, only the terminal block connectors and the 1N400x diodes will probably need to be drilled a second time to the larger required size.  The larger electrolytic caps and sip rail as well...  For drill, 0.8mm for the mass majority of everything else should be ok.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 08:42:33 pm
Tim, great work, if you're fussy about layouts they do take some real time.
May I ask what size annular ring size you're using and the pad hole size ?

I've had some pads lift when reworking PCB's and as a result my preference is for larger pads to minimize the chance of this.
When I can I stick with 100 mil and maybe alter the shape from round if more clearances are needed.

As promised:

(http://timb.us/images/Pad_Sizes.png)

http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf (http://timb.us/PDF/Scope_Pong_Pad_Sizes.pdf)
Enlarge all the pads hole to at least 0.8, especially C2.
Enlarge all the pad outer diameters to 1.6, and make C3's pad size 1.8.
Remember, home build PCBs usually are drilled with 1 drill size for as much of the PCB as possible as we may be working with something like a mini Dremel drill press.
For the 1N400x diodes, make the holes 1mm, pads 2mm.

Earlier someone said go with 30mil if I can, 20 mil minimum, so that's what I did. I will enlarge the DO-31 rings as I agree, they're too small.

How about this: What if I did everything 0.75mm/1.5mm, except C3 and D1? I could do those 1mm/2mm. Since a lot of the patterns are already 0.75/1.5mm, I wouldn't have to go back and move most of the stuff I've already put down.

If the extra 0.05mm is that critical, I'll do it, otherwise it would save me a lot of extra work at this point. :)

Edit: By move stuff, I mean that in some areas, I've routed traces just close enough to pads so that it doesn't break the ground pour with the current pad sizes. If I upped all the transistors to 0.8/1.6, I'd have to go back and reroute a lot of stuff. I can do it, I don't mind, but if the 0.05mm isn't *that* critical, I'd rather spend the time routing new sections.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 01, 2017, 09:08:00 pm
You may be fine with all the pads and holes Tim, it's just one of my pet hates, annular rings too small.
I'm somewhat thinking of those that will be buying PCB's or using your files to etch their own PCB. Those that have done some PCB work will have no problem with your work I don't think, moreso those with limited experience taking on this as their first big project. If it's populated without mistake and zero components need to be reworked, then I don't see any problems.
After the effort I know you're putting into this I wouldn't want to see criticism of your efforts by those that have taken on something more complex than they should've.

It's a heap of work Tim, you and GK decide what the outcome should be.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 01, 2017, 09:40:30 pm
You may be fine with all the pads and holes Tim, it's just one of my pet hates, annular rings too small.
I'm somewhat thinking of those that will be buying PCB's or using your files to etch their own PCB. Those that have done some PCB work will have no problem with your work I don't think, moreso those with limited experience taking on this as their first big project. If it's populated without mistake and zero components need to be reworked, then I don't see any problems.
After the effort I know you're putting into this I wouldn't want to see criticism of your efforts by those that have taken on something more complex than they should've.

It's a heap of work Tim, you and GK decide what the outcome should be.

Yeah, I agree with the hate for small annular rings! The diode pattern really needs bigger rings and it's something I forgot to go back and fix. (I copied the DipTrace pattern for the DO-31 package and simply changed the pad spacing without fixing the pad sizes.)

For C2, I had the pad/holes larger, but I felt they were too close together, so made them a bit smaller. In reality, they need to be 0.75/1.5, so I'll go back and fix that. (Lead diameter for the caps is 0.5 +-0.1, so after accounting for hole plating on a professional board, it really needs to be 0.75mm minimum.)

I went with 2mm caps for the 10uF parts as they're at least easy to obtain; 1.5mm is starting to be more common, but the pad spacing would have been absolutely tiny!

I'll make some changes tonight and post another picture of the pad/hole sizes for you guys. I want to do this right, so if 0.8 vs 0.75 will really make a difference, I don't mind going back and changing stuff I've already laid out. Like I said, if the extra 0.05mm isn't that big of a deal, my time could be spent elsewhere. I'll defer to you guys, the much more experienced DIY board makers, on that. ;D

I haven't hand etched and drilled a board in close to 20 years, so I appreciate all the advice and tips from everyone on making this home etchable. I should pickup some supplies and try to etch a few smaller TH boards myself, to get a feel for the process. (The last board I did, I was in my early teens and used a Sharpie and some of those rub down traces and holes, with an etching kit from Radio Shack!)

Edit: When I originally did the patterns, I did it with the intent that most people would buy a professionally made PCB (at $15 for two boards it seems like a bargain), however I made sure the holes were at least 20mil and optimally closer to 30mil, per one of your recommendations. I didn't think about having to change drill bit sizes, so I can see how having as many of the holes as possible one size would be advantageous.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 01, 2017, 11:48:14 pm
Considering the size and number of holes you'd be pretty nuts to home-brew a PCB like this. For something like this, the last thing you need is the additional hassle of tracking down shorts & broken tracks.
It also adds some constraints on the design - e.g. not using top connections to parts that can't be top-side soldered, like multiturn trimmers & connectors.
A PTH board will be a lot more robust, and it's so cheap now, especially as I suspect enough people would be interested to do a small group order, that it's probably not worth going too overboard making the design optimised for homebrew PCBs.
That being said there's never any harm in making track widths & gaps as wide as practical, as this also increases  yield on production boards and improves reworkability. 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 02, 2017, 01:28:04 am
It also adds some constraints on the design - e.g. not using top connections to parts that can't be top-side soldered, like multiturn trimmers & connectors.

These 2 parts in the design are not too terrible a constraint.  It's the reason for making all the other footprint solder-able on both sides and using the TO-92 footprint with the off-center pin #2.

Home etched can be of quality and PCB milling machined boards I can have done locally for 5$, there wont be shorts or breaks, but you still need to solder on both sides.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 02, 2017, 06:41:07 am
Okay boys and girls (if there are any girls), I have finally finished all of the equivalent diagrams and amended circuit diagrams and have collated them into a single 25 page (21 Mb) PDF document. Here it is:

http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf (http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf)

 
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 02, 2017, 07:34:58 am
Okay, so I didn't get nearly as much done as I planned tonight, feeling a bit under the weather so I decided to make an early night of it.

I finished the Function Generator section, but forgot to upload the PDF/images for them, doh!

I also did the Multiplexer FET Gate Drive section; I implemented it as a sub-section of the Multiplexer Logic; the Horizontal and Vertical section will be placed directly above the Multiplexer section. That way the X, Y and Z BNC connectors will all be facing the same side on one board.

I also added some test points and cleaned up some traces in the Multiplexer Logic section.

(http://timb.us/images/Multiplexer_Logic_FET_Drive.png)

http://timb.us/PDF/Scope_Pong_Multiplexer_Logic_FET_Drive.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 02, 2017, 07:48:43 am
Okay boys and girls (if there are any girls), I have finally finished all of the equivalent diagrams and amended circuit diagrams and have collated them into a single 25 page (21 Mb) PDF document. Here it is:

http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf (http://www.glensstuff.com/pong/Oscilloscope_Pong.pdf)

 

Sweet!  Nice work. :)

Considering the size and number of holes you'd be pretty nuts to home-brew a PCB like this. For something like this, the last thing you need is the additional hassle of tracking down shorts & broken tracks.
It also adds some constraints on the design - e.g. not using top connections to parts that can't be top-side soldered, like multiturn trimmers & connectors.
A PTH board will be a lot more robust, and it's so cheap now, especially as I suspect enough people would be interested to do a small group order, that it's probably not worth going too overboard making the design optimised for homebrew PCBs.
That being said there's never any harm in making track widths & gaps as wide as practical, as this also increases  yield on production boards and improves reworkability.

Once I finish the board, my plan was to do a group order that includes the boards and all parts (over 700 of them, per kit) which should significantly bring the price down. Based on the response to my initial inquiries, I think most people will go this route, but there were a few people who wanted to etch their own boards, so I'm trying to to at least make it possible. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: dr_dan on April 02, 2017, 08:56:27 am

First of all can I say what a great thread this is. I always follow GK's projects, and this time around I should be able to build it too thanks to the group effort here.

I've been thinking (a little) about the discussion on adding scorekeeping to the game.
I like GK's all discrete analog construction, so I'm in the camp that thinks 7 segment displays or LEDs would be out of place here.

So, we already have a scope as the court, how about using a meter or two to display the score? Let's bring more test equipment into the game!

Some possibilities:

Two volt meters, one per player, 1v per point.

A volt meter that reads +ve or -ve depending on the player, 1v per point. Would show the running points difference.

One volt meter, but with different voltage increments per player, so for example 3.5v would be a score of 3 to 5.

Exchange volt meters for frequency counters or totalisers?


I'll defer to GK to assess the complexity, but hopefully the two volt meter option would be straightforward - perhaps just a couple of integrators?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 02, 2017, 09:51:05 am
Thinking about how you could add an option connector to add onscreen scoring.
If the design just included some dead-time in the display cycle, and a way to switch the outputs to the option connector during that time, that would allow for an external renderer. The switch-over/mux could be on the option board, and jumpered out when not fitted.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 02, 2017, 10:55:40 am
I like GK's all discrete analog construction, so I'm in the camp that thinks 7 segment displays or LEDs would be out of place here.

Well, LEDs are still discrete. You could even make a 7-segment display with discrete LEDs if you really wanted (though I think some of those little HP bubble 7-segment displays wouldn't look out of place, and they *are* period appropriate).

It isn't all analog, either. Sure, the graphics are drawn though a combination of sine, cosine, triangle and square waves generated by discrete integrators and op-amps, but that's not the end of the story... It's also full of discrete digital components as well; flip-flops, logic gates, inverters and  latches! There are also comparators, which are half-digital (kind of). In fact, I'd say at least half of the circuits are digital in nature.

So, personally, I don't see where a discrete counter circuit that outputs to a period appropriate LED display would be out of place. In fact, I think it could kind of balance out the "other side" of the underlying circuits. That is, you'd have an analog (the scope) and digital (the LEDs) output for a project that's already both analog and digital!

Just my two cents, anyway.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 02, 2017, 11:13:23 am
Okay, so I didn't get nearly as much done as I planned tonight, feeling a bit under the weather so I decided to make an early night of it.

I finished the Function Generator section, but forgot to upload the PDF/images for them, doh!

I also did the Multiplexer FET Gate Drive section; I implemented it as a sub-section of the Multiplexer Logic; the Horizontal and Vertical section will be placed directly above the Multiplexer section. That way the X, Y and Z BNC connectors will all be facing the same side on one board.

I also added some test points and cleaned up some traces in the Multiplexer Logic section.



Hi Tim. You're making some good progress, but there are some important layout points I should probably interject here with. In the gate drive circuit there is associated with each JFET pair a 20k resistor terminating the gate terminals to ground and a commutation diode. In your schematic these are R1101, R1105, R1109, R1113, D1101, D1102, D1103 and D1104.

When a JFET pair is turned ON its respective commutation diode is reverse biased and the gates are effectively isolated and terminated to ground through the respective 20k resistor. We don't want this termination resistor to be half a board width away with a long inductive track in between. And although the discrete op-amps in the horizontal and vertical deflection circuit do not have a super high GBWP, it is still good practice to minimize the virtual earth nets.

These requirement make it necessary to bunch up to some degree the JFETs and their associated gate diodes and resistors around the inverting inputs of the respective op-amps. Attached is a scribble of a quick/rough diagram approximating an acceptable layout that meets these requirements.   

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=304624;image)


The length of the logic-level digital control lines emanating from the cathodes of the gate commutation diodes really doesn't matter; it's just these components that you have to keep reasonably compact.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 02, 2017, 02:06:22 pm
In addition to the above I should have also mentioned that the input resistors which connect directly to the JFET drains should be placed as close to the JFETs as practical.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: dr_dan on April 02, 2017, 03:00:55 pm
It isn't all analog, either. Sure, the graphics are drawn though a combination of sine, cosine, triangle and square waves generated by discrete integrators and op-amps, but that's not the end of the story... It's also full of discrete digital components as well; flip-flops, logic gates, inverters and  latches! There are also comparators, which are half-digital (kind of). In fact, I'd say at least half of the circuits are digital in nature.

True of course. What I meant was that the whole circuit is built only from discrete analog components - some are indeed built into sub-circuits that form the basic digital building blocks you mention - but there are no logic gate ICs in there, and for me that really adds to the charm of the project.

Now, if you go and add a 7-seg driver built out of discrete transistors that could be interesting...  :)



Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 02, 2017, 04:27:45 pm
Quote from: dr_dan
Now, if you go and add a 7-seg driver built out of discrete transistors that could be interesting...  :)
Not that hard - 1 of 10 counter and a diode matrix to decode.
Maybe use multiplexing to share the diode array between digits. Single digit per player would keep things more sensible.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: SeanB on April 02, 2017, 05:19:41 pm
Diodes are cheap, just use one set per digit, you only need 44 per digit to fully decode 0-9, and 10 driver transistors to provide segment current.

Now, use that to drive a sexedecimal display and multiplexing would be worthwhile to share the decode logic between them.

Challenge is to have a on screen display with player names.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 02, 2017, 06:06:19 pm

Challenge is to have a on screen display with player names.
.. with international character set, including Chinese,Thai,Arabic,Hebrew etc...
Core rope memory perhaps.....
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 02, 2017, 07:28:13 pm
Okay, so I didn't get nearly as much done as I planned tonight, feeling a bit under the weather so I decided to make an early night of it.

I finished the Function Generator section, but forgot to upload the PDF/images for them, doh!

I also did the Multiplexer FET Gate Drive section; I implemented it as a sub-section of the Multiplexer Logic; the Horizontal and Vertical section will be placed directly above the Multiplexer section. That way the X, Y and Z BNC connectors will all be facing the same side on one board.

I also added some test points and cleaned up some traces in the Multiplexer Logic section.



Hi Tim. You're making some good progress, but there are some important layout points I should probably interject here with. In the gate drive circuit there is associated with each JFET pair a 20k resistor terminating the gate terminals to ground and a commutation diode. In your schematic these are R1101, R1105, R1109, R1113, D1101, D1102, D1103 and D1104.

When a JFET pair is turned ON its respective commutation diode is reverse biased and the gates are effectively isolated and terminated to ground through the respective 20k resistor. We don't want this termination resistor to be half a board width away with a long inductive track in between. And although the discrete op-amps in the horizontal and vertical deflection circuit do not have a super high GBWP, it is still good practice to minimize the virtual earth nets.

These requirement make it necessary to bunch up to some degree the JFETs and their associated gate diodes and resistors around the inverting inputs of the respective op-amps. Attached is a scribble of a quick/rough diagram approximating an acceptable layout that meets these requirements.   

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=304624;image)


The length of the logic-level digital control lines emanating from the cathodes of the gate commutation diodes really doesn't matter; it's just these components that you have to keep reasonably compact.

Okay, good to know. My plan was to start building out the H and V circuit literally right from where the Gate Drive circuit currently is, so the GATE0-3 nets won't be routed more than an inch or so. Basically I'm making the Multiplexing Logic, FET Gate Drive and H&V Deflection circuits one single super-section as far as the layout is concerned, if that makes any sense? I figure that would best preserve signal integrity and make the layout most compact.

Edit: Though I will most likely move those gate diodes and resistors so that they're as close as I can get them to the associated JFET pair. Ultimately there will need to be at least a couple of inches of trace coming from the anode of the gate diode, since they split between the Horizontal and Vertical JFETs, which I can't easily mix since their outputs have to stay together to keep the the two virtual GNDs short. That said, they won't be running hundreds of mm across the board or anything.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 02, 2017, 11:47:59 pm
Quote
Edit: Though I will most likely move those gate diodes and resistors so that they're as close as I can get them to the associated JFET pair. Ultimately there will need to be at least a couple of inches of trace coming from the anode of the gate diode, since they split between the Horizontal and Vertical JFETs, which I can't easily mix since their outputs have to stay together to keep the the two virtual GNDs short. That said, they won't be running hundreds of mm across the board or anything.


That sounds fine.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 03, 2017, 03:22:07 am
Well, LEDs are still discrete. You could even make a 7-segment display with discrete LEDs if you really wanted (though I think some of those little HP bubble 7-segment displays wouldn't look out of place, and they *are* period appropriate).

IIRC, GK's original suggestion was to use discrete LEDs to make the 7-segment display (i.e., it's a 7-segment display in name, but each segment is comprised of discrete LEDs).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 03, 2017, 10:54:25 am
Quote
Edit: Though I will most likely move those gate diodes and resistors so that they're as close as I can get them to the associated JFET pair. Ultimately there will need to be at least a couple of inches of trace coming from the anode of the gate diode, since they split between the Horizontal and Vertical JFETs, which I can't easily mix since their outputs have to stay together to keep the the two virtual GNDs short. That said, they won't be running hundreds of mm across the board or anything.


That sounds fine.

Something like this?

(http://timb.us/images/XYZ_1.png)
(http://timb.us/images/XYZ_2.png)
(http://timb.us/images/XYZ_3.png)
(Note: The board in those pictures is sized just big enough for that circuit, it's not the size of the final board and will be bigger.)

http://timb.us/PDF/Scope_Pong_XYZ.pdf

There's a couple of things in still not totally happy with and will go back to fix, but it's where I'm at tonight. So, the gate diode and resistor is right next to one of the JFETs and no more than 20mm from the other. Hopefully that will suffice?

I'm not happy with how long common lines that feed from all the JFETs to each deflection amplifier are, but it's the best I can do for right now. I may have a way to shave about 20mm off each, so I'll try that out later today.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 03, 2017, 12:30:40 pm
OK, I can see what you've done there in an attempt to minimise the track length between the gate leads of each JFET pair, but really an inch or two of track length here won't hurt. What I was trying to emphasize in my prior post is that the JFET digital control lines on the anode side of the commutation diodes actually become sensitive analogue lines, so it's just important not to route them over long distances amongst other circuitry such as the digital stuff.

I don't think that your layout would cause any problems, but I'd personally rotate the JFETs 90 degrees and position them in a row as shown in my scribbled diagram, with the gate control lines running parallel to the in-line JFETs. I think this would permit a more optimal minimisation of the virtual earth nets whilst still keeping the gate nets adequately short and well confined to the analogue zone. Incidentally the way I laid out my rats nest version was as per that scribbled layout.
 

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 03, 2017, 01:07:17 pm
OK, I can see what you've done there in an attempt to minimise the track length between the gate leads of each JFET pair, but really an inch or two of track length here won't hurt. What I was trying to emphasize in my prior post is that the JFET digital control lines on the anode side of the commutation diodes actually become sensitive analogue lines, so it's just important not to route them over long distances amongst other circuitry such as the digital stuff.

I don't think that your layout would cause any problems, but I'd personally rotate the JFETs 90 degrees and position them in a row as shown in my scribbled diagram, with the gate control lines running parallel to the in-line JFETs. I think this would permit a more optimal minimisation of the virtual earth nets whilst still keeping the gate nets adequately short and well confined to the analogue zone. Incidentally the way I laid out my rats nest version was as per that scribbled layout.
 

Yeah, rotating the JFETs is preciously what I was thinking of doing. I'll give that a shot tonight.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 04, 2017, 02:25:22 am
It's still a bit of a work in progress, but I thought I'd share where I'm at:

(http://timb.us/images/XYZ_V2_1.png)
(http://timb.us/images/XYZ_V2_2.png)
(http://timb.us/images/XYZ_V2_3.png)

http://timb.us/PDF/Scope_Pong_XYZ_V2.pdf

So the virtual GND net is a lot shorter, but the lines from the adjustment pot lines are a lot longer than before, which I'm currently working on shortening a bit. This new layout does give me about 1/4 more useable space than the previous version, so that's a plus.

I couldn't follow your recommended layout exactly, because the pinout of the SMD JFET is different than the TH version, so I had to make a few small orientation changes, but I think it's still better than before.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 04, 2017, 02:44:35 am
Nice...
Increase the outer diameter of the pads for the Z-Axis Inv select 3 pin sip, the rings are too thin.
Everything else is excellent.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 04, 2017, 03:00:53 am
Nice...
Increase the outer diameter of the pads for the Z-Axis Inv select 3 pin sip, the rings are too thin.
Everything else is excellent.

Oops, yeah, thanks for reminding me! I've been meaning to go back and fix that. (That's just a DipTrace built-in 1x3 Header pattern I used when making the Z-Select change to the schematic, I intended to go back and make a custom pattern with bigger rings.) Added to my to-do list!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 04, 2017, 03:53:40 am
I couldn't follow your recommended layout exactly, because the pinout of the SMD JFET is different than the TH version, so I had to make a few small orientation changes, but I think it's still better than before.


Keep in mind though that the virtual earth nodes extend to the drain side nets of the JFETs.

You can do my suggested layout like this:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=305223;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 04, 2017, 04:02:55 am
For the center of that matrix, keeping the j-fet on the red layer, swap the blue and red trace layers inbetween, you will save on removing 1/2 the vias.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 04, 2017, 06:27:56 am
Okay, let me give that a try. I initially had something similar to that, but ended up changing it for some reason that I can't recall. I obviously overlooked something. (Man, I'll be glad when I get over this cold, or sinuses or whatever it is. My head feels like it's been in a vice for the last two nights and I just can't focus.)

Once I get that fixed up, I might go back and start routing some of the power and signal nets to the board to board connectors and do the power supply layout, which is fairly simple. Hopefully in a day or two I'll be feeling better and can finish the rest of the blocks. I've just got Horizontal and Vertical Ball, Paddle and Sound circuits left.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 04, 2017, 07:05:05 am
After staring at the layout for 15 minutes I totally see how I could have made that work; I don't know how I missed it. I just need to rotate a few things and twist something around. I can't believe I forgot both sides of the JFET are in the virtual ground. I mean it's a JFET, duh! :palm:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 04, 2017, 07:38:17 am
Keep well and get some early nights Tim, that's more important than getting it finished, yeah I know you have lots of us watching your progress (1) but it can wait.

1. 1125 guests watching.  :o

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 04, 2017, 08:49:18 am
Ha ha. These things inevitably happen after X amount of free-time hours successively crammed into one task without a break.... I wasted an hour or more debugging an entirely nonexistent fault with those JFET-multiplexed deflection amplifiers after I first built them. I was at one stage utterly baffled, then convinced that my JFETs were dodgy counterfeits as they all seemed to exhibit a decaying Id current tail at switch-off that seemed to defy JFET semiconductor physics...... but some spare SOT-23 MMBF**** soldered in to substitute behaved just the same....  In the end it turned out that my 10:1 CRO probe just wasn't properly compensated!  :palm:


BTW, has anyone else noticed the crazy number of views this thread has had today? First thing this morning the topic view counter had not yet clocked over 10,000. Now, about 12 hours later, it's close to tripping past 15600! :o I don't think this amount of traffic can be still coming from the Hackaday blog, as the mention is several-days-old news now and has scrolled well off the main page.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=305312;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 04, 2017, 08:55:54 am
 :-DD
Probe compensation sanity check.  :phew:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 04, 2017, 10:42:17 am
Keep well and get some early nights Tim, that's more important than getting it finished, yeah I know you have lots of us watching your progress (1) but it can wait.

1. 1125 guests watching.  :o

I'm hoping it's just allergies, as there was a nice layer of pollen on my windshield today. The weather has also been crazy, freezing one day and cold the next, which never helps.

Ha ha. These things inevitably happen after X amount of free-time hours successively crammed into one task without a break.... I wasted an hour or more debugging an entirely nonexistent fault with those JFET-multiplexed deflection amplifiers after I first built them. I was at one stage utterly baffled, then convinced that my JFETs were dodgy counterfeits as they all seemed to exhibit a decaying Id current tail at switch-off that seemed to defy JFET semiconductor physics...... but some spare SOT-23 MMBF**** soldered in to substitute behaved just the same....  In the end it turned out that my 10:1 CRO probe just wasn't properly compensated!  :palm:

Ah, the old probe compensation trap... I think we've all run into that before! XD

I really should take more breaks than I do (and I try to), but sometimes I'll sit down at 8pm and start working, the next thing I know it's midnight! And the only reason I even stop then is because my dog starts bugging me to eat. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: krivx on April 04, 2017, 02:20:57 pm

BTW, has anyone else noticed the crazy number of views this thread has had today? First thing this morning the topic view counter had not yet clocked over 10,000. Now, about 12 hours later, it's close to tripping past 15600! :o I don't think this amount of traffic can be still coming from the Hackaday blog, as the mention is several-days-old news now and has scrolled well off the main page.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=305312;image)

It's on the front page of Hacker News right now.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: AndyC_772 on April 05, 2017, 08:00:34 am
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 05, 2017, 09:37:50 am
And who is Brian?


LOL, I have no idea.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 05, 2017, 11:35:44 am
I couldn't follow your recommended layout exactly, because the pinout of the SMD JFET is different than the TH version, so I had to make a few small orientation changes, but I think it's still better than before.


Keep in mind though that the virtual earth nodes extend to the drain side nets of the JFETs.

You can do my suggested layout like this:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=305223;image)

Okay, so here's what I came up with:

(http://timb.us/images/XYZ_V3.png)

http://timb.us/PDF/Scope_Pong_XYZ_V3.pdf

I shifted the diodes around a bit to save space, but I still kept it very compact and the lines running to the drain nodes of the JFETs are each around 20mm. I still need to place the trimmers (ignore them in the image), but so far so good I think.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 05, 2017, 11:58:55 am
but so far so good I think.


 :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 05, 2017, 06:18:27 pm
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)

Congrats, GK!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 05, 2017, 06:24:08 pm
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)

Wow!

With all this interest, it makes me wonder how many kits one could sell for this ?
(Being practical it would be very limited, as how many people have access to a suitable scope, too few I imagine).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 05, 2017, 06:31:21 pm
It's also a non-trivial amount of soldering. But, hey, you don't have to build it all in a single weekend.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 05, 2017, 06:38:52 pm
It's also a non-trivial amount of soldering. But, hey, you don't have to build it all in a single weekend.

In the 1970's, when Pong (Electronic TV Table tennis) projects?/Kits?/Designs? (I'm not sure of the exact source, but it was probably electronics magazines) were popular, some electronics hobbyists/enthusiasts would build their own, out of something like a 100 or hundreds of TTL/CMOS? (probably TTL) integrated circuits. Not a microprocessor or complex IC in sight.
The PCB's were huge, like two feet square (from memory).

They were great fun to play at the time.

Later I think there were single IC versions available, and later still ones with switchable multiple games, built in. Such as Football/Squash etc. Eventually tank attack games, if I remember correctly, and colour versions.

I hear/believe these days, all the transistors need to be pre-soldered apart from one transistor, one resistor and nothing else as the attention span would be exceeded. Then they built it all themselves  ::)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 05, 2017, 06:56:43 pm
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)

Wow!

With all this interest, it makes me wonder how many kits one could sell for this ?
(Being practical it would be very limited, as how many people have access to a suitable scope, too few I imagine).
I'd use this project as a measure of how good a digital scope in X/Y mode can emulate a real analog scope.
Basically it will be one of my test bench marks when purchasing my next digital scope.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 05, 2017, 07:00:59 pm
Okay, so here's what I came up with:

http://timb.us/PDF/Scope_Pong_XYZ_V3.pdf (http://timb.us/PDF/Scope_Pong_XYZ_V3.pdf)

I shifted the diodes around a bit to save space, but I still kept it very compact and the lines running to the drain nodes of the JFETs are each around 20mm. I still need to place the trimmers (ignore them in the image), but so far so good I think.
Perfect.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mmagin on April 05, 2017, 07:01:18 pm
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)

Wow!

With all this interest, it makes me wonder how many kits one could sell for this ?
(Being practical it would be very limited, as how many people have access to a suitable scope, too few I imagine).
I'd use this project as a measure of how good a digital scope in X/Y mode can emulate a real analog scope.
Basically it will be one of my test bench marks when purchasing my next digital scope.

Probably cheaper to just own multiple scopes :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 05, 2017, 07:47:49 pm
Yeah, I'll have to fix the focus on my old CRO for this. :-BROKE
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 05, 2017, 08:48:40 pm
It's made The Register too:

https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/ (https://www.theregister.co.uk/2017/04/05/oscilloscope_pong/)

Wow!

With all this interest, it makes me wonder how many kits one could sell for this ?
(Being practical it would be very limited, as how many people have access to a suitable scope, too few I imagine).
I'd use this project as a measure of how good a digital scope in X/Y mode can emulate a real analog scope.
Basically it will be one of my test bench marks when purchasing my next digital scope.
Digital scopes do vary somewhat in their X/Y behaviour. Not all have Z inputs. The RTB2004 has, AFAIK uniquely, an XYY mode, which will show two XY traces in different colours. It may be that there are a few true dual-gun CRT scopes that can do this ( obviously not in different colours) .
If the output bandwidth is within the audio range, it would be useful to record the output to a WAV file so people can test on different scopes.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 05, 2017, 09:36:28 pm
Okay, so here's what I came up with:

http://timb.us/PDF/Scope_Pong_XYZ_V3.pdf (http://timb.us/PDF/Scope_Pong_XYZ_V3.pdf)

I shifted the diodes around a bit to save space, but I still kept it very compact and the lines running to the drain nodes of the JFETs are each around 20mm. I still need to place the trimmers (ignore them in the image), but so far so good I think.
Perfect.

I also fixed the Z-Select header pads since that PDF. Hole size is 1.1 and pad size is 2.2.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 05, 2017, 10:35:16 pm
Digital scopes do vary somewhat in their X/Y behaviour. Not all have Z inputs. The RTB2004 has, AFAIK uniquely, an XYY mode, which will show two XY traces in different colours. It may be that there are a few true dual-gun CRT scopes that can do this ( obviously not in different colours) .
If the output bandwidth is within the audio range, it would be useful to record the output to a WAV file so people can test on different scopes.
Hmmm, a 192khz 16bit stereo sample.  Unfortunately, DC coupling will be lost, but, maybe with a flat down to 1Hz system, you can still generate a valid test sample.  Probably saving it in a FLAC format will super compress it because of the repeating nature of the signal.  Any other lossy audio format would make a mess of things.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on April 05, 2017, 10:51:27 pm
For testing how good a digital scope might display it, you could use the YouScope demo:

https://www.youtube.com/watch?v=OxlCoKN4W7c (https://www.youtube.com/watch?v=OxlCoKN4W7c)

It looks quite good on a million waveforms per second update Agilent scope with some persistence tricks to remove the flyback traces, as Dave shows in the video, but really crap on less good digital scopes. Lossless FLAC file: http://kapsi.fi/~jpa/stuff/other/youscope-wave.flac (http://kapsi.fi/~jpa/stuff/other/youscope-wave.flac)

With the z-signal the Agilent scope might be really good for the pong game.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 05, 2017, 11:24:19 pm
Very hard to predict demand for something like this but my guess is "more than you'd think".
A kit might be a candidate for Tindie or Crowdsupply, maybe even Kickstarter.
But one issue is you don't want to be saddled with supporting people who can't solder.
It would be nice to be able to leverage the savings from buying PCBs and parts in quantity, especially if you could find a supplier to kit up the parts.

Speaking of supply etc., has any effort yet been put into BOM minmisation?

One other comment re. ease of assembly - it would be nice if all diodes withing a local group were the same way round -  a bit if a fiddle for PCB layout but could reduce risk of errors quite a bit. Ditto polarised caps.
 


Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on April 06, 2017, 07:18:32 am
Organizing the kits, shipping, customer communication etc. is always a lot of work in my experience with my C64 Kerberos cartridge. The easiest way might be to contact a manufacturer like Evil Mad Scientist, who sell the 555 kit:

http://shop.evilmadscientist.com/productsmenu/652 (http://shop.evilmadscientist.com/productsmenu/652)

and ask them, if they want to sell a pong kit. Then you can sell them the PCB layout for a good one time price. Maybe less profit than when you do it yourself, but no risk and no tedious manufacturing and shipping work, but still everyone can buy the kit.

If you want to sell it yourself, iteadstudio has an assembly service,  for fully populated boards, which some people might prefer:

http://support.iteadstudio.com/support/solutions/folders/1000212715 (http://support.iteadstudio.com/support/solutions/folders/1000212715)

They say up to 25 boards, but maybe they can help you find a cheap service for larger quantities as well. Their boards are very good and cheap, so I guess their assembly service has the same quality. Maybe get a quote from them for 25 of your boards, then create a Kickstarter project with minimum funding required to pay the 25 boards (with a good factor like 3x for all the work etc.), no risk. Judging by the media echo, it should be no problem to sell 25 boards. And of course, some people, like me, would like to buy a kit, so this should be another Kickstarter reward.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 11:55:29 am
Organizing the kits, shipping, customer communication etc. is always a lot of work in my experience with my C64 Kerberos cartridge. The easiest way might be to contact a manufacturer like Evil Mad Scientist, who sell the 555 kit:

http://shop.evilmadscientist.com/productsmenu/652 (http://shop.evilmadscientist.com/productsmenu/652)

and ask them, if they want to sell a pong kit. Then you can sell them the PCB layout for a good one time price. Maybe less profit than when you do it yourself, but no risk and no tedious manufacturing and shipping work, but still everyone can buy the kit.

If you want to sell it yourself, iteadstudio has an assembly service,  for fully populated boards, which some people might prefer:

http://support.iteadstudio.com/support/solutions/folders/1000212715 (http://support.iteadstudio.com/support/solutions/folders/1000212715)

They say up to 25 boards, but maybe they can help you find a cheap service for larger quantities as well. Their boards are very good and cheap, so I guess their assembly service has the same quality. Maybe get a quote from them for 25 of your boards, then create a Kickstarter project with minimum funding required to pay the 25 boards (with a good factor like 3x for all the work etc.), no risk. Judging by the media echo, it should be no problem to sell 25 boards. And of course, some people, like me, would like to buy a kit, so this should be another Kickstarter reward.

It's an interesting thought, but I think we should see how the initial kits do here first. If there's more interest outside of the forums it'll totally be up to GK if he's OK with it being sold in some commercial fashion or not. (I only got GK's blessing to produce and sell a run of kits and/or boards to forum members.) Now, if it did turn out to be amazingly popular and there was a ton of demand outside the forum, I'd be more than happy to work out something so he gets paid royalties on any kit sales or something, but like I said, it's up to him where this goes and if it gets sold outside the forum at all.

As for assembled versions, it would be pretty expensive to have them assembled, due to it being all through hole, combined with the size of the boards. Most assembly houses (at least the ones I know of here in the US and China) don't have equipment for automated insertion of Th parts, and if they do it's only for large runs. Instead, they have people manually stuff the boards, which is fine when you're dealing with one or two TH parts on an otherwise SMD board, but not over 700!

Now, all the parts are available in surface mount variations, which would allow automated assembly *and* would cut the board size down by 2/3. That said, I don't see the point myself. I mean, half the fun in something like this is actually soldering the thing, plus the whole retro look and feel!

At any rate, like I said earlier, let's see how the basic kit does here, first. :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 12:09:46 pm
Tonight I got the power supply section done:

(http://timb.us/images/Power.png)

http://timb.us/PDF/Scope_Pong_Power.pdf

Each +15V and -15V rail sub-section (that includes the TO-220 Darlington, heatsink, Zener, support passives, adjustment pot and two 2N390x transistors) takes up only slightly more space than a *single* TO-3 transistor, so it's basically the same size (board wise) as GK's original circuit. My circuit includes improved regulation, adjustable output voltage (the adjust pot can be jumpered and the top fixed value resistor increased to ~12K if adjustment is not needed), improved regulation (about 50mV over line and load) and lower ripped (less than 5mV at full load, 500uV at 1/4 load).

It'll do 500mA easily and has a current limit of 800mA. I wanted to make sure it could do the added current to handle a potential scoring add-on board someone may make.

I've used a similar circuit on another board in the past and it works great. I've also tested this exact circuit and it seems to work perfectly. It's not *that* much more complex than the original power supply, but provides some nice benefits. If you guys don't like it, I can always make the power board modular and provide two options, one for the original TO-3 design and one for mine.

Here's the updated schematic:

http://timb.us/PDF/Scope_Pong_20170406.pdf

Edit: Fixed link to schematic.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 06, 2017, 12:14:17 pm
For something this niche I don't think it would be worth offering more than two things - PCB only, and full kit.
As soon as you start looking at assembly, there's a much bigger committment and work needed.
Even a SMD version would be fairly expensive to assemble due to the high component count, and SMD would probably detract from some of the retro-ness.
I'd say it would definitely be worth talking to EMSL - they are nice people - they may or may not be interested in carrying it themselves, but may at least have some useful advice.

If you do want to persue it as a product I definitely think  it would be good to somehow get it on display at Bay Area Maker Faire.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 06, 2017, 12:18:23 pm
Tonight I got the power supply section done:
Would be worth making sure there's space to mount the caps horizontally , and have holes for securing wires/cableties as these will be the tallest parts.( Maybe also the voltage regs?)
I'd also suggest you include a polyfuse on the input for safety.
Maybe also a PCB-mounted on/off switch.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 12:27:34 pm
Tonight I got the power supply section done:
Would be worth making sure there's space to mount the caps horizontally , and have holes for securing wires/cableties as these will be the tallest parts.( Maybe also the voltage regs?)
I'd also suggest you include a polyfuse on the input for safety.
Maybe also a PCB-mounted on/off switch.

Ah yes, good idea on horizontal area for the caps. These are 16x32.5mm (7.5mm lead spacing) caps, so it'll use quite a bit of space to do them horizontal, but where I plan on placing this section there should be room. I'll squeeze in space for cable tie holes.

Originally I was actually going to put in a polyfuse, but couldn't decide on if it was really needed or not. I don't suppose there would be any issue placing it on the AC side of the rectifier? (It just occurs to me I've never seen them rated in anything but VDC, but I can't think of any reason why it wouldn't work, so long as the rating is above the peak AC voltage.)

I figured the user would route either the 120/240VAC through a panel mount switch before going into the transformer, though I could add a DPST switch between the terminal block and rectifier for good measure. (The user can always jumper it if they don't need it I guess.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 06, 2017, 12:54:53 pm
Originally I was actually going to put in a polyfuse, but couldn't decide on if it was really needed or not. I don't suppose there would be any issue placing it on the AC side of the rectifier? (It just occurs to me I've never seen them rated in anything but VDC, but I can't think of any reason why it wouldn't work, so long as the rating is above the peak AC voltage.)
I think it is important, as someone may use a big-ass transformer they just happen to have available, which could make a lot of smoke.
BTW you appear to have forgotten a centre-tap connection for the transformer. Obviously you need 2 PFs.
May also be worth adding a footprint (connector or links) for DC-in, in case someone already has a suitable supply.

Quote

I figured the user would route either the 120/240VAC through a panel mount switch before going into the transformer, though I could add a DPST switch between the terminal block and rectifier for good measure. (The user can always jumper it if they don't need it I guess.)
I'm thinking if someone has an already-cased transformer, it may be convenient to have a local switch.

220R for a red LED on 15v is way too low. Should be more like 1K

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 06, 2017, 01:16:11 pm
Hmmm, those little TO-220 heatsinks probably have a thermal resistance in the vicinity of 25-30 deg.C/W. The positive rail one will be sweltering at around 80 deg.C at a minimum at room temp. given the current consumption of the positive rail, not counting the possible additional drain of an add-on scoring unit. 800mA will melt some silicon.

15VAC rather than 18VAC input will give you enough regulator headroom with adequate filtering after rectification, and about half the power dissipation.

The trimmer potentiometers for adjusting the regulator output voltages should be shifted to the feedback resistor leg between the control transistors base and ground. That way if the trimmers wiper goes open circuit the rail voltage will collapse to around 7V, rather than go in the opposite direction and saturate close to the unregulated input potential.
 
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 01:54:01 pm
Hmmm, those little TO-220 heatsinks probably have a thermal resistance in the vicinity of 25-30 deg.C/W. The positive rail one will be sweltering at around 80 deg.C at a minimum at room temp. given the current consumption of the positive rail, not counting the possible additional drain of an add-on scoring unit. 800mA will melt some silicon.

15VAC rather than 18VAC input will give you enough regulator headroom with adequate filtering after rectification, and about half the power dissipation.

The trimmer potentiometers for adjusting the regulator output voltages should be shifted to the feedback resistor leg between the control transistors base and ground. That way if the trimmers wiper goes open circuit the rail voltage will collapse to around 7V, rather than go in the opposite direction and saturate close to the unregulated input potential.

Those heatsinks are surprisingly good, much better than the crappy stamped metal ones you normally see.  I tested it pulling about 300mA and case temperature got up to about 70c, that's with a 18VDC input.

Edit: These heatsinks have solder pins, so I've got them hooked to the ground plane to increase thermal dissipation.

An 18Vct transformer is the maximum I would recommend, but it would work best with a 15Vct transformer, yes. (In fact, on the layout PDF that should have said "18-0-18 Max Input, 15-0-15 Min Input" but I forgot to change it.

Current limit can be lowered by simply increasing the 1ohm resistor to 1.5 or 2 ohms. Though, the idea is to more or less prevent a dead short from immediately blowing the power transistor, rather than protecting it during a sustained fault. I may have a simple method of implementing snap back current limiting, but I'm not sure it's worth it overall.

Good catch on the trimmer; that's the way I originally had it wired up on the breadboard.

I think it is important, as someone may use a big-ass transformer they just happen to have available, which could make a lot of smoke.
BTW you appear to have forgotten a centre-tap connection for the transformer. Obviously you need 2 PFs.
May also be worth adding a footprint (connector or links) for DC-in, in case someone already has a suitable supply.

Okay, Polyfuse it is. Good catch on the center tap! I can't believe I forgot that... I'll switch the connector over to a 3-way.

I figured the user could just push +-18VDC in through the regular AC input, but if you think it would be worthwhile, I'll make provisions.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on April 06, 2017, 04:46:05 pm
Okay, Polyfuse it is.

I would like to have good old glass fuses. With fuse holders, in case someone blows it up. AC side would be best, then it would trip too if the rectifier shorts.

(http://www.futurlec.com/Pictures/Fuse_Holder_6x30.jpg)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 07:02:59 pm
Okay, Polyfuse it is.

I would like to have good old glass fuses. With fuse holders, in case someone blows it up. AC side would be best, then it would trip too if the rectifier shorts.

(http://www.futurlec.com/Pictures/Fuse_Holder_6x30.jpg)

Keep in mind the user would likely (at least they *should*) already have a chassis mount fuse holder installed on the mains side of the transformer. (That protects you in case of a transformer short as well.)

I thought of putting down a glass fuse on the board as well, post transformer, but can't think of any advantages compared to a polyfuse. (They take up a lot of space too.)

I'm thinking, if someone really wanted a glass fuse on the low voltage side of the transformer they could always just use a chassis mount one. However, if you guys would really prefer that over a polyfuse, I *can* do it on the board, though I'd rather not. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on April 06, 2017, 08:17:10 pm
I thought a polyfuse is too modern. Looks like commercial polyfuses were available after 1981. Every other part so far was available before I was born :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 06, 2017, 08:57:17 pm
I thought a polyfuse is too modern. Looks like commercial polyfuses were available after 1981. Every other part so far was available before I was born :)

There were resetable fuses before 1981, using magnetic, thermal and maybe other methods. So it was sort of possible.
Some early AVO multimeters had a cut-out button, using that method.
The Polyfuse adds the concept of "automatically reseting", once it cools down, but otherwise is similar.

I see it more as swapping metal canned Germanium transistors for Black plastic Silicon transistors, than a bad breach of replicas.

But strictly speaking, you are right, they weren't (in that form), available in the old days (1970s).
Unless there were thermistor equivalents ?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 06, 2017, 10:37:02 pm
Tonight I got the power supply section done:

(http://timb.us/images/Power.png)


Don't forget the V+&- test points by the trim-pots.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 06, 2017, 10:41:31 pm
Speaking of supply etc., has any effort yet been put into BOM minmisation?
Do you mean the last 2 pages on timb's schematic here:
Here's the updated schematic:

http://timb.us/PDF/Scope_Pong_20170406.pdf (http://timb.us/PDF/Scope_Pong_20170406.pdf)

Edit: Fixed link to schematic.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 10:53:04 pm
Speaking of supply etc., has any effort yet been put into BOM minmisation?
Do you mean the last 2 pages on timb's schematic here:
Here's the updated schematic:

http://timb.us/PDF/Scope_Pong_20170406.pdf (http://timb.us/PDF/Scope_Pong_20170406.pdf)

Edit: Fixed link to schematic.

BOM minimization means trimming unneeded components or replacing them with components already on the BOM. (I.e., if your BOM has, say, ten 100k resistors and one 200k resistor, you could replace the 200k part with two 100k parts, that way you don't need another BOM item, stuff like that.)

To answer Mike's question: No, not yet. That's generally something I don't do on a first pass anyway.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 06, 2017, 10:55:59 pm
Speaking of supply etc., has any effort yet been put into BOM minmisation?
Do you mean the last 2 pages on timb's schematic here:
Here's the updated schematic:

http://timb.us/PDF/Scope_Pong_20170406.pdf (http://timb.us/PDF/Scope_Pong_20170406.pdf)

Edit: Fixed link to schematic.

Seems like there may be some scope for optimisation - just looking at the BOM list
33 different resistor values
100uf 16v and 25v
two different types of 10u 25V
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 10:56:06 pm
Tonight I got the power supply section done:

(http://timb.us/images/Power.png)


Don't forget the V+&- test points by the trim-pots.

Yeah, I've got that on my list of things to add to the power supply section tonight, along with fixing the trim pot connections, adding a connection to the transformer center tap, adding polyfuses, adding additional decoupling caps around the entire board, looking into an on-off switch, changing the LED resistors to 1K (glad Mike caught that, I meant to calculate the actual value but never got around to it) and a couple of other small changes. :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 11:02:48 pm
Speaking of supply etc., has any effort yet been put into BOM minmisation?
Do you mean the last 2 pages on timb's schematic here:
Here's the updated schematic:

http://timb.us/PDF/Scope_Pong_20170406.pdf (http://timb.us/PDF/Scope_Pong_20170406.pdf)

Edit: Fixed link to schematic.

Seems like there may be some scope for optimisation - just looking at the BOM list
33 different resistor values
100uf 16v and 25v
two different types of 10u 25V

One 10u is a bi-polar AE Cap, the other is just a standard polarized one used in several places. I could put two standard ones back to back I guess, but I never liked doing that.

The 100uF 16V is Tantalum and *has* to be Tantalum because it's used in an Integrator, so low leakage is needed. The 25V one is used in two places on the power supply: 1) For ripple reduction on the base bias resistors; 2) As bulk decoupling on the output.  Now, I *could* up the 16V Tantalum to 25V and use it all three places, but it would be a lot more expensive. The Tantalum is like $1 vs $0.33 for the AE cap, so I think it's better off having two separate types.

Edit: The 100u cap on the base bias resistors could be reduced to 10u, however output ripple will increase from about 500uV to around 5mv (at a 200mA load).

The output cap may be able to be reduced as well, as we'll have additional (optional) bulk decoupling down the line, however I specced 100uF to be safe until I test an actual finished board.

(By the way, when you look at my schematic, if you zoom in you can see a label to the top right of any non-ceramic cap that tells you what it is; AE for Aluminum Electrolytic, Tant for Tantalum, Film for Metalized Polypropylene Film, etc.)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 06, 2017, 11:38:47 pm
You know, it just occurred to me... I wonder if there would be any issues placing the LED before the 1K resistor that biases the Zener diode in the power supply circuit? Drop the resistor down to 800 Ohms or so and boom. There's plenty of headroom and it seems to work fine in basic simulation.

The idea being were already draining a constant 8mA biasing the Zener, so why not put the power supply indicator LED in-line with the biasing resistor and put that current drain to use. Two birds with one stone.

Edit: Scratch that. Under some situations this can cause a weird oscillation loop during startup, preventing it from reaching the full output voltage. I suspect the voltage drop of the LED causes this. It might be fixable by adjusting the position of the LED in the circuit, but I'll stick with what works.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 07, 2017, 10:37:21 am
Okay, I added changes to the power supply section:

(http://timb.us/images/Power_V2.png)

http://timb.us/PDF/Scope_Pong_Power_V2.pdf

The power switch and transformer connector will be moved a bit further from the regulators when placed in the final location on the board, but otherwise I incorporated all the changes described earlier.

Updated Schematic:

http://timb.us/PDF/Scope_Pong_20170407.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: calli on April 07, 2017, 11:28:29 am
Just reply to say that is quite impressive crazy!

 :clap: :clap: :clap: :clap:

I am doing some stuff with micros controlling beams but this now seems quite lame after seeing yours.

Carsten
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 08, 2017, 02:49:47 am
He he he............... just wait 'till you see the raster video version............ Am soldering lots of MPSH10 for the digital parts now (BC550C too slow here)...........

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=306581;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 08, 2017, 02:54:03 am
Will you be adjusting the ball vertical speed & direction depending on where it is hit on the paddle?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 08, 2017, 03:05:45 am
Will you be adjusting the ball vertical speed & direction depending on where it is hit on the paddle?



The current plan is to differentiate the paddle vertical control signals from the controller potentiometers and sample-and-hold the output at the moment of collision between ball and paddle; the DC potential at the output of the S&H being the balls velocity vector. This way the speed of the ball is determined by how fast the paddle is moving vertically at the moment of impact.

 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 08, 2017, 03:40:06 am
Don't forget a 50hz/60hz switch.  With this, since there is no color, the mono video would work with most TV and video capture cards around the world.  Only the capture cards with super-strict H&V timing, ie they wont support VCR playback in some cases, will fail to lock onto your video.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 08, 2017, 12:18:15 pm
Today I finished the Function Generator section and started tying together the top board:

(http://timb.us/images/Function_Generator_1.png)

(http://timb.us/images/Function_Generator_2.png)

http://timb.us/PDF/Scope_Pong_Function_Generator.pdf

Here's a low resolution render (there's so many parts it literally takes 10 minutes to load the 3D view in high quality) of how the top board is coming together. (I'm still positioning all the elements together, but it's a good start!)

(http://timb.us/images/Top_Board_170408.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 08, 2017, 04:36:55 pm
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.



Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 08, 2017, 05:12:15 pm
Timb, very nice.  1 thing you should do is add thermal relief for the GND flood fill.  For hand made boards, it's hard to soldier or repair solid copper fill + for the diodes, it helps to see pad #1, the square pad, for orientation if it is inside the fill.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 08, 2017, 05:14:29 pm
And who is Brian?
;D
I'm the evil overseer  >:D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 08, 2017, 09:43:36 pm
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.

Yeah, that's a good idea! I think I can fit it behind the power supply. The sound generation circuits might not fit, but the amplifier should no problem.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 08, 2017, 09:54:05 pm
Timb, very nice.  1 thing you should do is add thermal relief for the GND flood fill.  For hand made boards, it's hard to soldier or repair solid copper fill + for the diodes, it helps to see pad #1, the square pad, for orientation if it is inside the fill.

I assume you mean adding thermal reliefs to the top and bottom copper pours? Yeah, I can do that. I just need to go in and switch the top and bottom pours from direct to 4-sided thermals.

I was debating on if I should go direct or 4-sided; I've always preferred direct when possible, as I feel the pads have much, much less, of a chance of lifting during rework. I guess I could always turn thermals on for one set of Gerbers (for homemade boards) and off for another (for professional boards with soldermask). Hmmm...

The only thing that won't have thermals are the solder pins for the TO-220 heatsinks. You'll need a decent iron for that (or a heat gun/hairdryer/hot air pencil to pre-heat the heatsinks while you solder the pins; I've made the pads massively oversized to take the extend heat needed during soldering).

Can you elaborate on your second point about square pads being easier to see inside a fill? I'm not quite sure I understand.

Edit: Never mind, I understand. Home etched boards won't have soldemask to mask out the shape of pads directly connected to a copper pour; if you use thermals on these planes, the shape of the pads will be masked out due to the copper being pulled back around them. Gotcha. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 08, 2017, 09:58:56 pm
Square pad for diodes signifies cathode. For homemade PCB's I like to also add a small K symbol in the copper.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 08, 2017, 10:43:48 pm
Square pad for diodes signifies cathode. For homemade PCB's I like to also add a small K symbol in the copper.

Yeah, I get that and I'm already using square pads. I think I understand what BrianHG means now: A homemade PCB won't have soldermask, so if a particular pad connects to the ground plane, it'll just be a hole in the solid copper plane (that is, the shape of the pad won't be visible because there's no soldermask to, uh, mask it out). However, if you use thermal reliefs on all pads connecting to the plane, the shape of the pad *will* be visible, because the copper is backed off around the pad (except for the 2 or 4 traces that connect it to the plane).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 08, 2017, 10:50:16 pm
Very good point. I get it now too.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 08, 2017, 10:57:08 pm
Very good point. I get it now too.

Though, when you think about it, does it really make a difference? After all, it's not like both pads of a diode will be connected to a copper pour, right? So you *will* see the shape of one of the two pads; if it's round you know the other is square and vice versa.

That said, the thermals *do* make it easier to solder.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 08, 2017, 11:09:04 pm
For identification, it may be helpful to those newer to electronics. More a belt and suspenders thing, I suppose, to minimize assembly errors.

Definitely a good thing for soldering. That board has quite a ground plane. Working on vintage power supplies, I do keep my big ol' Weller soldering gun nearby for just such an occasion. :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 09, 2017, 10:28:32 am
For identification, it may be helpful to those newer to electronics. More a belt and suspenders thing, I suppose, to minimize assembly errors.

Definitely a good thing for soldering. That board has quite a ground plane. Working on vintage power supplies, I do keep my big ol' Weller soldering gun nearby for just such an occasion. :-+

Yeah, and the ground plane may be getting bigger! Initially I had planned on two 250x250mm boards stacked, however tonight I've discovered I may be able to fit everything on a single 250x350mm board. The price isn't that much higher for the extra board size ($14 for a single board) but we save by only needing one board.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 09, 2017, 10:31:59 am
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.

I worked on the Sound section tonight. The amplifier is pretty small and easily fits next to the power supply.

(http://timb.us/images/Audio_Amp.png)

I've also added a footprint for a PCB mount right angle pot instead of a connector for an external pot. If the user wants to go that route they could install a terminal block in place of the PCB mount pot, since they're both 5mm pitch.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 10, 2017, 03:32:09 am
Initially I had planned on two 250x250mm boards stacked, however tonight I've discovered I may be able to fit everything on a single 250x350mm board. The price isn't that much higher for the extra board size ($14 for a single board) but we save by only needing one board.

Sounds good to me.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 10, 2017, 04:32:43 am
Initially I had planned on two 250x250mm boards stacked, however tonight I've discovered I may be able to fit everything on a single 250x350mm board. The price isn't that much higher for the extra board size ($14 for a single board) but we save by only needing one board.

Sounds good to me.

+1
Yes, one board sounds much better.

It also means that if it is done as a display piece, ALL the electronics can easily be seen. It probably makes casing it less essential, and arguably easier to case if you do.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 10, 2017, 11:27:47 am
Good points, plus then the "Equivalent Circuit" silkscreens will be easily visible for the entire thing, which makes it nice from a display point of view.

(http://timb.us/images/PCB_Diagram.png)

Yes, I sat down one night and made a pattern library full of schematic symbols for PCB silkscreens (I could also convert them to the copper layer). They're handy for various things, such as visually labeling components and placing diagrams on boards.

(http://timb.us/images/PCB_Symbols.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 10, 2017, 06:12:18 pm
Wow, those silkscreen symbols and schematics look great, Tim! Now this'll have to go in a transparent acrylic case.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 11, 2017, 01:09:11 pm
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.

I worked on the Sound section tonight. The amplifier is pretty small and easily fits next to the power supply.




Looks neat but that's a tiny loudspeaker! Have you used one of those before? I hope the amplifier isn't too powerful for it and deflects the cone to Xmax at 1/4 volume.

BTW, if you're not ponged out already and think you might be hankering for another PCB layout project after this is done, I'm currently well into soldering something together which is taking this discrete transistor Pong thing to another level  ;)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 11, 2017, 01:36:10 pm
Don't forget a 50hz/60hz switch.  With this, since there is no color, the mono video would work with most TV and video capture cards around the world.  Only the capture cards with super-strict H&V timing, ie they wont support VCR playback in some cases, will fail to lock onto your video.


Actually I intend to implement a fully colour-encoded composite video signal. It's going to be PAL only (15625Hz H, non interlaced, 312 lines V, 50.08Hz). Attempting to accommodate both the PAL standards and the different frame/field rate and vertical resolution of NTSC as well as the alternate colour encoding isn't something I could be bothered with; and more so since I don't have an NTSC TV or monitor to test it with! If this turns out to be a project that anyone in a non-PAL land feels like replicating the option there is to play discrete transistor pong on your modern flat screen TV courtesy of a composite video to HDMI converter, I guess.

The last time I assembled colour composite video from discrete RGB it was with an AD723, but my design reference now for this endeavor is the composite video generator circuit inside my BBC Model B microcomputer, which I've always admired as a feat/demonstration/example of minimalist engineering. They did it with TTL logic and minimal analogue. There is a very thorough technical write up of the circuitry in one of my technical/service manuals and I don't see any real/obvious  hassle with replicating the function with discrete transistors.
     
I currently have all of the horizontal timing and video signal circuits complete and am ~1/2 way through the vertical. Once I've finished the latter in another couple of nights I'll be able to display a basic B&W video raster with blank scoreboard and court net immediately. The step after that will be to get the digits displaying on the scoreboard after soldering up the a gate array which assembles/combines the discrete H and V video signals for the digit segments.

My score counters shown as single digit in my prior post have since been increased by 1/2 a digit to count from zero to 19. I realised that all this added to my score counters in the way of further complication was an additional carry/overflow flip-flop to activate the 1/2 segment, which is trivial enough to accommodate. So my (currently completed) horizontal video generator board (300mm x 150mm) now also produces a discrete video signal high during horizontal timing interval #6 and another high at #18 for the 1/2 segments. The player to reach 19 wins first will be the winner.

Also I've divvied the paddles into sections and the ball will deflect at 45 degrees if it hits the middle section and 67.5 degrees if it hits the outer sections. The bat sizes will also be variable. I'm looking forward to reaching the stage where I can start it take some raster display photos.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 11, 2017, 02:14:42 pm
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.

I worked on the Sound section tonight. The amplifier is pretty small and easily fits next to the power supply.




Looks neat but that's a tiny loudspeaker! Have you used one of those before? I hope the amplifier isn't too powerful for it and deflects the cone to Xmax at 1/4 volume.

BTW, if you're not ponged out already and think you might be hankering for another PCB layout project after this is done, I'm currently well into soldering something together which is taking this discrete transistor Pong thing to another level  ;)
Should at least have an option for terminals for external speaker, maybe 3.5mm jack ( linkable for speaker or line level ?)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 11, 2017, 05:02:44 pm
Actually I intend to implement a fully colour-encoded composite video signal. It's going to be PAL only (15625Hz H, non interlaced, 312 lines V, 50.08Hz).

...snip...

My score counters shown as single digit in my prior post have since been increased by 1/2 a digit to count from zero to 19. I realised that all this added to my score counters in the way of further complication was an additional carry/overflow flip-flop to activate the 1/2 segment, which is trivial enough to accommodate. So my (currently completed) horizontal video generator board (300mm x 150mm) now also produces a discrete video signal high during horizontal timing interval #6 and another high at #18 for the 1/2 segments. The player to reach 19 wins first will be the winner.

Also I've divvied the paddles into sections and the ball will deflect at 45 degrees if it hits the middle section and 67.5 degrees if it hits the outer sections. The bat sizes will also be variable. I'm looking forward to reaching the stage where I can start it take some raster display photos.

Wow! Major upgrade already. Things move fast on the bleeding edge of Pong, The Revival. :popcorn:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 11, 2017, 05:28:18 pm
Looks good. I wonder if you could fit the audio power amplifier in there. A good place for it would be directly in front of the power supply, on its own partitioned ground plane section, star-earthed at the PSU common. That way you won't have the heavy speaker currents (up to several hundred mA) pumping through your board interconnects and ground plane.

I worked on the Sound section tonight. The amplifier is pretty small and easily fits next to the power supply.




Looks neat but that's a tiny loudspeaker! Have you used one of those before? I hope the amplifier isn't too powerful for it and deflects the cone to Xmax at 1/4 volume.

BTW, if you're not ponged out already and think you might be hankering for another PCB layout project after this is done, I'm currently well into soldering something together which is taking this discrete transistor Pong thing to another level  ;)

Last night  I was actually thinking about the speaker. I've used one before, but it's only 200mW, which might be OK (if not a bit weak), however the frequency response is *very* poor below 500Hz, which is where some of our sounds are!

So, I decided to remove the speaker from the PCB itself and simply add a 5mm terminal block. That way the user can implement a 2W 60mm chassis mount speaker, or a 3.5mm audio jack on the chassis, whatever they want. Something like this might be ideal for an external speaker: 14x21mm 1.5W Speaker (https://www.digikey.com/product-detail/en/cui-inc/CDS-25148-L100/102-3545-ND/5355540)

That one is still small enough that it could be mounted to the PCB itself (I could provide mounting holes on the PCB, and the user could use standoffs to mount it.)

And yes, I saw that little preview of your next project and I'd love to do a PCB of that one as well! How many components are we looking at on that one? :D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 11, 2017, 05:53:15 pm
Uh oh. Glen, did your site get too much traffic? Seems to have been suspended.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 11, 2017, 09:33:05 pm
Uh oh. Glen, did your site get too much traffic? Seems to have been suspended.

Yeah, I see it too.

GK, if you need more bandwidth I can give you space on my server. I've got a several TB bandwidth cap on a dedicated virtual server, so there's plenty to go around.

If you want, you could just point a subdomain at my sever and store assets (PDFs and images) on it or you can host everything there. Just let me know and I'll set you up with some FTP credentials or whatever you need. :)

(I host for a couple of other forum members as well, so this offer applies to anyone who wants some space to setup a website for their projects.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 11, 2017, 10:33:40 pm
Actually I intend to implement a fully colour-encoded composite video signal. It's going to be PAL only (15625Hz H, non interlaced, 312 lines V, 50.08Hz). Attempting to accommodate both the PAL standards and the different frame/field rate and vertical resolution of NTSC as well as the alternate colour encoding isn't something I could be bothered with; and more so since I don't have an NTSC TV or monitor to test it with! If this turns out to be a project that anyone in a non-PAL land feels like replicating the option there is to play discrete transistor pong on your modern flat screen TV courtesy of a composite video to HDMI converter, I guess.

All color for a pong game, in transistors.  Wow.  I mean WOW!  If you were to do monochrome, all you had to do was change your vertical counter to 265 to support all the 60hz formats.  The horizontal is close enough and the text would be a little stretched, or, you could say the text would be a little squished when operating in any 50hz system, PAL or Secam...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 11, 2017, 10:37:27 pm
Actually I intend to implement a fully colour-encoded composite video signal. It's going to be PAL only (15625Hz H, non interlaced, 312 lines V, 50.08Hz). Attempting to accommodate both the PAL standards and the different frame/field rate and vertical resolution of NTSC as well as the alternate colour encoding isn't something I could be bothered with; and more so since I don't have an NTSC TV or monitor to test it with! If this turns out to be a project that anyone in a non-PAL land feels like replicating the option there is to play discrete transistor pong on your modern flat screen TV courtesy of a composite video to HDMI converter, I guess.
I wonder if RGB VGA might be a more versatile choice.

All color for a pong game, in transistors.  Wow.  I mean WOW!  If you were to do monochrome, all you had to do was change your vertical counter to 265 to support all the 60hz formats.  The horizontal is close enough and the text would be a little stretched, or, you could say the text would be a little squished when operating in any 50hz system, PAL or Secam...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 11, 2017, 11:09:51 pm
''' I mean WOW!!!! '''   If I were to attempt it, I would cheaply do a VGA RGB 640x480 60hz, separate H&V 5v sync signals for compatibility with any PC Monitor today with world wide compatibility... Even digital flat panel monitors...  The simplicity of the video outputs being 0v for black & anything else for color.  No mixed in sync or stabilization pulses, or front & back porch signals.

But a PAL carrier burst, H&V front and back porch signals, vertical time stabilization pulses.  Hell, you might even lace the VS for fun and bragging.  I could not imagine going that today with just transistors, diodes, and j-fets.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 11, 2017, 11:18:46 pm
I know, right? Amazing stuff.

What's next, GK? Tempest (https://en.wikipedia.org/wiki/Tempest_(video_game))? :o 8)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 11, 2017, 11:28:45 pm
Tempest in transistors only :scared:

Ok, maybe we got to stay in the world of reality.  Perhaps a simplified version of asteroids, where you either stay in the center and shoot in multiple directions moving/approaching dented/spheres/ovals/maybe rotating of a few sizes.  Say 8 play-field objects.

-or-

Have a play-field of multiple spheres bouncing around, alternating trajectories off the 4 sides of the scope, and you, need to maneuver out of the way with an x/y paddle running against a clock.  The highest time wins...

-or-

16 play-field objects, 1 player, 3 bullets, 12 asteroids, 4 of 3 sizes each.  Skip those silly alien saucers.

I could imagine GK creating one of these 2 games transistor only using the existing functions in the pong game.


GK, pull off one of the first 2, and you blow everyone away.  Pull off the third one and you will be the GOD of the transistor only video game, no one on earth will touch you.  (Variations on the how to multiplex the ball oscillator, mixing in a bit of the triangle and square wave to make a ragged edge, or, shooting the asteroids would instead of destroy them, just push the away from your shot.  You don't need to make a perfect asteroid game simulation, just a game you can play with maybe even 2 players which is much more interesting and complex and fun compared to simple pong...)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 12:03:17 am
There was a fiasco 6 months or so back with my hosting service loosing a server and nobody being able to get a response from technical support for weeks on end (my tickets took four weeks or more).

At the time I requested that my account be suspended at the end of the billing period which is due the coming Monday. The host seems to have pulled itself together in the meanwhile and since I'm lazy and haven't bothered shifting to a new host yet and as crunch time is a few days away I emailed the host last night asking if the scheduled cancellation could be reversed. They replied by immediately suspending my account "as requested", FFS.  :palm:

I've notified them of their misinterpretation and am waiting for a response!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 03:00:13 am
Just had a quick lunch break peekaboo and my site is back on-line. Was just a misinterpretation, not an issue to devote any further thought to! Now I'm hungry............
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 12, 2017, 03:06:24 am
Thanks for the update, GK. Bon appetit!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 12, 2017, 03:18:27 am
Just had a quick lunch break peekaboo and my site is back on-line. Was just a misinterpretation, not an issue to devote any further thought to! Now I'm hungry............
Didn't you have the pong game .pdf on your web site?
Your new stuff is gone.  Your current web site is an old backup....
Even your .pdf pong document in this thread's opening topic still says 'You account is still 'Suspended''...  Try downloading it...
You probably need to re-upload everything changed over the past year...
I'd verify the contents of everything else just in case.

So says the evil overseer.  >:D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 08:58:02 am
Just had a quick lunch break peekaboo and my site is back on-line. Was just a misinterpretation, not an issue to devote any further thought to! Now I'm hungry............
Didn't you have the pong game .pdf on your web site?
Your new stuff is gone.  Your current web site is an old backup....
Even your .pdf pong document in this thread's opening topic still says 'You account is still 'Suspended''...  Try downloading it...
You probably need to re-upload everything changed over the past year...
I'd verify the contents of everything else just in case.

So says the evil overseer.  >:D


It's all working for me bloke.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 12, 2017, 09:03:12 am
Just tried it again.  It now works.  Probably something still in cache...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 01:38:01 pm
''' I mean WOW!!!! '''   If I were to attempt it, I would cheaply do a VGA RGB 640x480 60hz, separate H&V 5v sync signals for compatibility with any PC Monitor today with world wide compatibility...


I really want to play it on my living room flat screen though and the old CRT TV in the workshop.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 01:47:37 pm
I currently have all of the horizontal timing and video signal circuits complete and am ~1/2 way through the vertical. Once I've finished the latter in another couple of nights I'll be able to display a basic B&W video raster with blank scoreboard and court net immediately. The step after that will be to get the digits displaying on the scoreboard after soldering up the a gate array which assembles/combines the discrete H and V video signals for the digit segments.


Didn't think that I would get this far already this evening! Yoo Hoo! Raster! Next up is the gate array now necessary to assemble the discrete video components of the scoreboard digit segments.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=307637;image)

A little circuit tease:  ;D

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=307639;image)

The scoreboard digit arrangement, comprised of 7 overlapping segments plus and 8th segment for the 1/2 digit:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=307641;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BravoV on April 12, 2017, 01:54:30 pm
Just for the look, without the flood fill, isn't that look more '70 ? Just some wild idea.

Not sure how it perform or affect the circuit performance.  :-//
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 12, 2017, 06:09:01 pm
Didn't think that I would get this far already this evening! Yoo Hoo! Raster!

When you start surprising yourself, GK, we have no hope to catch up. :-DD Despite the speed, your wiring still looks beautiful.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 12, 2017, 06:17:26 pm
Didn't think that I would get this far already this evening! Yoo Hoo! Raster!

When you start surprising yourself, GK, we have no hope to catch up. :-DD Despite the speed, your wiring still looks beautiful.

OMG, already?   :scared: :scared: :scared:
I'm freaking out...  :clap:
Does your big screen lock on to your raster?
You must be having too much fun with this...
Enjoy the thrill...

(I'm getting worried that after this, we will see an all transistor multi-ball asteroids type game I mentioned earlier...)

(I also worked with Commodore's 1080s & 1084s monitors...)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 12, 2017, 09:54:24 pm
Just for the look, without the flood fill, isn't that look more '70 ? Just some wild idea.

Not sure how it perform or affect the circuit performance.  :-//

Right now we're talking about a 250x400mm board; I'm already having enough trouble simply routing the +/-15V rails across it, but if I had to route the GND connections by hand it would be a nightmare.

I would also have to go back and re-layout the 3/4 of the board I've already done, as the current layout is done with a ground plane in mind.

Anachronism aside, the copper pours will have to remain. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 12, 2017, 09:59:49 pm
''' I mean WOW!!!! '''   If I were to attempt it, I would cheaply do a VGA RGB 640x480 60hz, separate H&V 5v sync signals for compatibility with any PC Monitor today with world wide compatibility...


I really want to play it on my living room flat screen though and the old CRT TV in the workshop.

So you're doing this for 50Hz PAL, right? How hard would it be to change to 60Hz NTSC? (I haven't seen the schematics yet, so I don't know how much of the rest of the circuit depends on the PAL timing, or if you've made it modular.)

I don't think I've got any monitors that can do PAL. :(

If it were me, I'd go VGA as it's pretty universal these days, most TVs have inputs for it and old monitors are cheap and plentiful.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 12, 2017, 10:49:48 pm

Right now we're talking about a 250x400mm board; I'm already having enough trouble simply routing the +/-15V rails across it, but if I had to route the GND connections by hand it would be a nightmare.

Power round the outside edge perhaps, on same layer as groundplane?
Make it a ring to reduce drop.

Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 12, 2017, 11:30:54 pm

Right now we're talking about a 250x400mm board; I'm already having enough trouble simply routing the +/-15V rails across it, but if I had to route the GND connections by hand it would be a nightmare.

Power round the outside edge perhaps, on same layer as groundplane?
Make it a ring to reduce drop.

Yeah, that's exactly what I'm trying to do right now. +15V on the top, -15V on the bottom run on top of each other around the entire periphery of the board. Using 80mil traces for the ring. The various circuit blocks will tap off from it with 50mil traces.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 12, 2017, 11:34:48 pm
I don't think I've got any monitors that can do PAL. :(



Really not a problem. If your modern flat screen TV has a composite video input there is a 99% chance it will support both NTSC and PAL and most likely SECAM too. If not you just need one of these:

https://www.jaycar.com.au/composite-av-to-hdmi-converter/p/AC1722 (https://www.jaycar.com.au/composite-av-to-hdmi-converter/p/AC1722)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 12, 2017, 11:36:55 pm
I don't think I've got any monitors that can do PAL. :(



Really not a problem. If your modern flat screen TV has a composite video input there is a 99% chance it will support both NTSC and PAL and most likely SECAM too. If not you just need one of these:

https://www.jaycar.com.au/composite-av-to-hdmi-converter/p/AC1722 (https://www.jaycar.com.au/composite-av-to-hdmi-converter/p/AC1722)

Hmm, I didn't know that. My TV is an older Panasonic Plasma, circa 2009. I'll look it up and see if it supports PAL!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 13, 2017, 02:26:19 am
Hmm, I didn't know that. My TV is an older Panasonic Plasma, circa 2009. I'll look it up and see if it supports PAL!

If you have access to an old Amiga 500, or 2000, I'll get you the jumper # on the motherboard and you will be able to switch the composite video out from NTSC to PAL, though, it will be monochrome and off by a fraction of a few fraction of 1 Hz, though your TV should lock to this anyways.  Otherwise, it wouldn't support VHS playback who's scan rate sways due to the speed of the video head speed being imperfect.

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on April 13, 2017, 07:11:16 am
Most NTSC and PAL monitors will sync to each others systems at least to some degree, although you will typically have excessive underscan, overscan or the picture may not center. NTSC and PAL actually refer only to the method of encoding color over the legacy B&W image, so a monochrome composite video signal without a colorburst is technically neither NTSC or PAL.

Nowadays it's all kind of boring, TVs are all digital and it's easier to make them all able to work with all video formats that design different boards for different markets. I've seen US-market TVs that had inside a spot on the PCB for a SCART connector and the associated components.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 13, 2017, 10:35:18 am
Hmm, I didn't know that. My TV is an older Panasonic Plasma, circa 2009. I'll look it up and see if it supports PAL!

If you have access to an old Amiga 500, or 2000, I'll get you the jumper # on the motherboard and you will be able to switch the composite video out from NTSC to PAL, though, it will be monochrome and off by a fraction of a few fraction of 1 Hz, though your TV should lock to this anyways.  Otherwise, it wouldn't support VHS playback who's scan rate sways due to the speed of the video head speed being imperfect.


No Amiga, but I do have a nice Tektronix AWG that I can load waveforms into over USB. Maybe I can find the CSV of a captured PAL signal somewhere, load it up and hook it into my TV to see if it locks.

I looked through the manual last night but didn't see anything referencing PAL.

Even if it doesn't support it I can always get a Universal Composite to HDMI adapter. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 13, 2017, 10:38:07 am

Right now we're talking about a 250x400mm board; I'm already having enough trouble simply routing the +/-15V rails across it, but if I had to route the GND connections by hand it would be a nightmare.

Power round the outside edge perhaps, on same layer as groundplane?
Make it a ring to reduce drop.

So this is what I ended up doing. I think it'll work out perfectly:

(http://timb.us/Projects/Scope_Pong/PCB_Top_20170413.png)

(http://timb.us/Projects/Scope_Pong/PCB_Bottom_20170413.png)

http://timb.us/Projects/Scope_Pong/Layout_20170413.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 13, 2017, 12:05:43 pm
Surprised you've done that much routing before finishing placement to see how much things can be pushed together to reduce overall size (I'm assuming there's quite a bit more to fit onto that layout). Seems to be quite a lot of unused space near the BNCs that the bottom-left corner stuff could be pushed into.
As mentioned earlier,people may want to display it, so there should be room to lay the regulators and tall caps flat to allow a sensible distance to a clear cover.
You certainly also want a few more mounting hole locations for a PCB that size, and some near the BNCs for support in case the panel-mount isn't used.


Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 13, 2017, 01:03:45 pm
Surprised you've done that much routing before finishing placement to see how much things can be pushed together to reduce overall size (I'm assuming there's quite a bit more to fit onto that layout). Seems to be quite a lot of unused space near the BNCs that the bottom-left corner stuff could be pushed into.
As mentioned earlier,people may want to display it, so there should be room to lay the regulators and tall caps flat to allow a sensible distance to a clear cover.
You certainly also want a few more mounting hole locations for a PCB that size, and some near the BNCs for support in case the panel-mount isn't used.

Yeah, there's quite a bit more to be done that I haven't laid out yet. Also, keep in mind some of routing between sections is just a test and not necessarily final. That PDF/image is just meant to show off the power bus more than anything. That said, I can only push things together *so* much because in certain areas I have to leave significant room to route traces between sections, for via stitching and additional mounting holes. I'm also leaving some small sections of free space to draw equivalent circuit diagrams and label the various sections on the silkscreen layer. (If that means the board has to be 400mm vs 350mm so be it; I think the end result will be worth it.)

Speaking of mounting holes, yes, I plan on adding several more mounting holes towards the middle and inner sections of the board. I'm just waiting to until I get more of the layout finished before placing them.

By the way, I *do* appreciate the feedback from everyone. I've designed 8 layer boards with 300-pin BGA packages that somehow seem *less* complex than this; having only two layers and quite a few interconnects between sections makes routing this a challenge; I'm sure there are areas where I could have laid things out more efficiently. So keep the feedback coming, it helps! :)

Edit: I did want to go back and push that Z-Axis block in the bottom left more towards the BNC. Now that I've got the power bus figured out I can do that. I can maybe get an additional 10-20mm out of it I think. That would also put the Multiplexer Logic/Gate Driver's more in line with the input diodes that feed the actual JFET switches, so I'd save area by shortening those traces too.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on April 13, 2017, 01:13:06 pm
By the way, I *do* appreciate the feedback from everyone. I've designed 8 layer boards with 300-pin BGA packages that somehow seem *less* complex than this; having only two layers and quite a few interconnects between sections makes routing this a challenge; I'm sure there are areas where I could have laid things out more efficiently. So keep the feedback coming, it helps! :)

Just leave enough room between all components and hit the auto router button, no problem with all these big through hole parts :D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 13, 2017, 09:36:02 pm
Just leave enough room between all components and hit the auto router button, no problem with all these big through hole parts :D
Auto-router ->>>>>  :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared:

Ok, I realize your just being cheesy...

Timb is doing perfectly.  Wait till everything is done, then maybe a go-over removing jumpers if possible...
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 13, 2017, 11:32:24 pm
Just leave enough room between all components and hit the auto router button, no problem with all these big through hole parts :D

I actually tried that at one point, just to see how it would try to route the entire giant board in one go. I set it up, started it and wandered off to do some chores. It was only 1/4 done an hour later, so I gave up.

I might start a blank board, renew it from schematic and let it run overnight just to see what sort of spaghetti nonsense it comes up with! :D (When I finish the manual board I can use it to show the difference between a human and autorouter.)

Auto-router ->>>>>  :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared: :scared:

Ok, I realize your just being cheesy...

Timb is doing perfectly.  Wait till everything is done, then maybe a go-over removing jumpers if possible...

Do you mean wire jumpers or vias? There's currently zero wire jumpers (and none planned). There are some vias, but they can't be helped. I'm trying to keep them to a minimum for you guys etching at home since I know you have to solder a piece of wire through the hole which is kind of a pain.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 14, 2017, 12:03:45 am
What jumpers? There's currently zero wire jumpers (and none planned). There are some vias, but they can't be helped. I'm trying to keep them to a minimum for you guys etching at home since I know you have to solder a piece of wire through the hole which is kind of a pain.
Ok, it's what I meant, but it's not the end of the world...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 14, 2017, 12:21:08 am
What jumpers? There's currently zero wire jumpers (and none planned). There are some vias, but they can't be helped. I'm trying to keep them to a minimum for you guys etching at home since I know you have to solder a piece of wire through the hole which is kind of a pain.
Ok, it's what I meant, but it's not the end of the world...

Ah, gotcha. Yeah, I'm really trying to minimize them, but it's difficult with only two layers and all the nets running between sections.

There will also be some via stitching of the top and bottom ground planes to keep ground continuity, however, for the majority of the board they won't be an absolute necessity (as various pins are grounded and will act to bridge the two sides). So if you're etching the board at home, only a couple of the stitching vias will have to be drilled and soldered; I'll make sure the ones that are mandatory have thermals, so they can be easily identified.

Also, I'm using 0.75/1.5mm as the smallest via size, to make it easy to drill. (That's also the hole/ring size of 90% of the parts.)

Hopefully this is an acceptable compromise. :)
Title: Video Pong.......
Post by: GK on April 14, 2017, 09:33:39 am
I put the soldering iron away this afternoon and made a start at documenting this discrete-transistor Pong MkII. This is mostly because the circuits were part scribbled on multiple sheets of paper and part in my head. By alternating between soldering and documenting the design I have less chance of getting lost.

Here are complete details of the horizontal timing and video generator board. A master LC oscillator of 500 kHz clocks a 5-bit binary ripple counter made up of cascaded toggle flip-flops.
The necessary video signals are simply decoded by (N)AND gates. Some trickery was required here however as this method of decoding a ripple counter is prone to glitches in the decoded outputs as the clock state ripples through the binary counter due to the propagation delays of the flip-flops. Glitches on the decoded outputs are not acceptable here as the video signals are being generated live as each horizontal line is being scribed on the display screen.

I solved this problem by designing the flip-flops of the ripple counter to be quite fast (using MPSH10 transistors) and conversely designing and (N)AND gates for decoding to be only adequately fast for the application, rather than excessively so, such that the decoders are too slow, by a comfortable margin, to respond to and pass through the erroneous binary states of the counter during the ripple-through of the clock.

The DTL (diode-transistor-logic) N(AND) gates are made "slow" by using comparatively-lowly BC550C transistors with a relatively weak base pull-up. The AND gates that provide the horizontal video signals for generating the scoreboard display digit segments are comprised of a BC550C NAND followed by an MPSH10 DTL inverter. The through-put propagation delay of this combo is a clean and stable ~120nS and the MPSH10 inverter provides (in addition to the required polarity inversion) a squared-up output with fast rise and fall times.

The MSB (HR16) of the horizontal ripple counter is at the line frequency (15,625 kHz) and it is used as the clock source for the vertical line counter. The horizontal video component of the paddles and the court net are approximately 600nS wide and 300nS wide respectively. As this is substantially less than the 2uS master clock period, these video signals are produced by triggering high-speed monostables.

All of the signal outputs of the horizontal timing unit are digital, bar "H_SCAN", an analogue line-scan ramp signal. H_SCAN is provided for the Ball Horizontal Movement circuit.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308145;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308147;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308149;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308151;image)

The board itself. I currently have a rather crappy ferrite-cored "choke" with a rather poo temperature coefficient soldered into the tank circuit of the master oscillator, as this is what immediately at hand. I'll will be sourcing a better core material to wind a better substitute. 

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308153;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 14, 2017, 10:26:06 am
Using a discrete crystal or resonator in place of the coil for your master oscillator still keeps your circuit a valid all discrete design.
It will also prevent users from accidentally destroying their TV h-sync yoke driving transistor on their TVs if the inductor driven oscillator doesn't drift the H-sync by 1/4 of a KHz.  Modern digital sampling screen's ADC use tightly locked crystal PLLs, they wont be as forgiving with out of spec HSync speed compared to an all analog CRT like the Commodore 1084s monitor you are using.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 14, 2017, 10:58:01 am
Using a discrete crystal or resonator in place of the coil for your master oscillator still keeps your circuit a valid all discrete design.
It will also prevent users from accidentally destroying their TV h-sync yoke driving transistor on their TVs if the inductor driven oscillator doesn't drift the H-sync by 1/4 of a KHz.  Modern digital sampling screen's ADC use tightly locked crystal PLLs, they wont be as forgiving with out of spec HSync speed compared to an all analog CRT like the Commodore 1084s monitor you are using.


The master oscillator with the current crappy inductor is already stable enough for any analogue TV or monitor and will be amply so with a better inductor. I can't immediately see how any TV could burn out its yoke due to sync frequency drift. In the absence of a video signal the raster scan oscillators are without any signal to lock onto at all and are are free to rail out or drift around within their operating frequency limits. Back in the day hobby circuits published in electronic mags for producing video displays often used a pair or 555 timers injection-locked to each other to provide the H and V sync! I have two such "vintage" articles sitting on my desk right now and I can't recall ever reading a warning to monitor your TV for smoke in addition to a stable image whilst tweaking those 555 frequency-setting trimpots!

Resonators typically have crappy tolerances and limited scope for frequency tuning and I'm not sure if they're readily available in 500 kHz. I'm going to buy one of those composite video to HDMI converters to asses how sensitive it is to the field and frame frequency stability/accuracy. Until it is proven that the basic LC oscillator is inadequate it stays. If it does prove to be inadequate or marginal I will substitute the LC oscillator with a 2MHz crystal oscillator followed by an additional pair of toggle-flip-flops to divide down to 500 kHz - 2 MHz is the nearest readily available crystal frequency, making that the only real highter-stability master oscillator option.           
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 14, 2017, 11:18:04 am
Yes, 2Mhz crystal is the closest cheap standard crystal.
500Khz resonators are also a standard, I believe they are used for 3.5inch floppy drive motor driver oscillator clock (the orange rectangle visible and accessable on the bottom of the drive next to the motor wheel), but, the tolerance is 2khz though tunable with your varicap.
Just for reference if you are doing an existing order and looking to test, cheap stock here:
https://www.digikey.com/products/en/crystals-oscillators-resonators/resonators/174?k=resonator&k=&pkeyword=resonator&pv1989=0&pv69=80&FV=fff4000d%2Cfff80397%2Cffe000ae%2C22c00f2&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500 (https://www.digikey.com/products/en/crystals-oscillators-resonators/resonators/174?k=resonator&k=&pkeyword=resonator&pv1989=0&pv69=80&FV=fff4000d%2Cfff80397%2Cffe000ae%2C22c00f2&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500)
and here:
http://www.mouser.com/ProductDetail/ECS/ZTB500E/?qs=oGPfoFmS6kS1ad5kgPbJGw%3d%3d&utm_source=findchips&utm_medium=aggregator&utm_campaign=ZTB500E&utm_term=ZTB500E&utm_content=ECS (http://www.mouser.com/ProductDetail/ECS/ZTB500E/?qs=oGPfoFmS6kS1ad5kgPbJGw%3d%3d&utm_source=findchips&utm_medium=aggregator&utm_campaign=ZTB500E&utm_term=ZTB500E&utm_content=ECS)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 14, 2017, 11:33:56 am
Surprised you've done that much routing before finishing placement to see how much things can be pushed together to reduce overall size (I'm assuming there's quite a bit more to fit onto that layout). Seems to be quite a lot of unused space near the BNCs that the bottom-left corner stuff could be pushed into.
As mentioned earlier,people may want to display it, so there should be room to lay the regulators and tall caps flat to allow a sensible distance to a clear cover.
You certainly also want a few more mounting hole locations for a PCB that size, and some near the BNCs for support in case the panel-mount isn't used.

So I went ahead and pushed the Z-Axis amplifier and part of the multiplexer logic in about 20mm towards the left. I had to get a little craeative with routing, but it works. I also finished the sound section (ignore the placement of the three monostable timers, I plan on moving and rotating them some once I get other sections in, what's shown is where I just where I just happened to stick them before calling it a night).

I also added additional mounting holes and added equivalent circuit silkscreen to the Multiplexer Logic section (as to test to see if I could break it up and still make it understandable).

Now that I've got the existing elements tidied up and I'm happy with how things are coming, it's back to full bore on getting the final three sections completed. :)

(http://timb.us/Projects/Scope_Pong/PCB_Top_20170414.png)

http://timb.us/Projects/Scope_Pong/Layout_20170414.pdf
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 14, 2017, 06:13:30 pm
Using a discrete crystal or resonator in place of the coil for your master oscillator still keeps your circuit a valid all discrete design.
It will also prevent users from accidentally destroying their TV h-sync yoke driving transistor on their TVs if the inductor driven oscillator doesn't drift the H-sync by 1/4 of a KHz.  Modern digital sampling screen's ADC use tightly locked crystal PLLs, they wont be as forgiving with out of spec HSync speed compared to an all analog CRT like the Commodore 1084s monitor you are using.


The master oscillator with the current crappy inductor is already stable enough for any analogue TV or monitor and will be amply so with a better inductor. I can't immediately see how any TV could burn out its yoke due to sync frequency drift. In the absence of a video signal the raster scan oscillators are without any signal to lock onto at all and are are free to rail out or drift around within their operating frequency limits. Back in the day hobby circuits published in electronic mags for producing video displays often used a pair or 555 timers injection-locked to each other to provide the H and V sync! I have two such "vintage" articles sitting on my desk right now and I can't recall ever reading a warning to monitor your TV for smoke in addition to a stable image whilst tweaking those 555 frequency-setting trimpots!

Resonators typically have crappy tolerances and limited scope for frequency tuning and I'm not sure if they're readily available in 500 kHz. I'm going to buy one of those composite video to HDMI converters to asses how sensitive it is to the field and frame frequency stability/accuracy. Until it is proven that the basic LC oscillator is inadequate it stays. If it does prove to be inadequate or marginal I will substitute the LC oscillator with a 2MHz crystal oscillator followed by an additional pair of toggle-flip-flops to divide down to 500 kHz - 2 MHz is the nearest readily available crystal frequency, making that the only real highter-stability master oscillator option.           
The only time accuracy may be an issue is if you're doing colour, for the subcarrier, but that would probably be a seperate xtal anyway. The tolerance on a 500K resonator should be more than enough, and should be a lot more stable than an LC osc. 
 

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on April 14, 2017, 06:35:23 pm
There were some computer monitors that would blow the horizontal output transistor or other parts if they were fed an incompatible sync signal, but most would tolerate it at least for a while. I suppose there may be a few TV sets out there that would lock onto a wildly out of spec horizontal sync and blow up but it's not something I've ever had happen. Certainly a few percent off is not going to hurt, I've even fed PAL-50 to standard NTSC CRT TVs before and most will display it to a usable degree without dying.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 14, 2017, 09:38:36 pm
The H-sync difference between PAL and NTSC is 15.625 vs 15.734k, only a difference of 0.109khz.  CRTs wont even feel the difference.  Even your analog VRC's playback jitters it's H time timing within this range.  Though, the H yoke drive in CRT is fairly strong with a tight PLL lock since after drawing a slow line, it needs to fly back from right to left really fast and going too far out may have consequences.

As for the vertical, 50hz to 60hz, the vertical's return speed after drawing a frame is a much slower action and this guy, you may easily stretch from 45hz to 65 or even 70hz without frying anything, or, the slow VS PLL in the monitor just wont lock and you will see that scrolling bar.

With the worst possible +/- 2khz error on the 500khz resonator I listed, GK's H sync generator would be from 15.562-15.625-15.6875Khz.  The error doesn't even make it to NTSC's 15.734k.  For B&W, the listed resonator is a safe cheap 0.7$ reference which wont destroy any monitors at all and would probably drop into his current circuit with ease.  He could even cheapen it up with a 2 transistor oscillator instead of the current 6 if he likes.  Just accidentally touching a point with your finger on the inductor tuned oscillator will go way further out of bounds.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 15, 2017, 12:24:17 am
I put the soldering iron away this afternoon and made a start at documenting this discrete-transistor Pong MkII. This is mostly because the circuits were part scribbled on multiple sheets of paper and part in my head. By alternating between soldering and documenting the design I have less chance of getting lost.

Here are complete details of the horizontal timing and video generator board. A master LC oscillator of 500 kHz clocks a 5-bit binary ripple counter made up of cascaded toggle flip-flops.
The necessary video signals are simply decoded by (N)AND gates. Some trickery was required here however as this method of decoding a ripple counter is prone to glitches in the decoded outputs as the clock state ripples through the binary counter due to the propagation delays of the flip-flops. Glitches on the decoded outputs are not acceptable here as the video signals are being generated live as each horizontal line is being scribed on the display screen.

I solved this problem by designing the flip-flops of the ripple counter to be quite fast (using MPSH10 transistors) and conversely designing and (N)AND gates for decoding to be only adequately fast for the application, rather than excessively so, such that the decoders are too slow, by a comfortable margin, to respond to and pass through the erroneous binary states of the counter during the ripple-through of the clock.

The DTL (diode-transistor-logic) N(AND) gates are made "slow" by using comparatively-lowly BC550C transistors with a relatively weak base pull-up. The AND gates that provide the horizontal video signals for generating the scoreboard display digit segments are comprised of a BC550C NAND followed by an MPSH10 DTL inverter. The through-put propagation delay of this combo is a clean and stable ~120nS and the MPSH10 inverter provides (in addition to the required polarity inversion) a squared-up output with fast rise and fall times.

The MSB (HR16) of the horizontal ripple counter is at the line frequency (15,625 kHz) and it is used as the clock source for the vertical line counter. The horizontal video component of the paddles and the court net are approximately 600nS wide and 300nS wide respectively. As this is substantially less than the 2uS master clock period, these video signals are produced by triggering high-speed monostables.

All of the signal outputs of the horizontal timing unit are digital, bar "H_SCAN", an analogue line-scan ramp signal. H_SCAN is provided for the Ball Horizontal Movement circuit.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308145;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308147;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308149;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308151;image)

The board itself. I currently have a rather crappy ferrite-cored "choke" with a rather poo temperature coefficient soldered into the tank circuit of the master oscillator, as this is what immediately at hand. I'll will be sourcing a better core material to wind a better substitute. 

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308153;image)

Damn, you've been busy GK! I have a feeling I won't be able to fit this project all on a single large board... It looks like it's going to be *a lot* of parts! :D

(Though laying out a PCB for this project should be *a lot* faster as my library is already mostly setup and I've learned a lot so far doing the Scope Pong board.)

Speaking of which, I'm hoping to have the first revision of Scope Pong done by week's end.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 15, 2017, 01:44:03 am
There were some computer monitors that would blow the horizontal output transistor or other parts if they were fed an incompatible sync signal, but most would tolerate it at least for a while.


They must be rare examples of crap/cheap design.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 15, 2017, 02:24:13 am
With the worst possible +/- 2khz error on the 500khz resonator I listed, GK's H sync generator would be from 15.562-15.625-15.6875Khz.  The error doesn't even make it to NTSC's 15.734k.  For B&W, the listed resonator is a safe cheap 0.7$ reference which wont destroy any monitors at all and would probably drop into his current circuit with ease.  He could even cheapen it up with a 2 transistor oscillator instead of the current 6 if he likes.  Just accidentally touching a point with your finger on the inductor tuned oscillator will go way further out of bounds.


I didn't claim that an equivalent resonator oscillator would be less stable or accurate than an LC one. Re the design involving those 6 transistors - the LC oscillator requires a frequency trim and you can't get 1nF trimmer capacitors. I biggest I could get at the local Jaycar last week afternoon was 8.5-100pF. I put that in parallel with 150pF and that still gives me adequate range to trim for the inductor tolerance. To get down to 500 kHz with ~205 pF a 470uH inductor is required. This is a poor LC ratio for a typical basic oscillator design as the inductance is large and the capacitance is small. For these values XL=XC=~1500 ohms at 500 kHz, so in an idea case restive loading of the tank circuit must be ~15k for an tank circuit Q of just ten, but in reality higher as the resonate Q is lowered further from the ideal, in this case primarily by the inductors non-zero series resistance.

The Darlington-connected input transistors present a high impedance load to the tank circuit maintaing Q. The high input impedance also helps preserve Q by permitting positive feedback to be lightly coupled (via 47k) to the tank circuit with minimal loop-gain attenuation. The Darlington transistor pair connected in a long-tail pair double operates as a limiting amplifier, giving a squared-up and stable amplitude of oscillation, further aiding stability. The first high-speed toggle flip-flop of the horizontal ripple counter requires a clock source of adequate amplitude and rise/fall dv/dt. This is provided by the second long-tail-pair limiting amplifier, bringing the total transistor count to six.

The whole purpose of this design exercise is to construct and demonstrate something more impressive than a LED-blinkie with rudimentary components. For a high frequency clock source they don't get much more rudimentary than a trimcap and a non-specialized, non-custom inductor.
     
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mfratus2001 on April 15, 2017, 05:02:09 am
Not to distract you, but I used to have a few Pong game boards from some company, and one worked. I tried to fix the other ones, and started reverse-engineering it. It had lots of 4066 (or 4016's) analog switches. One switch must have been bad because the ball would launch from one side and slowly get lower and lower as it went back and forth. Never did fix it... life went on. Great project there, very retro. Needs to go into an old Apple-II case!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 15, 2017, 08:20:25 am
With the worst possible +/- 2khz error on the 500khz resonator I listed, GK's H sync generator would be from 15.562-15.625-15.6875Khz.  The error doesn't even make it to NTSC's 15.734k.  For B&W, the listed resonator is a safe cheap 0.7$ reference which wont destroy any monitors at all and would probably drop into his current circuit with ease.  He could even cheapen it up with a 2 transistor oscillator instead of the current 6 if he likes.  Just accidentally touching a point with your finger on the inductor tuned oscillator will go way further out of bounds.


I didn't claim that an equivalent resonator oscillator would be less stable or accurate than an LC one. Re the design involving those 6 transistors - the LC oscillator requires a frequency trim and you can't get 1nF trimmer capacitors. I biggest I could get at the local Jaycar last week afternoon was 8.5-100pF. I put that in parallel with 150pF and that still gives me adequate range to trim for the inductor tolerance. To get down to 500 kHz with ~205 pF a 470uH inductor is required. This is a poor LC ratio for a typical basic oscillator design as the inductance is large and the capacitance is small. For these values XL=XC=~1500 ohms at 500 kHz, so in an idea case restive loading of the tank circuit must be ~15k for an tank circuit Q of just ten, but in reality higher as the resonate Q is lowered further from the ideal, in this case primarily by the inductors non-zero series resistance.

The Darlington-connected input transistors present a high impedance load to the tank circuit maintaing Q. The high input impedance also helps preserve Q by permitting positive feedback to be lightly coupled (via 47k) to the tank circuit with minimal loop-gain attenuation. The Darlington transistor pair connected in a long-tail pair double operates as a limiting amplifier, giving a squared-up and stable amplitude of oscillation, further aiding stability. The first high-speed toggle flip-flop of the horizontal ripple counter requires a clock source of adequate amplitude and rise/fall dv/dt. This is provided by the second long-tail-pair limiting amplifier, bringing the total transistor count to six.

The whole purpose of this design exercise is to construct and demonstrate something more impressive than a LED-blinkie with rudimentary components. For a high frequency clock source they don't get much more rudimentary than a trimcap and a non-specialized, non-custom inductor.
   
Would an RC osc be significantly less stable ? Maybe a phase-shift osc?
The trimmer value issue shouldn't be a major problem as you  can shunt it with fixed caps to get within the required trim range.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 15, 2017, 02:02:21 pm
Would an RC osc be significantly less stable ? Maybe a phase-shift osc?
The trimmer value issue shouldn't be a major problem as you  can shunt it with fixed caps to get within the required trim range.


An RC relaxation or phase-shift oscillator oscillator would be a lot less stable. You won't find them in preference to LC oscillators in your AM radio.
I think you misunderstand about the trimmer capacitor value; if the inductor tolerance is +/- 20% and the biggest practical trimmer you can get is ~100pF then you simply can't bung a couple of nF in parallel to get an adequate, high-Q L-C ratio at 500 kHz because you then won't have enough trim range - unless you plan to S.O.T maybe multiple padding capacitors.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 15, 2017, 02:34:33 pm
Okay, made some very satisfying progress this evening. I got half of the scoreboard video segment decoder array soldered up onto the half-a-board of empty space remaining on the Vertical Timing board. This means that I can now generate a video display with player 1's score counter digits displaying on the scoreboard.

One thing that I was aware of and initially resigned to just living with is that because of inevitable and non-zero propagation delays through my horizontal ripple counter, the decoder circuitry and gate array, is that the generated digit segments would not all align 100% perfectly. Exactly how much of a visual impact this would have wasn't of course tested until now.

The first picture attached below shows the initial result. Well, not too bad at all and I guess a perfectly acceptable degree of quality for a display generated entirely with discrete transistors and diodes, right?

Well I stared at the screen for about 30 seconds and decided NO!. I suddenly remembered that I still had stashed under my bench the prototype discrete-transistor (again MPSH10) master-slave, pure-edge-triggered delay flip-flop (DFF) that I built as an evaluation piece for my 16-bit processor project. I described this DFF previously in reply #12 here:   https://www.eevblog.com/forum/projects/homebrew-digital-computer-system/msg460596/#msg460596 (https://www.eevblog.com/forum/projects/homebrew-digital-computer-system/msg460596/#msg460596)   

So, I switched off power and pulled the scoreboard video logic signal wire from the breadboard and wired it to the D-input of my DFF instead. I modified my clock oscillator buffer to provide complementary (out of phase) clock signals. One for the horizontal timing circuit ripple counter and the other exclusively for the clock input of my DFF. So now I have a DFF clocked half a period (1uS) out of phase with my video generator circuitry. This 1uS is ample time for all of my horizontal counting flip-flops to ripple-through and the decoding to settle. The Q output of my DFF is now the scoreboard video signal, delayed by half a clock cycle, rather than sent to the screen live. The DFF effectively operates as a memory cell/buffer. This is data deskewing, boys and girls.

The second attached picture shows the result - perfectly aligned digit segments. Yoo hoo! This project is slowly evolving into one of the more satisfying things I've built in a while. The third attached picture shows the complete set up as it currently sits. The circuitry on the bread board is just a couple of discrete N(AND) gates, a resistor matrix and a 75-ohm-zout emitter-follower buffer to combine the discrete logic-level video, blanking and sync signals into the one composite video signal. 

As it currently stands, there are 107 individual transistors gating electrons. Considering what has been achieved so far for a video image, I don't think that is too bad at all  :D

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308486;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308488;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308490;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 15, 2017, 03:08:34 pm
Damn, you've been busy GK! I have a feeling I won't be able to fit this project all on a single large board... It looks like it's going to be *a lot* of parts! :D

(Though laying out a PCB for this project should be *a lot* faster as my library is already mostly setup and I've learned a lot so far doing the Scope Pong board.)

Speaking of which, I'm hoping to have the first revision of Scope Pong done by week's end.


Yeah, I think you'd have difficulty fitting it onto single board of practical size. This would be a contender for all-SMD construction, I think. The MPSH10 transistors in any case have been obsoleted in the TO-92 case (I have a big stash just for me though  :P).

The transistor count so far isn't too bad though; I've got most of the logic completed and am still way short of the transistor count of the oscilloscope version - but the analog paddle generation and ball movement, sound and colour-video encoding circuits are going to reverse that situation before long.......

I am, admittedly, feeling a tad immodestly-full of myself this evening.....

Seriously now, am I just f%$@ing awesome or what?  ;D   

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 15, 2017, 04:40:37 pm
I am, admittedly, feeling a tad immodestly-full of myself this evening.....

Seriously now, am I just f%$@ing awesome or what?  ;D   

Hmmm, not sure. Maybe we need to take a poll or something. LOL! :-DD
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 15, 2017, 05:52:01 pm

Damn, you've been busy GK! I have a feeling I won't be able to fit this project all on a single large board
Vertical resistors & diodes ?
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 15, 2017, 07:28:31 pm

Damn, you've been busy GK! I have a feeling I won't be able to fit this project all on a single large board
Vertical resistors & diodes ?

Yeah, that's an option I suppose, but I've always hated kits that do that for some reason. It's a PITA to insert and solder plus it makes it a lot harder to probe. (I've also always felt vertical mount resistors and diodes are a lot easier to damage or something; though I have no proof if that's true or not.)

Anyway, since this would be a more advanced kit, I'm thinking SMD might be the way to go (since the higher end transistors are only available in SMD anyway it would make sense). I could use 1206 or larger parts, to make it fairly easy to hand solder.

Another thought is to break each section onto its own board and then have a backplane board with edge connectors and the power supply on it. That way everything would still be easily visible for display purposes and easy to access and service. Most Chinese board houses will do gold fingers for a couple of bucks, so it's doable.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 15, 2017, 08:27:33 pm
For hand soldering, 0805 isn't really any harder than 1206, though 1206 does allow for more tracks to be jumped over.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 15, 2017, 08:56:43 pm
For hand soldering, 0805 isn't really any harder than 1206, though 1206 does allow for more tracks to be jumped over.

Yeah, that was my thought. Since it'll likely be two layers, being able to route under components is a big plus!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 15, 2017, 09:53:53 pm
Also on a home made board without a solder mask, with even 1 trace under an 0805 could potentially solder short without one knowing it.  1206 is the safer choice and you can keep relatively thick traces.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 15, 2017, 10:52:46 pm
Also on a home made board without a solder mask, with even 1 trace under an 0805 could potentially solder short without one knowing it.  1206 is the safer choice and you can keep relatively thick traces.
True, but is anyone seriously going to bother homebrewing a PCB that complex when you can get proper PCBs so cheap?
And for a SMD board, there would be a lot of through-links, and allowing for homebrew would mean you couldn't put any vias under components.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 15, 2017, 11:10:11 pm
Seriously now, am I just f%$@ing awesome or what?  ;D   
Ok.
Now you've done it...
Once this is completed,
I am expecting to see you do a multi-ball with an XY thrust style movable player avoidance game,
or,
a center stationary player aim and shooting multiple bouncing balls which will deflect them away as they also bounce off the screen boundaries only to eventually head back at you.

Either, or, sort of the building a part of something like an all transistor asteroids.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 16, 2017, 12:05:03 am
I've been thinking about a vector game such as asteroids in some form or another for a little bit now. I've already built the CRT X-Y display after all:
https://www.eevblog.com/forum/chat/show-me-some-cool-stuff-you've-made!/msg1127985/#msg1127985 (https://www.eevblog.com/forum/chat/show-me-some-cool-stuff-you've-made!/msg1127985/#msg1127985)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 16, 2017, 12:32:06 am
Looking at your pong layout, I was thinking along the lines of a base unit, clock generators, sound generator, with a 16 channel xyz(RGB) analog switch network going to 16 edge card connectors.  Each card connector will have the x,y,z(RGB) & all audio tone fx channel ena & cross x/y position of each channel for collision detectors + x1/y1 fire1, x2/y2 fire2, global reset, global start input on each board.  Each board will basically be a programmable sprite, all identical, with a few jumpers to configure function.

Remember you wanted to make your ultimate +/-100v analog computer, instead, this would be your ultimate, configurable all transistor video game console.

You may also change the base unit for a raster interpreter version later on.  I would still recommend 480p/720p RGB VGA, VGA to HDMI converters are only 10$ which include stereo audio line input in stereo so you can see and hear on any TV today, in progressive 60hz HDTV.

Kind of shocking that these games would work in the 1960s...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 16, 2017, 08:00:07 am
Also on a home made board without a solder mask, with even 1 trace under an 0805 could potentially solder short without one knowing it.  1206 is the safer choice and you can keep relatively thick traces.
True, but is anyone seriously going to bother homebrewing a PCB that complex when you can get proper PCBs so cheap?
And for a SMD board, there would be a lot of through-links, and allowing for homebrew would mean you couldn't put any vias under components.

That's my thought too. Going all SMD there would be so many vias I couldn't really see anyone ever etching one by hand, especially when you can order a PCB so cheap from China.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 16, 2017, 11:22:43 am
An additional 9 transistors soldered in and the scoreboard readout is complete. The gate array for the scoreboard digital readout is just a 3-input DTL NAND gate for each segment, all with the open-collector outputs tied together and thus ORed.

For each NAND gate, one of the three inputs is fed the vertical video component for the respective segment whilst the second of the three inputs is fed the horizontal video component. The third input is the control line to switch the respective segment OFF. The inputs of the DTL NAND gates default high courtesy of the resistive pull-up, so all of the segments, with the control inputs left floating, default ON.
The decimal outputs of the player score counters will be active-low, open-collector-outputs, asserting the NAND gate control inputs via a simple diode array performing the decimal to seven-segment decode. Doing it this way (turning the segments OFF rather than ON) saves 24 diodes in the decoding array and is a natural fit to the operation of the DT-logic.

After dinner I'll solder up the last remaining circuit block of the Vertical Timing board in the remaining board space; this being the V_SCAN vertical ramp generator, which is identical to the horizontal one, just with a different time constant. The V_SCAN ramp is required for the Ball Vertical Movement circuit and also the Paddle movement circuits. I intend to build the paddle video generation and control/movement circuits tomorrow.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308644;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=308646;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 16, 2017, 01:57:38 pm
The complete Vertical Timing circuitry. Unlike the horizontal, there aren't any high speed switching requirements here so it's all just BC550C for the switching stuff.

EDIT: schematic updated 25/April/17

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 17, 2017, 04:01:58 am
Kind of shocking that these games would work in the 1960s...


That's a kinda interesting thought. High speed switching transistors already existed in the 50s in large part due to digital computer development. From a technical standpoint only, Arcade Pong wouldn't have needed to wait for the development of integrated TTL. The circuit I am building here could have been built ~60 years ago; probably would have required a fairly well-to-do hobbyist though as bleeding-edge transistors were fairly pricey back then, I'm fairly sure. 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 18, 2017, 11:01:42 am
Okay guys, so I went back to work on the Scope Pong board last night, but I'm starting to think maybe going with two 250x250mm boards (versus one large 250x400mm board) might actually be a better idea.

Now that I'm finally laying out the Ball Vertical & Horizontal Movement sections I'm finding it increasingly difficult to interconnect all the various sections over such a large board. I'm thinking it would be *a lot* easier with two stacked boards, because I could use 2.54mm headers to drop the signals close to where they need to go, right from one board to the other (instead of having to run 500mm of trace plus multiple vias). The Function Gen, Multiplexer Logic & Drive, Output Amps, Reference Regulator, Power Supply and Audio Amp would all be packed on one board, with the Velocity Integrator, Ball Vertical Movement, Paddle Collision and Audio Generation stuff on another. (The second board wouldn't be packed as densely to allow room for routing traces to the correct locations over/under the first board.)

Though I'm still not completely giving up on a single board just yet. I want to try and rearrange some existing sections (and possibly split one up) first to see if I can make it work. I just wanted to give a status update and get any thoughts on this first. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 18, 2017, 11:20:33 am
Can you give us a look?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 18, 2017, 11:30:41 am
I think a large PCB will have a lot more visual appeal, and for a 'novelty' thing like this, I think that's pretty important.
Is it much of a deal if you have to (neatly) run a few wires or long jumper links?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 18, 2017, 12:05:12 pm
^^^ Yes, give us a look.


--------------------------------------------------------------------------

On the Raster Pong front, I haven't made the progress I wanted the past couple of nights, but I've now got one movable Paddle displayed on the screen and almost all of the circuitry to display the other done.

It's starting to get away from the boring digital and more into the analogue now  :). The paddle movement is done by a comparator that compares the potential at the wiper of the paddle position control potentiometer with the V_SCAN ramp. When the amplitude of V_SCAN exceeds the wiper potential an RS flip-flop is set. This flip-flop is reset at the end of the frame scan by the vertical sync pulse. The purpose of this flip-flop is to ensure that only a single triggering of the proceeding monostable can occur each frame; said monostable being triggered by the flip-flop once set.
The monostable generates a pulse that is the vertical component of the paddles video signal. The output pulse duration of the monostable is potentiometer-variable over a 4:1 range, so that the size of the paddle can be varied. For example if the pulse width is 2000uS, the paddle will have an on-screen height of 2000/64 = 32 horizontal lines.

The full vertical movement of the paddle extends off the screen (at the top it disappears behind the scoreboard). The pictures below show the paddle at three different positions and the monostable output (paddle vertical video signal) in relation to the V_SCAN ramp can be seen simultaneously on the oscilloscope screen.

The monostable circuit is a bit of an elaborate affair as has to provide a second output for the collision detection. My Rigol only has 2 channels, but I saved two separate screenshots made with a common trigger source and assembled in MS Paint to show three traces. This is attached below. Yellow is V_RAMP, blue is the paddle vertical video pulse and red is the second pulse output of the monostable. This pulse is always 1/3 the duration of the paddle vertical video pulse and positioned directly in the center. It represents the middle section of the paddle. When a collision is detected between the ball and the paddle, the logic level of this second output at the instant of collision will determine the setting of a flip-flop which sets the balls angle of deflection. If the ball hits the center of the paddle it will bounce off at 45 degrees, if not, meaning a collision occurred with the extremities of the paddle, then the ball bounce off at 67.5 degrees.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309067;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309069;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309071;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on April 18, 2017, 07:39:23 pm
I think a large PCB will have a lot more visual appeal, and for a 'novelty' thing like this, I think that's pretty important.
Is it much of a deal if you have to (neatly) run a few wires or long jumper links?

+1

Also, over time (years), board interconnections tend to be a weak point as regards reliability/longevity.

Having stacked PCB's can make it considerably harder to fix/test, assuming they are stacked vertically. I.e. when the construction fault(s) are on the harder to access, lower board.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on April 18, 2017, 08:07:27 pm
It depends on how they're stacked. If they used something like a single or dual row 0.1" header/socket then it would be easy enough to make a cable for troubleshooting or if you wanted to put the boards side by side. Personally I think a single board has more appeal but I could go either way really.

The prototypes have got to be the most ridiculously neat and tidy dead-bug constructed projects I've ever seen. They look amazing, and it's great to see somebody still doing this kind of clever analog design instead of just throwing a microcontroller at it.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 18, 2017, 09:58:20 pm
clever analog design instead of just throwing a microcontroller at it.
Forget microcontroller, he isn't even using a logic IC or even an OP-Amp.
BTW, the design isn't all analog, he does after all now have at least 1 D-Flip-Flop, ripple counter/clock dividers, ect... though he constructed all of them with transistors, diodes, caps and resistors from the ground up.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 18, 2017, 10:02:17 pm
GK, I have a question about your Flip-Flop which you used to clean the pixels on your display.  Is it a regular positive edge triggered device similar to a 74LS74, or, did would it have been possible to use a sample-and-hold trick using a j-fet as an analog gate switch with a second one as a follower buffer?  Sort of like a transparent latch used in some data buss buffers.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on April 18, 2017, 10:40:05 pm
@TimB
If possible I would prefer a single board or 2 boards that can sit side by side without a huge ribbon cable covering them.
In other words the aesthetics of this project is important for me.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 18, 2017, 11:29:28 pm
 Okay then, I guess it stays a single board! :) One way or another we'll make it work.

I'll post a PDF later with the current layout. I want to draw some ratlines on it first to show you guys the major nets that need to be connected.

Another thing I was thinking is, currently I've got a 16 position terminal block for the Paddle 1/Paddle 2 Inputs and the Rotary Switch connections, however I could split it up and decrease it to 9 positions by making the user wire some of the connections together at the switch instead of doing it on board.

By this I mean, P1/P2 selection is done with a DP4T rotary switch which, for example, has Ball-Y fed to connections 1&3 of Pole 1 and 1&2 of Pole 2. Right now I simply have a terminal block with 10 connections so the user can wire the switch straight into the board and I take care of making sure Ball-Y gets to the correct switch terminals, however it would be a lot easier on me if I could have a single terminal block with a Ball-Y output and let the user jump terminals P1.1, P1.3, P2.1 & P2.2 together with wire and run the Ball-Y connection to one of them. Make sense?

In this case I would have a single +15V and -15V connection (right now there's two of each, one for each paddle but they could obviously be shared). Then I'd have an input for each paddle which goes through the RC network, an output for each paddle and Ball-Y, which goes to the rotary switch, and finally an input from the common on both poles of the rotary switch.

This would actually give me quite a bit of freedom to re-arrange things, as I could put several of the terminal blocks in different locations, so I don't have to run some of the traces halfway across the board.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 18, 2017, 11:50:45 pm
I don't think having wires coming to the PCB in various places is a big deal, as long as they are at the edge, so those concerned with aesthetics could do them as a nice loom.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 19, 2017, 04:56:49 am
Okay then, I guess it stays a single board! :) One way or another we'll make it work.

This would actually give me quite a bit of freedom to re-arrange things, as I could put several of the terminal blocks in different locations, so I don't have to run some of the traces halfway across the board.
2 or 3 banks of terminal blocks are perfectly fine.  Might be even better for design visualization.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on April 19, 2017, 08:31:52 am
I'm thinking of breaking out some of the waveforms to be displayed on a separate CRO.
TimB said he would putting in a few test points so I guess I could use these. 

My goal is to make an exhibit that could be used to get people interested in electronics.
I have plenty of old scopes to throw at it.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 19, 2017, 10:02:09 am
Okay then, I guess it stays a single board! :) One way or another we'll make it work.

This would actually give me quite a bit of freedom to re-arrange things, as I could put several of the terminal blocks in different locations, so I don't have to run some of the traces halfway across the board.
2 or 3 banks of terminal blocks are perfectly fine.  Might be even better for design visualization.

So this is what I came up with:

(http://timb.us/Projects/Scope_Pong/Mode_Switching.png)


And here's a PDF of the layout with some colored ratlines added to show the nets that need connecting:

http://timb.us/Projects/Scope_Pong/Layout_20170419_Markup.pdf

Note that the position of the top three blocks (outlined in blue) are still up in the air as they're all still under construction (I may push the Paddle block over to the far left and move the Ball Movement blocks towards the right). I'm also thinking I can rotate the Velocity Integrator (top left) block 90 degrees to the left and push it more towards the edge of the board. I'm also going to re-arrange the monostable timers of the sound generator (bottom right). Finally, the Function Gen section can be rotated 90 degrees to the right and pushed into the little gap between the Multiplexer Logic and the top of 5 bit flip-flop array.

I spent most of the night flipping, rotating and moving stuff around tonight to try and get a more streamlined layout and most of the above should help. The big trouble is in getting the + and - Ref lines everywhere they need to go and getting the three trigger lines to the sound circuitry.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on April 19, 2017, 11:48:11 am
Hi GK,

Could you post a hi res photo of your oscilloscope pong board. I think it would be amazing to look at, as well see your build technique.

Thanks,
Gary
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 19, 2017, 11:48:27 am
GK, I have a question about your Flip-Flop which you used to clean the pixels on your display.  Is it a regular positive edge triggered device similar to a 74LS74, or, did would it have been possible to use a sample-and-hold trick using a j-fet as an analog gate switch with a second one as a follower buffer?  Sort of like a transparent latch used in some data buss buffers.


It's negative edge-triggered, but there is a simpler incarnation made up of less NAND gates that I posted further on in the digital computer thread. Some kind of logic-level S&H could be made to work no doubt, but I think I'll stick to the 6xNAND gate DFF.

Incidentally I just got back in from the shack. It's getting on to 9PM now and I really should have had dinner first, but I just couldn't wait; the colour theory has been buzzing around in my head all day and I just had to breadboard my test circuit to make sure I have the theory down pat. Looks like I have. The circuitry is as quick and crude as I could get away with and I had to fiddle a fair by with grounding and bypassing to get a stable colour-locked picture that wasn't full of noise as the breadboard assembly is far from ideal; the chromoa circuitry is on the far-right breadboard in the photo. The 17.73 MHz (x4) chroma frequency reference comes from my Rigol sig.gen..
The picture quality still isn't great, but there is not much scope or point in further improvement with this breadboard prototyping.   

I designed for an injection/summation of RED chroma components over the luma component of the scoreboard. As you can see the circuitry is discrete CMOS logic, but this is just a quick concept/theory verification for now. Tomorrow I'll make sure I've got the sums right/in the ballpark for the other desired display colours and re-wire the test circuit for each accordingly. After that I'll be in a position to start soldering together and wiring in stage-by-stage the fully discrete substitute. But it's dinner, shower, bed for me now unfortunately.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309277;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309279;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 20, 2017, 12:34:21 pm
Hi GK,

Could you post a hi res photo of your oscilloscope pong board. I think it would be amazing to look at, as well see your build technique.

Thanks,
Gary


OK, try these:

http://www.glensstuff.com/pong/pong1.jpg (http://www.glensstuff.com/pong/pong1.jpg)
http://www.glensstuff.com/pong/pong2.jpg (http://www.glensstuff.com/pong/pong2.jpg)
http://www.glensstuff.com/pong/pong3.jpg (http://www.glensstuff.com/pong/pong3.jpg)
http://www.glensstuff.com/pong/pong4.jpg (http://www.glensstuff.com/pong/pong4.jpg)
http://www.glensstuff.com/pong/pong5.jpg (http://www.glensstuff.com/pong/pong5.jpg)
http://www.glensstuff.com/pong/pong6.jpg (http://www.glensstuff.com/pong/pong6.jpg)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 20, 2017, 12:36:03 pm
An additional 9 transistors soldered in and the scoreboard readout is complete. The gate array for the scoreboard digital readout is just a 3-input DTL NAND gate for each segment, all with the open-collector outputs tied together and thus ORed.

For each NAND gate, one of the three inputs is fed the vertical video component for the respective segment whilst the second of the three inputs is fed the horizontal video component. The third input is the control line to switch the respective segment OFF. The inputs of the DTL NAND gates default high courtesy of the resistive pull-up, so all of the segments, with the control inputs left floating, default ON.
The decimal outputs of the player score counters will be active-low, open-collector-outputs, asserting the NAND gate control inputs via a simple diode array performing the decimal to seven-segment decode. Doing it this way (turning the segments OFF rather than ON) saves 24 diodes in the decoding array and is a natural fit to the operation of the DT-logic.


And here it is (continuing with the documentation):

EDIT: schematic updated 25/April/17

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310718;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 20, 2017, 12:43:54 pm

Incidentally I just got back in from the shack. It's getting on to 9PM now and I really should have had dinner first, but I just couldn't wait; the colour theory has been buzzing around in my head all day and I just had to breadboard my test circuit to make sure I have the theory down pat. Looks like I have. The circuitry is as quick and crude as I could get away with and I had to fiddle a fair by with grounding and bypassing to get a stable colour-locked picture that wasn't full of noise as the breadboard assembly is far from ideal; the chromoa circuitry is on the far-right breadboard in the photo. The 17.73 MHz (x4) chroma frequency reference comes from my Rigol sig.gen..

That circuitry reminds me of the BBC Micro colour encoder ( bottom right)
http://mdfs.net/Info/Comp/BBC/Circuits/BBC/bbc.gif (http://mdfs.net/Info/Comp/BBC/Circuits/BBC/bbc.gif)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on April 20, 2017, 12:45:53 pm
One thought re.  size of a SMD PCB of the video version - there are a lot of diode pairs, so dual SOT-23 diodes would save quite a few components.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 20, 2017, 01:00:30 pm
That circuitry reminds me of the BBC Micro colour encoder ( bottom right)
http://mdfs.net/Info/Comp/BBC/Circuits/BBC/bbc.gif (http://mdfs.net/Info/Comp/BBC/Circuits/BBC/bbc.gif)


Yep, as mentioned previously, that is my design inspiration. Simply by independently toggling the polarities and varying the amplitudes of my U and V I can make any pretty colour I can care for.

I'm quite chuffed with how easy it has turned out to encode colour, and how reasonable it's possible to get the quality of the picture with such a crappy and quick breadboard implementation/experiment. Can't wait to get the properly designed fully-discrete-transistor incarnation done to find out how much better the picture quality will be. If you go to bed for a few nights on end with a copy of the BBC Micro service manual and W C Cook's PAL Colour Television For Servicemen, this is what happens  ;D

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309582;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on April 20, 2017, 06:57:25 pm
I'd have expected that to be much more difficult.

Ok now try to do NTSC color :)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 20, 2017, 11:26:31 pm
I'd have expected that to be much more difficult.

Ok now try to do NTSC color :)

I actually looked into how hard it would be to add PAL to NTSC support circuitry onto the board. It's hard. There used to be ICs to do that sort of thing, but they're all long depreciated. Looking into the block diagrams of them I figure it would take hundreds of discrete components to replicate and just wouldn't be worth it.

I then looked into PAL to HDMI. It's doable, but would require two main ICs (a "Universal Analog Video to BT.656 Converter" and a "Intermediary Digital Video to HDMI Transmitter") plus a handful of support components (a PLL, 3V3 regulator, basic MCU to setup the converter chips over SPI or I2C, some buffers, etc.) and that's just for video! You still have to break the audio out of the PAL feed separately and run it into an A to D with a PCM SPDIF (or DTS I2S) output. (Though you don't need a separate chip to the transmit the audio once it's in SPDIF or I2S as the HDMI video transmitter chip can take care of that.)

It's a lot of work, to put it mildly. You'd think some company would make a single chip NTSC/PAL/SECAM Audio/Video to HDMI solution, but they don't.

I think the best bet is to stick with a $20 Analog to HDMI box for running it on modern LCD or Plasma. If you want to run it on an old CRT Monitor get a Analog to VGA converter. You can also buy old PAL to NTSC converters on eBay for cheap if you want to use a CRT TV.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 21, 2017, 12:16:36 pm
I'd have expected that to be much more difficult.

Ok now try to do NTSC color :)


I'm fairly sure, concerning the chroma only, converting to NTSC would just require disabling the PAL flip-flop and switching a different frequency subcarrier oscillator.
This circuitry isn't very complex as chroma components for only a few individual colours need be generated. Basically all you need to do is generate and inject your quadrature U and V; the polarity (phase) and amplitude of each is what determines the colour, and these can be computed from some basic equations. No need for mixers/modulators or any of that stuff.   

I made some very satisfying progress today - the prototype chroma encoder using that breadboard and those despicable integrated circuits has been dispensed with and substituted with a fully discrete circuit; I've now got vivid colour and it's back to discrete transistors only! And with the refinement of the design and a tidying up of the wiring and the dispensing of the breadboard, the picture quality has been very much improved. It is still suffering a bit due to noisy grounds on the remaining breadboard currently sporting the luma circuitry and video buffer, but I'm getting there.   

As the circuit was somewhat experimental and was modified and refined throughout the course of the day, I built it dead-bug with little care for neatness on an old and very tarnished square of copper laminate that I had handy; this isn't the final build, just a prototype and it currently doesn't have duplicate circuitry for gating any colour other than red. So the R&D for the colour encoding part of this project is now over and the electronic design is now complete. The next stage will be to build up the complete combined luma and chroma processing circuitry in its final form on a fresh, lacquered slab of blank PCB.

I won't have time this evening to draw up the schematics in a presentable form, so it's just some pretty photos for now. The success of my chosen method of implementing the quadrature "carriers" hinged on producing a discrete toggle flip-flop (of which three duplicates are used) that can happily toggle at 17.73 MHz and still give clean and usable squarewave outputs. I was obviously successful here and my flip-flops better the required performance by a rather comfortable margin, but I had to dig into some rather old and arcane design here!

Oh, and yeah, my Commodore 64 kindly donated the 17.73 MHz crystal (only temporarily, until my Mouser order arrives)  ;D

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309871;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309873;image)
 
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309875;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 21, 2017, 12:24:30 pm
Did you also order the 500KHz resonator from Mouser as well?  I believe they had stock.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 21, 2017, 03:46:29 pm
Oh, no, I didn't even think of it to be honest. I lied about scribbling a circuit diagram of the chroma circuit this evening. I realised that my fully-discrete proto didn't sport an inverter for V, and you need NOT-V to do green, so, not being able to help myself I went back into the shack and soldered up another MPSH10, flipped to NOT-V to check the green and then decided to redraw/scribble up the schematic too. And now I am typing post 1am - so much for my plan yet again for an early night  ::) The schematic shows everything except for the U/V gating for the desired colours, but this is just, for each desired colour, a duplication of the circuitry shown in the lower left of the schematic for gating the colour burst, with the difference being that the U/NOT-U & V/NOT-V inputs are instead hardwired as required for the desired colour and the mixing resistors values are chosen for the required signal amplitudes respectively, and the gating input signal is a video signal line.

Three high-speed toggle flip-flops do the quadrature encoding. The first TFF divides the 17.73 MHz clock down to 8.865 MHz. The other two high-speed TFFs each divide the first TFF's output down to the 4.43 MHz chroma carrier frequency in parallel, except that one is clocked by the first TFF's Q output and the other by the NOT-Q output; hence the two 4.43 MHz clocks thus produced are 90 degrees out of phase. One "issue" with this simple arrangement, constructed from practical discrete-transistor TFFs, is that, depending of which initial state the TFFs assume upon power up, one of those 4.43 MHz quadrature signals might be leading the other or it might be lagging. It's essentially a random thing, but for PAL, this doesn't matter at all as the V signal is flipped 180 degrees in phase every second line and the receiver establishes its reference from the colour burst. Cool huh? I think I spent about one third to half a day pondering in the back of my mind (whilst doing boring stuff at work) how to overcome this design issue before finally realizing (DUH!) that it isn't an issue at all.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309915;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=309917;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 22, 2017, 04:21:14 am
I'd bet good money if you replaced your 17.73 Mhz crystal with 14.31818Mhz (NTSC standard crystal) divide by 4 for 3.579545 MHz and had a jumper to limit your vertical counter to 262 or 263, though the text image would be stretched, your existing circuit would work on a NTSC display.  You might need to increase your vertical location ramp oscillator to adapt the paddle/ball positions and size.  Only your chosen colors may be different, but, they would still work.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 22, 2017, 02:27:03 pm
Probably, but still not persuaded. I made a start on the score counters late this afternoon. So far I've completed the BCD-to-binary and the binary-to-7-segemnt decode logic and have one of the BCD counter toggle flip-flops installed. The rest of the TTFs along with the associated control logic will run along the bottom of the board. On the right hand side besides the decoders I should have enough room to solder up the DFF for deskewing the scoreboard video signal and hopefully enough after that for an additional decoder I've decided to add to provide an additional video signal producing a bottom boundary for the ball play area.

I hope it doesn't detract from my mystique as a serious dead-bugger, but I wimped out a bit here and made things easier on myself by cutting up some veroboard to support the diode arrays performing the decoding  ;D.

The printed circuit diagram is of my LTspice score counter circuit simulation - it almost quicker to draft complete ideas in LTspice than to draw by hand.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310092;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Mukrakiish on April 22, 2017, 03:42:39 pm
Wow, your work is just so damn pretty. Not sure how it works but man does it ever look good doing what it does!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 22, 2017, 07:20:56 pm
I hope it doesn't detract from my mystique as a serious dead-bugger, but I wimped out a bit here and made things easier on myself by cutting up some veroboard to support the diode arrays performing the decoding  ;D.
That is very cool Glen, in fact that's probably the wisest layout for the arrays. Very classy.  :)
I particularly like how you've used decoupling caps as standoffs on the long runs of wire.  :-+

Massive respect for your ingenuity and perseverance.  :clap:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 23, 2017, 01:03:47 am
I hope it doesn't detract from my mystique as a serious dead-bugger, but I wimped out a bit here and made things easier on myself by cutting up some veroboard to support the diode arrays performing the decoding  ;D.

That's still dead bug, just that it's a dead bug on a few elevated tables...
Once again, impressive as hell...  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 23, 2017, 10:59:41 am
Damn, that is pretty GK! :D

So, I've got one section (Paddle Collision) left to finish on the Scope Pong board. Once I finish that I've then got to route all interconnections together, do some cleanup and I'll be done. Hopefully in the next day or two.

I've also been working on a prettified "Theory of Operation" document to go along with the actual schematics. Here's a preview of how the graphics are shaping up:

(http://timb.us/Projects/Scope_Pong/Scope_Example.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 23, 2017, 12:25:22 pm
Would it be wise to add 0V markers for each of the traces on the oscillograph ?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 23, 2017, 01:35:29 pm
That is very cool Glen, in fact that's probably the wisest layout for the arrays. Very classy.  :)
I particularly like how you've used decoupling caps as standoffs on the long runs of wire.  :-+


The original plan for the diode arrays was parallel lines of the same wire supported by electrically benign 10M resistors, but that would have been fiddly to make as compact as the veroboard incarnations.   
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 23, 2017, 01:37:12 pm
I've also been working on a prettified "Theory of Operation" document to go along with the actual schematics. Here's a preview of how the graphics are shaping up:


LOL, for a split second there I almost thought you had already started building the thing and were showing us an oscilloscope photo.
 :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 23, 2017, 01:58:26 pm
Okaaaayy..... The score counters are complete. This was the last big chunk of boring logic circuitry to get out of the way and things are getting serious now. For the time being I have unstitched my chroma circuitry and the analogue board currently sporting the beginnings of the Paddle generator, and have put them aside.

I am now tacking these digital boards together in their permanent/ final orientation. The score counters are hardwired in and are operational and the next step is to properly stitch the horizontal board down and tidy up the interconnecting wiring, which will entail replacing all of those higgledy-piggledy flexible silicone-insulated wires with neatly routed solid-core stuff.

Each players score counter is identical and they share a common master reset. I'm currently working on a presentable schematic diagram but for now I've attached below a basic logic block diagram of one of the counters. It's basically a single-digit decade counter with an overflow/carry flip-flop for the half digit. The score counters are manually reset to zero by pressing a push button (which will be mounted on the consoles control panel). The reset button triggers a monostable which ensures a clean reset pulse sufficient to reset all counting flip-flops.  Every time a player misses the ball his/her opponents score counter will be incremented by a clock pulse. When a score counter reaches its maximum displayable value of 19, the "!lock-out" line goes low, inhibiting any further counting. This line will additionally lock out further game play and trigger an alarm in the sound circuit, indicating the winner. Play will be resumed by pressing the manual reset button to once again zero the counters.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310287;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310289;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310291;image)
     
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 23, 2017, 02:02:57 pm
Here's a video of the score counters operating (clock inputs fed in parallel from my function gen. @ 1 Hz):

https://www.youtube.com/watch?v=VAV90AeEhII (https://www.youtube.com/watch?v=VAV90AeEhII)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 23, 2017, 09:39:09 pm
Would it be wise to add 0V markers for each of the traces on the oscillograph ?

For some of the stuff it doesn't really matter; the outputs from Function Generator section for example all end up being AC coupled at their destination, so as long as they're xV/div the offset doesn't really matter.

Where appropriate the overall voltage range (or GND) will be shown either with callout lines next to the image in the document or by showing cursors on the image itself, depending on the situation.

I'm trying to keep the style like old Tektronix service manuals as much as possible. :)

I've also been working on a prettified "Theory of Operation" document to go along with the actual schematics. Here's a preview of how the graphics are shaping up:


LOL, for a split second there I almost thought you had already started building the thing and were showing us an oscilloscope photo.
 :-+

Best compliment I could get, thanks! It is surprisingly hard to simulate the glow and blur of a trace correctly (the same is true for the look of an illuminated graticule too).

I can't wait for you guys to see the finished product. (The board *and* documentation.) :D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 23, 2017, 09:55:54 pm
Would it be wise to add 0V markers for each of the traces on the oscillograph ?

For some of the stuff it doesn't really matter; the outputs from Function Generator section for example all end up being AC coupled at their destination, so as long as they're xV/div the offset doesn't really matter.

Where appropriate the overall voltage range (or GND) will be shown either with callout lines next to the image in the document or by showing cursors on the image itself, depending on the situation.

I'm trying to keep the style like old Tektronix service manuals as much as possible. :)

Yep, I get that and that is no problem for an oscillograph with only one waveform that would naturally have a 0V position on the center graticule. Most Tek ones had only one waveform/graph.  ;)

A little triangle indicating 0V of the same colour as the waveform would be quite adequate.
For a scope novice it takes away any ambiguity.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 24, 2017, 12:11:29 am
I've also been working on a prettified "Theory of Operation" document to go along with the actual schematics. Here's a preview of how the graphics are shaping up:


LOL, for a split second there I almost thought you had already started building the thing and were showing us an oscilloscope photo.
 :-+

Best compliment I could get, thanks! It is surprisingly hard to simulate the glow and blur of a trace correctly (the same is true for the look of an illuminated graticule too).

I can't wait for you guys to see the finished product. (The board *and* documentation.) :D
[/quote]

I thought you had started building too or using some kind of simulator. Excellent "scope" work.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 24, 2017, 12:12:55 am
Here's a video of the score counters operating (clock inputs fed in parallel from my function gen. @ 1 Hz):

https://www.youtube.com/watch?v=VAV90AeEhII (https://www.youtube.com/watch?v=VAV90AeEhII)

That board is art. Should mount it to the wall.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 24, 2017, 12:27:34 am
Okaaaayy..... The score counters are complete. This was the last big chunk of boring logic circuitry to get out of the way and things are getting serious now. For the time being I have unstitched my chroma circuitry and the analogue board currently sporting the beginnings of the Paddle generator, and have put them aside............................................
:scared: That's just too much!  :scared:
I could never imagine wiring sooooooooooooooooooooo many transistors and diodes by hand, or, even, after the rest is added, making a PCB with so many discrete components in my life...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 24, 2017, 01:15:55 pm
I dunno, I think it just requires a little patience. I made some reasonable progress today. I now have all three 300mm X 150mm digital boards permanently stitched together and have tidied up almost all of the interconnecting wiring. In the spare space besides the score counter decoders I had room to spare for the video deskewing DFF (the simpler type comprised of only six NAND gates) and the additional decoding to provide the bottom boundary/border video signal. The screen looks much more complete with the lower boundary, IMO.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310511;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310513;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310515;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 24, 2017, 06:03:19 pm
The screen looks much more complete with the lower boundary, IMO.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310511;image)

Agreed. That does put the finish touch on the playing field. :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 25, 2017, 01:20:03 am
Arrrrg, after seeing that bottom line, plus one of your old analog gravity bouncing ball demos, I'm now thinking shrink the middle fence lower.....x/y use analog joystick bats for each player......tennis......  Just ignore me, continue on....
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 25, 2017, 05:30:55 am
He he.... In addition to the original "Tennis for Two" A good old game that would make for a nice demonstration of analogue computing principles and circuitry would be a variant of one we ran on the BBC micros in high school called Missile Attack or something like that. There were a lot of variants of this game, one which I think came bundled with QBASIC called either Gorillas or Bananas or whatever. Basically the opposing  players have positions on either side of the screen and take turns launching missiles at each other. Firstly, IIRC, you hold your fire button down for a period of time that sets the initial trajectory and then a second time to set the initial velocity, releasing to fire. Then you sit back and watch your projectile take flight and hope that it comes down right on top of your opponents head!

But back to Pong.... For the sound effects this time around I wanna do something a little more sophisticated than the simple "computer sound" beeps of the oscilloscope-display version. I've been playing around in LTspice with simple percussive sound circuits in order to approach something sounding like the thunk of a ball against a wall or bat. Attached is the circuit I think I am going to settle upon, which is an amplifier with a twin-T filter in the negative feedback path, giving a high-Q resonant peak in the pass band. Excitation/triggering is a brief 1mS pulse which will be provided in real life by a monostable. Using the .wave spice directive I've recorded the output to a .wav audio file, which you can listen to:

Bonk.wav (https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310694)

I think that sounds kinda like the bonk of a ball on a bat. I'll have two of these generators, one for the paddle-ball collisions and another lower pitched version for the ball-boundary collisions. Cool, huh?

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310695;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 25, 2017, 05:41:30 am
Yep, sound is half the experience (https://www.brainyquote.com/quotes/quotes/g/georgeluca462198.html).
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 25, 2017, 07:34:10 am
Yep, sound is half the experience (https://www.brainyquote.com/quotes/quotes/g/georgeluca462198.html).


Ha ha (flame suit on!) - For a dull and boring George Lucas film (like Star Wars Episode 0 through 250) that's probably more like 95%!  >:D

Continuing with the documentation, I've revised the Vertical Timing and the Scoreboard Video Signal schematics to correct minor errors and reflect the most current hardware modifications. The former now sports decoding for the net video signal (I was previously assembling this component on the breadboard) and decoding for the lower boundary video signal. The latter now incorporates the video signal deskewing DFF. Some changes have been made to the Horizontal Timing circuit and the buffer of the Master Oscillator circuit (to provide adequate current sinking to drive the DFF clock input) as well, but they're currently a work in progress.   
 
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310716;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310718;image)

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on April 25, 2017, 07:57:50 am
Pong stereo game sound simulation of GK's bonk sound efffect.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 25, 2017, 08:50:55 am
Pong stereo game sound simulation of GK's bonk sound efffect.
Now you've done it.  GK will now release a stereo version of his game....

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 25, 2017, 05:56:09 pm
Yep, sound is half the experience (https://www.brainyquote.com/quotes/quotes/g/georgeluca462198.html).


Ha ha (flame suit on!) - For a dull and boring George Lucas film (like Star Wars Episode 0 through 250) that's probably more like 95%!  >:D

LOL!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 25, 2017, 10:26:20 pm
Pong stereo game sound simulation of GK's bonk sound efffect.

At first I thought that was the start of a song! I was waiting for the beat to drop, but it never did. We just need to add some deep, thumping bass and some 56k modem noises and it could be the next hit dubstep song!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 26, 2017, 09:49:04 am
Pong stereo game sound simulation of GK's bonk sound efffect.
Now you've done it.  GK will now release a stereo version of his game....


Definitely! I hadn't considered the provision for stereo until I listened to that. What I'll do is provide both mono and stereo line-level RCA outputs to accommodate both mono and stereo TVs/monitors. I'll mix it so that the sounds other than the stereo paddle-ball collisions are sent equally to both L & R channels, but 6dB lower in amplitude to compensate for the fact that the paddle-ball boinks are only being reproduced by a single speaker.

Here is the circuit for producing the bell-like alarm that is to sound when a player reaches a maximum (winning) score of 19. If either player 1 or player 2's score counter reaches 19 causing its !lock-out line to go low, NAND gate Q1, ORing these lines, will turn off, enabling the Q2,Q3 astable and gating VR32 (400 Hz referenced from the vertical timing ripple counter) through to Q5.
The non-symmetrical astable produces ~100mS long pulses at a ~1 Hz repetition rate. The pulse output is shaped by D1, R3, R4 and C1 to produce a modulation envelope control voltage with a fast attack and a slow exponential decay. This modulation voltage is buffered by Q4 and applied to the 400 Hz switching stage Q5. The asymmetrical amplitude-modulated envelope produced at the collector of Q1 is ac-coupled and shaped/filtered into a symmetrical waveform by a Wien Bridge RC network with an Fc of 400 Hz.  This alarm/chime will continue to sound until the score counters are manually reset to zero.

I think it sounds a bit like the chime that typically sounds in an elevator before the doors close/open: Bell Sound.wav (https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310944)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=310942;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: tautech on April 26, 2017, 09:59:19 am
 :-DD
Now you've done it. There's no holding Glen back now, he's on a roll.....whatever will he come up with next ?  :scared:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 26, 2017, 10:01:08 am
....whatever will he come up with next ?  :scared:


Dinner!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 26, 2017, 10:23:49 am
What I'll do is provide both mono and stereo line-level RCA outputs to accommodate both mono and stereo TVs/monitors. I'll mix it so that the sounds other than the stereo paddle-ball collisions are sent equally to both L & R channels, but 6dB lower in amplitude to compensate for the fact that the paddle-ball boinks are only being reproduced by a single speaker.
Now when you video demo the final game for Youtube, you'll need to record the audio in stereo...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on April 26, 2017, 06:18:11 pm
:-DD
Now you've done it. There's no holding Glen back now, he's on a roll.....whatever will he come up with next ?  :scared:

Hehe. There are plenty of games to discrete-ize.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on April 26, 2017, 06:27:07 pm
Reminds me a bit of the system beep on the old Macintosh computers.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 27, 2017, 03:19:10 am
Definitely! I hadn't considered the provision for stereo until I listened to that.
I'm thinking along the lines of having a cross-fade, or left-right balance adjustment based on the analog X position of the ball.  This way, where ever the ball strikes, a bat or the top & bottom of the court, or going off the edge, the stereo effect of all your playback sounds will be in the right position whether left, right, center, or slightly off center...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 28, 2017, 08:30:08 am
Definitely! I hadn't considered the provision for stereo until I listened to that.
I'm thinking along the lines of having a cross-fade, or left-right balance adjustment based on the analog X position of the ball.  This way, where ever the ball strikes, a bat or the top & bottom of the court, or going off the edge, the stereo effect of all your playback sounds will be in the right position whether left, right, center, or slightly off center...


I think I might be sold on this idea. The unipolar Ball_X integrator signal controlling the horizontal position of the ball has a range of 0 to 10V. at 0V the ball is off the left of the screen and at 10V the ball is off the right. An op-amp based summing amplifier can be configured as a combined level-shift and inverter to produce the complement of Ball_X; the pair then becoming the control signals for a pair of analogue multipliers governing the signal gain of the left and right audio channels respectively. 

As the control signal, Ball_X, is subsonic and the lowest frequency sound effects tone is a far removed 100 Hz (the buzz when a player misses the ball), a simple two-quadrant multiplier can be used as the control signal feed-through can be high-pass filtered out.

Here is a quick sim to put down my preliminary thoughts. This is a multiplier circuit that shouldn't require any fiddly trimming or component matching. We an only interested in ac signals and are not bothered by DC drift, signal feed-through and even the ultimate "offness" isn't a concern as 20dB cross-fade dynamic range is already ample for a convincing stereo effect.   

The large-amplitude control signal is fed to a long-tail-pair (LTP) with diode loads which both biases and linearises the multiplying LTP transfer function by driving with an inverse hyperbolic tangent.

A positive going signal at the control input of the multiplier progressively attenuates the signal passed through to the output. As the ball is already off the screen (horizontal blanking intervals) when Ball_X or it's complement reaches the 10V limit of range, I've set the transconductance/gm (via emitter degeneration) of the control input LTP to saturate a bit before Ball_X reaches 10V. The 3-pole high-pass filters at the output of each multiplier eliminate the control component.

So this should provide a nicely balanced and effective linear cross-fade from left to right and vice-versa, in accordance to the horizontal position of the ball. 
 
BTW, the ball video generation circuitry is operational and I'm working on finishing the video-based logic-level collision detection and movement circuits. Expect a major update this weekend!

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=311356;image)
 
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=311358;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 28, 2017, 09:48:16 am
Sweeeeeeeet   :-+

Though, stretch the blend so that the volume is a little more equal, closer to full volume on the left and right when the ball is in the center of the display.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on April 28, 2017, 10:48:11 am
Okay guys, finally an update on the Scope Pong board! Due to working with an eye patch over one eye, it's been slow going over the last week. (Pro Tip: Tweezers + Eyeballs don't mix.)

However, tonight I finally finished layout for the last circuit section! Now it's just a matter of placing and moving a couple of the finished sections, finish connecting all the nets together and scattering some additional decoupling over the board and it will be ready for a final review, then a small order of test boards. :D

(http://timb.us/Projects/Scope_Pong/Progress_20170428.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 28, 2017, 02:27:00 pm
That looks very pretty; appears that everything will fit in quite nicely. Hope your eye is OK  :o
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on April 28, 2017, 02:45:14 pm
Just for fun here is the video generation circuitry for the ball. Well it's actually a square, but we're just going to have to pretend that it's a ball, lol. The build is finally getting back into the analogue zone.

In the schematic Ball_Y and Ball_X are analogue inputs, the voltages applied to which determine the position that the ball is drawn on the screen. I will eventually draw a neater schematic than this; this is just my working documentation for now. I haven't finished constructing the ball movement circuits yet, so for the demonstration video embedded below I am just applying a fixed 5V to the Ball_Y input and I am applying a triangle wave from my function generator to the Ball_X input to move the ball on the horizontal axis.

Basically Ball_X and Ball_Y are compared (with comparators) to raster scanning ramp waveforms H_SCAN and V_SCAN respectively and monostables are triggered to produce the horizontal and vertical video components of the ball, which are combined into the composite !BALL_VIDEO signal by NAND gate Q24. There are some minor subtleties involved with the firing of the vertical monostable, concerning synchronization with the horizontal retrace to ensure that at whatever point on the screen the ball is drawn, it is always drawn as a complete square exactly four horizontal lines high.

The horrible strobing effect in the video with the slowly (vertically) drifting dark bar across the entire display is entirely an artifact of my camera.   

https://www.youtube.com/watch?v=x6jQ4nx2cGY (https://www.youtube.com/watch?v=x6jQ4nx2cGY)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=311451;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=311453;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on April 29, 2017, 05:19:34 am
 :scared: That has half the components I thought it should have.
Well done!  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 02, 2017, 11:19:33 am
That looks very pretty; appears that everything will fit in quite nicely. Hope your eye is OK  :o

Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.

(http://timb.us/Projects/Scope_Pong/Progress_20170502.png)

(http://timb.us/Projects/Scope_Pong/Progress_3D_20170502.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on May 02, 2017, 12:59:52 pm

Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.

That looks really neat, it has come along very nicely!
Thanks for putting the effort in (as regards the PCB), for everyone.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on May 02, 2017, 01:36:05 pm
That looks very pretty; appears that everything will fit in quite nicely. Hope your eye is OK  :o

Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.

(http://timb.us/Projects/Scope_Pong/Progress_20170502.png)

(http://timb.us/Projects/Scope_Pong/Progress_3D_20170502.png)
Looks like there's still quite a bit of empty space, or are you leaving that for some graphics?
As mentioned before it would be good to be able to fold over the caps and regulators to allow for a clear plastic cover to sit lower.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 02, 2017, 02:00:11 pm
:scared: That has half the components I thought it should have.
Well done!  :-+


I managed to fit the entirety of the ball video generator, movement and collision detection circuits on a single board; picture attached.

Due to some neglected chores that ended up sapping much of my time on the weekend, I didn't get as much done as I had hoped for; I thought I'd be able post a video of myself playing a match against the machine by now, but my paddle generator circuitry (somewhat revised/improved) still isn't entirely operational.

So below is a video of where I am at now; it is of the machine playing against itself but due to the incomplete paddle generators the paddles are currently invisible! Also for the time being I have (for testing purposes) the relevant collision detection inputs hardwired so that the ball bounces off the right hand paddle at 45 degrees and the left hand paddle at 68 degrees. When the paddle generators are finished the ball will deflect at 45 degrees only if it hits either paddle in the center section, and the 68 degrees is it hits the outer edges. The 68 degree deflection is achieved by multiplying the vertical speed by two.

I made a few other changes. I increased the thickness of the lower border from four lines to 16. I also changed the decoding for the paddle horizontal video components. The paddles were previously ~600nS wide and closer in to the center. The paddles are now 2uS wide and pushed further out to effectively enlarge the playing area. 2uS is the thickness of the vertical segments of the score counter digits.

I increased the thickness of the paddles and the lower border as this permits a faster ball speed. The ball movement circuitry has a lot of similarity to the 'scope display version; there is a Velocity integrator which provides a progressively increasing ball speed and the x and y movements are governed by integrators with flip-flops for each axis setting the direction of travel. However the collision detection between ball, paddles and boundaries and the attendant setting and resetting of the flip-flops this time around is done entirely digitally. Basically the ball video signal (a non-blanked version) is individually NANDed with the scoreboard background video signal, the lower boundary video signal and the video signals of each paddle. If the ball video signal is coincident in time with one of those other video signals, then there is a collision on the screen between the two and the respective NAND gate output will go low.

All of this makes the collision detection in the video version simpler and much more flexible than in the 'scope-display version, but there is a catch. There are over 200 lines to the playing field vertically. Suppose that the velocity is such that it takes 1s for the ball to travel vertically from the very top to the very bottom of this field. In that 1s there will be 50 frames drawn. So the ball will move >200/50 = more than 4 lines vertically between each frame. The lower border was originally only 4 lines high, meaning that at this vertical velocity, the ball, now moving faster than 4 lines per frame, could pass through the lower boundary without the video collision detection noticing!
The horizontal velocity is similarly limited. There are 48uS of each horizontal line visible on the screen to the playing area. Suppose that the ball velocity is such that the ball takes 1s to traverse from leftmost to rightmost. In each frame the ball has therefore traveled 48/50 = 960nS. As my paddles were originally only 600nS wide, they would not permit consistent collision detection at that velocity.

A velocity of only 1s left/rightmost-right/leftmost and 1s upper/lowermost-lower/uppermost is pretty fast, but after watching the screen I decided not quite so fast that a good player wouldn't be able to keep up it and keep a match/duel going too long. I thought the game would be better overall if I could impose a higher upper limit to my velocity integrator, and increasing the paddle widths to 2uS and lower boundary width to 16 lines permitted me to do that.

In the video below I stopped filming at 60 seconds, at which point the velocity integrator had reached about 80% of its maximum speed. As you can see the ball is moving quite fast here - I think it would take a pretty damn good player to keep up!

Anyway, my paddle generators are currently about 60% complete. The next video posted will be of me playing against the machine.   

I filmed this on my employer-provided Iphone this time - the strobing effect isn't nearly as bad as for my cheepo pocket digital camera (there is only a brief periodic "lightning" flash) but there seems to be a mismatch in frame rate between the camera and monitor causing the ball movement at low speed to appear in the resultant video a little bit jerky. It seems to be a bit difficult to make decent video of a video screen. My cheepo digital does 50 Hz so I'm toying with the idea of opening it and probing to see if I can find a reference clock for the frame scan anywhere. Theoretically if available I could knock up a breadboard PLL to substitute my Pong system master oscillator and adjust the phase of the lock such that the previously visible, vertically-drifting strobing bar is shifted to the invisible vertical blanking interval.         

https://www.youtube.com/watch?v=HZU-F2H9WGk (https://www.youtube.com/watch?v=HZU-F2H9WGk)
     
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=312524;image)
 

 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 02, 2017, 02:15:04 pm
Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.



Nice! I'm trying to find the 1uF film capacitors to for the ball-x and ball-y integrators though. These would typically be 5.08mm pitch, 7.5mm W, 6mm D or so. Wondering if you accidentally applied a 100nF ceramic footprint here?
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 02, 2017, 02:21:39 pm
Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.



Nice! I'm trying to find the 1uF film capacitors to for the ball-x and ball-y integrators though. These would typically be 5.08mm pitch, 7.5mm W, 6mm D or so.

Your original hand drawn schematics didn't specify film and being such a large value I just assumed it to be ceramic, which is what's currently implemented. (They're just in front of the relays, which are the black rectangles in the bottom left-center of the 3D image I posted.)

Being an Integrator I suppose film does make sense. I'll find appropriate ones and specify them. It'll take a bit of re-arranging but I can make it work.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 02, 2017, 02:26:58 pm
Your original hand drawn schematics didn't specify film


Whoops.  :-[

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 02, 2017, 02:39:22 pm
That looks very pretty; appears that everything will fit in quite nicely. Hope your eye is OK  :o

Thanks, and yes my eye is doing much better, no permanent damage, just a scratch, thankfully!

Things are now progressing rather quickly with the board. I've managed to get everything to fit on a single 300x300mm board (previously it was 250x400mm) which brings board prices down to roughly $10/ea, which is pretty damn good.

(http://timb.us/Projects/Scope_Pong/Progress_20170502.png)

(http://timb.us/Projects/Scope_Pong/Progress_3D_20170502.png)
Looks like there's still quite a bit of empty space, or are you leaving that for some graphics?
As mentioned before it would be good to be able to fold over the caps and regulators to allow for a clear plastic cover to sit lower.

All those sections still have to be connected to each other, so that will take up a lot of the free space on the bottom side of the board. I also want to make sure the top copper pour can reach everywhere, so I need to leave space between sections for that as well. I also need room towards the sides of the large power supply and audio caps so they can be laid down and zip tied to the board, per your suggestion (I haven't added the holes for that yet). Finally, yes, I need a bit of room for artwork. :)

I most likely could have done the board 200x200mm  if I'd done it as one continuous, tightly packed circuit instead of individual sections connected together. I did it the latter way so that the individual sections (and nets that connect them) could be disconnected, probed and examined by the builder. I feel like this makes it a better for figuring out how the whole thing works, plus I think it looks nicer as a decorative item when not in use.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 02, 2017, 02:51:03 pm
Both boards are looking great!

Tim, glad to hear your eye is OK. With a board that size, can the ground plane sink enough heat for the regulators?

GK, it was interesting reading about the collision detection challenges. Looks like it's running really well.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on May 02, 2017, 07:15:47 pm
Yes, the board looks excellent!  :-+

Will you be providing a quality .pdf before the GND pour for closer inspection?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 03, 2017, 02:31:40 am
Both boards are looking great!

Tim, glad to hear your eye is OK. With a board that size, can the ground plane sink enough heat for the regulators?

Yeah, it should be able to. The heatsinks I've chosen actually have solder pins, so heat will be transferred directly into the top and bottom copper pours, which should greatly increase their effectiveness. I've run some numbers and we should be good for a 15VAC to 18VAC input range with a constant 400mA output on both regulators.

Yes, the board looks excellent!  :-+

Will you be providing a quality .pdf before the GND pour for closer inspection?

Of course! I'll post a 600DPI PDF of the layout for review before ordering the test boards. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 03, 2017, 03:11:40 am
Both boards are looking great!

Tim, glad to hear your eye is OK. With a board that size, can the ground plane sink enough heat for the regulators?

Yeah, it should be able to. The heatsinks I've chosen actually have solder pins, so heat will be transferred directly into the top and bottom copper pours, which should greatly increase their effectiveness. I've run some numbers and we should be good for a 15VAC to 18VAC input range with a constant 400mA output on both regulators.

Great. I was curious because of Mike's comment regarding putting this into a low-profile enclosure. I'm not sure if he envisioned going lower than the heatsinks in the 3D drawing, but plenty of dissipation is good.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 03, 2017, 11:14:34 am
Your original hand drawn schematics didn't specify film


Whoops.  :-[

Okay, fixed!

(http://timb.us/Projects/Scope_Pong/Relay_Cap.png)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 03, 2017, 11:22:07 am
Both boards are looking great!

Tim, glad to hear your eye is OK. With a board that size, can the ground plane sink enough heat for the regulators?

Yeah, it should be able to. The heatsinks I've chosen actually have solder pins, so heat will be transferred directly into the top and bottom copper pours, which should greatly increase their effectiveness. I've run some numbers and we should be good for a 15VAC to 18VAC input range with a constant 400mA output on both regulators.

Great. I was curious because of Mike's comment regarding putting this into a low-profile enclosure. I'm not sure if he envisioned going lower than the heatsinks in the 3D drawing, but plenty of dissipation is good.

Right, I see now that he was asking about doing away with current vertical heatsinks and instead adding horizontal board mount ones, so the regulators could be folded over. I can't really do that as they take up a good deal more space, which I just don't have. If the user's case can't tolerate the height of the heatsinks (which are about 25mm tall)  they could always mount the transistors externally to the case itself and simply run wires between them and the board. That would solve the problem, right?

That would work well with a metal case. (For a plastic or wood case they'd need to mount the transistors to a largish heatsink to dissipate the heat.)

Anyway, here's the provisions to fold the filtering caps over:

(http://timb.us/Projects/Scope_Pong/Cap_Mount.png)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 06, 2017, 12:13:24 pm
Another progress update:

Added short 20AWG jumper wires between the main power bus and each section, instead of direct trace connections. This will allow the ability for the user to disconnect, use a separate external supply or perform current measurements on each individual section, which should be super handy for debugging! It also allows me to easily route other nets between the two pads of the jumper, if needed.

I only plan to use these for power connections to each section. They can be seen in the following renders:

(http://timb.us/Projects/Scope_Pong/Progress_20170506-01.png)
(http://timb.us/Projects/Scope_Pong/Progress_20170506-02.png)


At my current rate of progress I should have the first full layout PDF up for review by the end of the weekend.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on May 06, 2017, 12:21:21 pm
Could have just as well made them 0.1ohm resistors, so placing a volt meter on them will allow current measurements.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 06, 2017, 12:39:25 pm
Could have just as well made them 0.1ohm resistors, so placing a volt meter on them will allow current measurements.

Well, 100mOhm might be too low considering the current draw of a lot of the sections. 500mOhm might be more practical, however there are some complications with that; in some places, I have to daisy chain the power traces between sections, which means you could end up with a significant voltage drop. Using #20 wire works out a lot better, since the resistance is fairly low (tens of mOhms).

Originally I was going to use 0Ohm resistors, but ultimately a piece of wire is a lot less expensive, they have a very low voltage drop and allow a handy place to clip a probe as well!

You can still replace any of the wire jumpers with current shunt resistors if you want, as the footprints I've made will accept standard 1/4W resistors. (For footprints with 3.81mm or 5.08mm pad spacing the resistors could be placed in the vertical orientation, for 7.68mm and larger footprints the resistors could be placed in the normal horizontal orientation).




Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 07, 2017, 01:27:41 pm
Nice to see the board layout approaching fruition. Here is where I am currently at with the Video version. The paddle generators are complete, as is all of the control logic and the game is now completely playable. The photo below shows the video display immediately after power-up. A Power-on-reset timer automatically sets the score counters to zero and the system is put into the default mode; the velocity integrator is discharged and the ball movement integrators are set and held to initial conditions which result in the ball being presented stationary in the middle of the court. The system is now just waiting for the "serve ball" button to be pressed to initiate game play. When a player misses the ball and it travels off either the left or right hand side of the screen the opponents score counter is incremented.

There currently aren't any sound effects however, which really does make it a bit boring! The sound circuitry is up next. And after that all that will be left is the (already proven) video colour encoding circuitry and the power supply.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=313692;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=313694;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on May 07, 2017, 01:41:02 pm
 :popcorn:

 :-+ :-+ :-+ :-+ :-+ :-+ :-+
 :scared: Complete Madness!  :scared:
 :-+ :-+ :-+ :-+ :-+ :-+ :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: dr_dan on May 07, 2017, 02:17:20 pm
Originally I was going to use 0Ohm resistors, but ultimately a piece of wire is a lot less expensive, they have a very low voltage drop and allow a handy place to clip a probe as well!

You can still replace any of the wire jumpers with current shunt resistors if you want, as the footprints I've made will accept standard 1/4W resistors. (For footprints with 3.81mm or 5.08mm pad spacing the resistors could be placed in the vertical orientation, for 7.68mm and larger footprints the resistors could be placed in the normal horizontal orientation).

Is it possible to make them all the same footprint, say the standard horizontally mounted 1/4W resistor footprint?

Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 07, 2017, 02:48:34 pm
Originally I was going to use 0Ohm resistors, but ultimately a piece of wire is a lot less expensive, they have a very low voltage drop and allow a handy place to clip a probe as well!

You can still replace any of the wire jumpers with current shunt resistors if you want, as the footprints I've made will accept standard 1/4W resistors. (For footprints with 3.81mm or 5.08mm pad spacing the resistors could be placed in the vertical orientation, for 7.68mm and larger footprints the resistors could be placed in the normal horizontal orientation).

Is it possible to make them all the same footprint, say the standard horizontally mounted 1/4W resistor footprint?

The standard 1/4W resistor footprint I use everywhere on the board has a 0.75mm/1.5mm hole/pad size and 7.62mm spacing between pads. For the jumper wires I'm using a 1mm/2mm hole/pad size and have 5 different footprints with pad spacing from 3.81mm to 15.24mm. 20AWG wire is about 0.8mm in diameter, so it needs a bigger hole.

Like I said, a normal 1/4W resistor will still fit just fine in the bigger hole if you want to go that route, though you might have to install it vertically any place I used the 3.81mm or 5.08mm pattern, which I've only had to do in a few spots.

If you're worried about having to use a different size drill when making the boards by hand, it shouldn't be that big of a deal, really, as there's only about 20 or so jumpers on the board.

Here's an example image I made showing all 5 sizes of the footprints I've got with 30mil traces running under and between them:

(http://timb.us/Projects/Scope_Pong/Jumpers.png)

I'm nearly done connecting all the sections to the power bus and the 7.62mm footprint is the most common by far, with 5.08mm being used three places and 15.24mm being used one place.

Keep in mind that 0Ohm resistors aren't actually zero ohm. Carbon ones can be close to 1Ohm in some cases! Metal film ones can be 250mOhm or more. I'd highly recommend using a piece of at least 22AWG wire as the jumper to avoid a significant voltage drop on some of the more current hungry sections. (I will be including 20AWG jumpers in the kit. You can actually buy them pre-cut and reeled the same way resistors come, they're only a couple of cent and should save a good deal of time.)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=313692;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=313694;image)

Damn, that's looking hot! Can't wait to turn that into a PCB! :}
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 08, 2017, 02:53:45 pm
Is it possible to make them all the same footprint, say the standard horizontally mounted 1/4W resistor footprint?

Just to clarify what I meant by being able to use a normal resistor in place of the wire jumpers:

(http://timb.us/Projects/Scope_Pong/JMPvsRES.png)

As you can see pad spacing is the same, so using resistors won't be an issue.

In other news, I'm getting closer:

(http://timb.us/Projects/Scope_Pong/Progress_20170508.png)

The external drive that I run my Windows 7 VM on died Saturday, so I spent a lot of time troubleshooting that instead of doing layout. Thankfully the new SSD will be here today (gotta love Amazon Prime).

Routing some of the nets has also taken a bit longer than originally anticipated. Now that I've got all the sections placed, I'm finding ways to optimize things, which means moving and rebuilding small pieces of some sections. It'll be worth it though, as I can do away with quite a few vias.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 08, 2017, 11:29:14 pm
No worries, Tim. Appreciate all the time you've been able to invest into laying out the board.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: dr_dan on May 10, 2017, 07:20:57 pm
Is it possible to make them all the same footprint, say the standard horizontally mounted 1/4W resistor footprint?

Just to clarify what I meant by being able to use a normal resistor in place of the wire jumpers:

(http://timb.us/Projects/Scope_Pong/JMPvsRES.png)

As you can see pad spacing is the same, so using resistors won't be an issue.

Sorry for the slow response - busy at work this week. My reason for asking if they could all be the same footprint was twofold:

It would also reduce the BOM if you were planning to supply pre-formed links as part of the kit.

Not a big deal either way - maybe I'm just a consistency freak... ;)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: james_s on May 10, 2017, 08:06:18 pm
Keep in mind that 0Ohm resistors aren't actually zero ohm. Carbon ones can be close to 1Ohm in some cases! Metal film ones can be 250mOhm or more.

That's interesting, I had always assumed they were just a solid piece of wire with a resistor form molded over. I wonder why they aren't.


Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on May 11, 2017, 09:56:06 am
Keep in mind that 0Ohm resistors aren't actually zero ohm. Carbon ones can be close to 1Ohm in some cases! Metal film ones can be 250mOhm or more.

A quick look on Digikey for 1/4W zero ohm resistors gives 11 results, some carbon film, some metal foil. All have resistance of 20 milliohms or less. :-//
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 11, 2017, 12:18:17 pm
Keep in mind that 0Ohm resistors aren't actually zero ohm. Carbon ones can be close to 1Ohm in some cases! Metal film ones can be 250mOhm or more.

A quick look on Digikey for 1/4W zero ohm resistors gives 11 results, some carbon film, some metal foil. All have resistance of 20 milliohms or less. :-//

I said some. ;)

It generally happens with the cheap grab bags you get from eBay or Ali Express. In a lot of cases they simply remark the lowest normal value they produce (often 500mOhm or 1Ohm) as zero. Other times they're simply QC rejects that have a manufacturing flaw and are resold in these lots.

If you're purchasing direct from Digi-Key you should be alright.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on May 11, 2017, 01:06:03 pm
Keep in mind that 0Ohm resistors aren't actually zero ohm. Carbon ones can be close to 1Ohm in some cases! Metal film ones can be 250mOhm or more.

A quick look on Digikey for 1/4W zero ohm resistors gives 11 results, some carbon film, some metal foil. All have resistance of 20 milliohms or less. :-//

I said some. ;)

It generally happens with the cheap grab bags you get from eBay or Ali Express. In a lot of cases they simply remark the lowest normal value they produce (often 500mOhm or 1Ohm) as zero. Other times they're simply QC rejects that have a manufacturing flaw and are resold in these lots.

If you're purchasing direct from Digi-Key you should be alright.

Good to know.
Sketchy ebay stuff. :scared:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 18, 2017, 11:11:21 am
Just wanted to let you guys know I'm back working on the board again. I ended up having some work come up at the beginning of last week and haven't had any free time the past week. Now that things have calmed down I can finish the board up. :)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: vinicius.jlantunes on May 18, 2017, 11:34:18 am
Wow I hadn't seen this thread yet! This is terrific stuff!  :-+
 :popcorn:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Mukrakiish on May 18, 2017, 01:03:36 pm
Just wanted to let you guys know I'm back working on the board again. I ended up having some work come up at the beginning of last week and haven't had any free time the past week. Now that things have calmed down I can finish the board up. :)
That's great to hear! Can't understand much of who it works but dang is it fun to watch you guys build this piece of artwork.  :popcorn:
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 18, 2017, 06:04:28 pm
Just wanted to let you guys know I'm back working on the board again. I ended up having some work come up at the beginning of last week and haven't had any free time the past week. Now that things have calmed down I can finish the board up. :)

Thanks for the update, Tim. I still get a chuckle from your pretentiously polysyllabic profile prose. An amusingly astute archetype of alliteration it is.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on May 19, 2017, 09:08:44 am
Thanks for the update, Tim. I still get a chuckle from your pretentiously polysyllabic profile prose. An amusingly astute archetype of alliteration it is.

Don't encourage him, he still has a job to do.  ;)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 19, 2017, 05:49:08 pm
Tough crowd. :-DD
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 19, 2017, 10:01:19 pm
Just wanted to let you guys know I'm back working on the board again. I ended up having some work come up at the beginning of last week and haven't had any free time the past week. Now that things have calmed down I can finish the board up. :)

Thanks for the update, Tim. I still get a chuckle from your pretentiously polysyllabic profile prose. An amusingly astute archetype of alliteration it is.

Haha, thanks, glad someone gets it!

I came up with it about 10 years ago, back when blogs were at the peak of their popularity. A friend and I used to have a game where we'd try to find blogs with the most pretentiously verbose tag lines possible; run by people who think big words = smart. So anyway, I came up with that Polysyllabic Prose thing and used it as the heading on my website/blog for years, though I finally had to take it down awhile back, as I started using my site more and more for business.

Now I just use it on forums. At least people can see it here. :D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 21, 2017, 05:51:38 am
I've been occupied with other things the past couple of weeks too, but am still working away at the video version. I'm not going to bother with any more progress videos on YouTube; the next video will be of the completed machine.

My hand-drawn (scribbled) documentation was starting to get a mess and beginning to become a nightmare to prepare neatly by hand. Some of the schematics for various functional circuit blocks (the score counters for instance) take up multiple sheets of graph paper and stitching the pages together and trying to get the initial layout correct is too much of a PITA, so I've reverted to drafting all of the schematics for this project in CAD this time around. And with more than a weeks break I need to get orientated again. I'll hit the soldering iron again once the documentation for the currently completed circuitry is completed.

Attached is what I have completed so far. Full resolution versions currently here and being added:  http://www.glensstuff.com/videopong/ (http://www.glensstuff.com/videopong/)

EDIT: Oops; several errors noticed in the "Paddle video generators" schematic. Fixed.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=317299;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=317301;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=317303;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on May 23, 2017, 05:13:34 am
In what are those schematics drawn in? They have such a nice oldschool look to it. Like something you would find in a old service manual or magazene.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 23, 2017, 12:31:30 pm
Protel 99SE, but I've made my own component libraries.

Just uploaded a bunch more schematics for preview & corrected some errors in the previous ones:

http://www.glensstuff.com/videopong/ (http://www.glensstuff.com/videopong/)


Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 23, 2017, 10:19:53 pm
Protel 99SE, but I've made my own component libraries.

Just uploaded a bunch more schematics for preview & corrected some errors in the previous ones:

http://www.glensstuff.com/videopong/ (http://www.glensstuff.com/videopong/)

Looking very nice! Man, I wish the schematic capture part of DipTrace supported 45 degree wires. It looks so much nicer than the lopsided way I have to do it. :(

So I've spent the last two nights picking up where I left off with Scope Pong; I'll have a progress update soon. We're in the home stretch!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on May 24, 2017, 12:33:40 am
Protel 99SE, but I've made my own component libraries.

Just uploaded a bunch more schematics for preview & corrected some errors in the previous ones:

http://www.glensstuff.com/videopong/ (http://www.glensstuff.com/videopong/)

Wow, excellent! Thanks, Glen.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on May 24, 2017, 01:19:36 pm
Looking very nice! Man, I wish the schematic capture part of DipTrace supported 45 degree wires. It looks so much nicer than the lopsided way I have to do it. :(


Yeah, LTspice doesn't support diagonal wires either, which annoys me. If you try to do X-ed wires it forces you to draw a Nazi swastika. 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on May 24, 2017, 04:26:09 pm
LTspice doesn't support diagonal wires...
Yes it does.
To draw diagonal wires, hold down Ctrl while drawing the wire.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 25, 2017, 12:34:00 am
Looking very nice! Man, I wish the schematic capture part of DipTrace supported 45 degree wires. It looks so much nicer than the lopsided way I have to do it. :(


Yeah, LTspice doesn't support diagonal wires either, which annoys me. If you try to do X-ed wires it forces you to draw a Nazi swastika.

I believe you can hold down OPT (CTRL on the PC) to do diagonal wires in LTspice. :D

Edit: Beaten!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Mukrakiish on May 25, 2017, 01:39:11 pm
Looking very nice! Man, I wish the schematic capture part of DipTrace supported 45 degree wires. It looks so much nicer than the lopsided way I have to do it. :(


Yeah, LTspice doesn't support diagonal wires either, which annoys me. If you try to do X-ed wires it forces you to draw a Nazi swastika.

I believe you can hold down OPT (CTRL on the PC) to do diagonal wires in LTspice. :D

Just went and checked it, sure enough...there's your diagnol lines! That's just like the couple shortcuts I found in Solidworks the other day, totally changed my day-to-day work flow now. You're awesome Tim!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on May 25, 2017, 02:49:48 pm
Looking very nice! Man, I wish the schematic capture part of DipTrace supported 45 degree wires. It looks so much nicer than the lopsided way I have to do it. :(


Yeah, LTspice doesn't support diagonal wires either, which annoys me. If you try to do X-ed wires it forces you to draw a Nazi swastika.

I believe you can hold down OPT (CTRL on the PC) to do diagonal wires in LTspice. :D

Just went and checked it, sure enough...there's your diagnol lines! That's just like the couple shortcuts I found in Solidworks the other day, totally changed my day-to-day work flow now. You're awesome Tim!

:D

I've been using LTspice for years and still occasionally discover little secrets like that; it's especially bad on the Mac since there's no toolbar or real UI to speak of. Everything is shortcut keys or right click menus. It reminds me of a terrible Windows 3.1 program.

Though, once you get the hang of the shortcuts you can draft schematics pretty quickly. I wish I could do schematics as quickly in DipTrace!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: HackedFridgeMagnet on June 17, 2017, 11:18:09 am
Hi Timb,
How is the pcb layout progressing?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: CharlesSpong on June 17, 2017, 03:55:08 pm
This project is really cool, you should consider doing a kick-starter for it.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on June 18, 2017, 10:31:46 am
Yes, .......... Earth to timb, over.

I've been doing shack renovations, so have been a bit remiss on the video version. Getting back to it soon.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on June 20, 2017, 02:26:25 pm
Yes, .......... Earth to timb, over.

I've been doing shack renovations, so have been a bit remiss on the video version. Getting back to it soon.

Yes, I'm getting back onto this soon! I've been going back and forth between two customer projects for the last month, but those jobs are done now and I've got a bit of free time to finish this up. :)

Sorry about the false start last time.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on June 27, 2017, 11:57:35 pm
Hey guys, so I took time over the weekend to do a full review of the schematics and layout, in order to get back up to speed. It was well worth it, as I found several errors (one of them a showstopper). So now I'm proceeding with the final stages of layout (connecting all the blocks together) and hope to have progress by the end of the weekend.
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on July 04, 2017, 02:25:41 am
Small update: I got a bunch of the remaining nets connected over the weekend and fixed all the errors I had found last weekend. Maybe July 4th will be Indepongdence Day? We'll see!

(http://timb.us/Projects/Scope_Pong/Progress_20170702.png)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on July 09, 2017, 01:50:00 pm
OK, that's good to hear  :)

I finally got back to the video version this weekend. After a late night this evening the colour video circuitry is all soldered up. I still have to reroute the interconnecting wires neatly, but it's currently fully operational. I opted for a green scoreboard/boundary, red paddles, a yellow ball and a white court net/divider.

Of the currently assembled panel, the colour video generation circuitry occupies the 150mm X 300mm board on the bottom left. The currently vacant 150mm X 150mm space directly to the right of this board will sport the regulated power supply electronics (+/-5V & +/-15V). Actually there are two independent composite video channels/outputs on the video board. One is the colour channel for colour monitors/televisions and the other is a monochrome output in which the luma component is only ever one of two levels - zero (black) or full amplitude white. I soldered up this additional monochrome channel as the colour video signal rendered in a greyscale when viewed on a monochrome TV doesn't look as good. Red, for example, has a rather low-level luma component (30% of peak white), and the paddles appear quite dark on a B&W display. For the monochrome channel the discrete video components for the paddles, ball, court net, etc, are simply logically ORed together. In the colour channel they are processed by a luma (Y) matrix to satisfy the PAL standard; Y = 0.3R+0.59G+0.11B.
     
The blank PCB currently tacked onto the top right of the assembled panel will sport the sound effects/synth circuitry and the remainder of the games control logic. That's the next part to get soldered.

I must admit it's all beginning to look a little complimicated now.......  :P

The colour channel:
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=330611;image)

The monochrome channel:
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=330613;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=330615;image)

Video board:
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=330617;image)
     
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on July 09, 2017, 01:59:27 pm
I'm not convinced the colour is really worthwhile - don't think it adds much to the overall experience and adds more complexity.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on July 09, 2017, 02:00:41 pm
I'm not convinced the colour is really worthwhile - don't think it adds much to the overall experience and adds more complexity.


Thanks.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on July 10, 2017, 03:52:32 am
I'm not convinced the colour is really worthwhile - don't think it adds much to the overall experience and adds more complexity.

Thanks.

But it's cool. ;)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on July 10, 2017, 03:55:24 am
I must admit it's all beginning to look a little complimicated now.......  :P

Hmm, could be. Just a little complimicated, but still so...organized. :o
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on July 10, 2017, 05:14:02 am
Actually the color generation circuitry does not look all that big. I would guess it mostly leverages signals from corresponding circuits that actually draw the objects, so it simply muxes in a different color tone depending on what is being drawn. PAL format is probably easier here.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on August 03, 2017, 02:57:40 pm
Maybe July 4th will be Indepongdence Day? We'll see!



2018?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Gary350z on October 09, 2017, 02:52:17 pm
What happened to the PCB project in this thread?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on October 10, 2017, 10:15:51 am
For whatever reason I presume timb lost interest. If so, perhaps a suggestion to post the unfinished design files (should someone else feel enthusiastic about finishing the project) wouldn't be out of order. Though actual worthwhile collaborative projects that actually come to fruition are nearly as rare as rocking horse poo on these forums anyway. A general waste of time really. 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on October 10, 2017, 11:06:13 am
For whatever reason I presume timb lost interest. If so, perhaps a suggestion to post the unfinished design files (should someone else feel enthusiastic about finishing the project) wouldn't be out of order. Though actual worthwhile collaborative projects that actually come to fruition are nearly as rare as rocking horse poo on these forums anyway. A general waste of time really.

I wish he did the work in Protel99SE....  I would be glad to finish the project as I have the free time in multitudes.
(Though I only have a digital scope, it still has XY, but not blanking.  I can get one one of my old analog ones back from an old friend I gave it to for temporary play...)

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: FrankBuss on October 10, 2017, 03:11:32 pm
For whatever reason I presume timb lost interest. If so, perhaps a suggestion to post the unfinished design files (should someone else feel enthusiastic about finishing the project) wouldn't be out of order. Though actual worthwhile collaborative projects that actually come to fruition are nearly as rare as rocking horse poo on these forums anyway. A general waste of time really.

timb is still active here, profile says last time seen was yesterday.

BTW, I was thinking of building a version with a microcontroller and a DAC. Would be interesting for something like Maker Faire to show the improvement of technology. Like 60 years ago you needed all these 10 PCBs and now you can do it in one microcontroller with the size of a thumbnail. But might end up as another of my many unfinished ideas and projects ::)
Title: Oscilloscope pong for 1 or 2 players.
Post by: timb on October 10, 2017, 03:37:50 pm
Sorry guys, I didn’t lose interest, work just kept cropping up every time I started back up on it, then I was really sick for nearly two months (which is why I stopped posting here for awhile).

Anyway, I actually started working on the board a over the weekend. It’s literally 90% done, it’s just a matter of cross connecting a few sections together, doing some cleanup and getting you guys to to look at the routing to make sure I haven’t missed anything. After that I’ll send out for a test board and order a set of parts.

Really sorry I didn’t say anything. [emoji20]

How is color pong progressing, GK?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: MK14 on October 10, 2017, 05:07:35 pm
It’s literally 90% done

Great.
90% often means, you just have the other 910% left to do, to finish it off.  :-DD
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on October 10, 2017, 10:01:53 pm
Hey, Tim, glad to hear you're doing OK. Being sick for two months is no fun. Welcome back.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on October 15, 2017, 10:19:13 am
I've been preoccupied with other things. Haven't progressed any further with the electronic assembly. However this weekend I got back to it and started the display enclosure. A 3mm-thick sheet of transparent acrylic will be screwed over the top.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=360900;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BradC on October 15, 2017, 12:58:09 pm
I've been preoccupied with other things. Haven't progressed any further with the electronic assembly. However this weekend I got back to it and started the display enclosure. A 3mm-thick sheet of transparent acrylic will be screwed over the top.

Gonna need a bigger pocket!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on October 16, 2017, 07:37:12 am
That's going to look really snazzy, GK. What's the remaining section of copper for?
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: timb on October 16, 2017, 01:34:22 pm
That's going to look really snazzy, GK. What's the remaining section of copper for?

Cup holders, naturally!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on October 16, 2017, 06:25:18 pm
Ah, of course. Just make some round cutouts in the acrylic top. ;D
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on October 16, 2017, 11:05:16 pm
Sound effects/synth and the remaining control logic. Might make a start this weekend, but the project is second in priority to finishing off my duck pen.

Quack!

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=361274;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 07, 2018, 04:42:25 am
Finally getting stuck into this project again. I have the sound synth circuitry soldered up to the extent that I can play against the machine with the percussive boink ball-bat and ball-boundary sounds. I'm currently waiting on the final batch of parts to arrive in the mail, so I've made some progress on the documentation. 

Here is the complete diagram of the colour composite video generation circuitry. Full res. PDF here: http://www.glensstuff.com/videopong/composite%20video%20generation.pdf (http://www.glensstuff.com/videopong/composite%20video%20generation.pdf)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=384846;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: THDplusN_bad on January 10, 2018, 10:56:31 am
Hello Glen,

a word of thanks for sharing all this with us and for the inspiration! Have a great New Year 2018.

Cheers,

THD+N_bad

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 17, 2018, 05:43:26 am
Hey thanks.....no worries..... two weeks into the new year gone already.........It feels like I was only just organizing my annual leave last week..

I'm keen to finally get this project off the bench and hanging on the wall. I have the power supply circuitry built and operational now.....

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387204;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387206;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387208;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on January 17, 2018, 07:04:50 am
Nice!  A compact all discrete transistor portable video pong game console.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 17, 2018, 09:02:06 am
That's the plan  :)

I now have the whole thing operational on its own internal power supply circuitry. Also finally tidied up all of the wiring to the composite colour video signal generator section. Essentially all that I have to build now is the small amount of remaining control logic and the sound effects circuitry which pans the the audio from left to right and vise-versa depending on the horizontal position of the ball. This will all nicely fit into the remaining area of free copper at the end opposite of the big PSU regulator heatsink.   

The five RCA sockets in the control panel are to be:

1) Composite video monochrome
2) Audio monaural

3) Composite video colour 
4) Audio Left
5) Audio Right

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387231;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387233;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=387235;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Ranayna on January 18, 2018, 08:41:12 am
That is a pice of art.  :clap:

And that it actually does something cool makes it even better.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 18, 2018, 11:26:44 am
OK guys, here is a video of this evenings effort. In addition to the previously constructed percussive sound synth circuitry, I now have the stereo panning circuitry operational as well.

I'm feeling lazy so I'll just cut 'n' paste the explanatory text that I posted with the Youtube video:

Quote
This project is almost finished now. This video demonstrates the stereo sound panning circuitry, which amplitude-steers the synthesized percussive "boink" sounds (that the ball makes when it hits a paddle or the boundaries) between the left and right audio channels depending on the horizontal position of the ball.

There are no actual sounds operating or recorded in this video though. What I have done, simply for clear demonstration purposes, is to disconnect the sound effects generators and feed a continuous audio-frequency sine wave from a function generator into the stereo panning circuit.

The CH1 (yellow) and CH2 (blue) traces on the oscilloscope screen are the left and right audio channel outputs respectively.

As you can see, when the ball is in the center of the screen, both channel outputs are at equal amplitude, centering the stereo image, but when the ball is rightmost the audio is panned entirely to the right audio channel and vise versa.

So long as you aren't sitting too far away from the screen, the stereo effect is quite convincing, even on a relatively small stereo TV not having by virtue of its size much separation between the left hand and right hand speakers. 

https://www.youtube.com/watch?v=aK8zhy-yDac&pbjreload=10 (https://www.youtube.com/watch?v=aK8zhy-yDac&pbjreload=10) 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on January 19, 2018, 05:55:58 am
Despite having watched this develop, it's still hard to believe you made all that, GK. Amazing and cool.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: cowasaki on January 20, 2018, 12:34:54 am
Very impressive.  It would drive me nuts though!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 20, 2018, 05:24:41 am
Ha Ha. I wish I was payed to do this 7.5 hrs per day as my day job. Then I'd be able to build something really ambitious   :)

I now have all of the sound circuitry built and operational. The realistic synthesized percussive ball-thwack sounds in addition to the stereo effect really puts this version, audio wise, a level above the original oscilloscope Pong with its simple "computer" beeps.

I've just finished drafting the Audio Circuits schematic diagram - preview attached.

It's getting really close now. All that is left to do (besides the rest of the documentation) is to finish off and wire in the remaining the control logic: one player (vs machine) or two player, paddle size selection (large or small), etc.

A tally of the semiconductor count so far (from the currently completed/drafted schematics) is as follows:
             
Transistors (bipolar) : 431
Transistors (FET) : 6
Diodes : 828


EDIT: Oops - just noticed a missing 10k collector pull-up resistor on the "Missed-ball buzzer gate".
(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388061;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 21, 2018, 12:10:18 pm
Now when you video demo the final game for Youtube, you'll need to record the audio in stereo...


I picked up a "BD-HDD Combo" recorder unit with composite video and stereo audio inputs this evening which will allow me to do just that.   :)

An earlier test on my living room stereo flat screen:

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388410;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 21, 2018, 12:21:12 pm
OK, here is where I am with the construction as of this evening. the controls are all wired and I can now select either small or large bat sizes. Now that the remaining paddle control circuitry has been built, in single player mode when the machine takes control of the right hand paddle, the paddle-to-ball offset is now corrected so that the ball hits the center of the paddle (those who watched my previously posted video would have noticed that the ball previously only hit the very top of the machine-controlled paddle.

The bolts that hold the transformers and the earth lug to the mains-stuff sub-chassis do not go through the wooden (12mm-thick ply) base. The wooden base was recessed for the bolt heads underneath the steel plate. This means that if the wooden base ever caught on fire the transformers and the critical earth bond would not work loose from the metal plate. It's all safe.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388412;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388414;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388416;image)

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 21, 2018, 12:25:16 pm
.... Cont.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388418;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388420;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=388422;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on January 22, 2018, 05:06:18 am
Are you going to hang the finished "console" on the wall? It'd be cool right above whatever TV becomes the official Pong display device.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on January 22, 2018, 12:39:41 pm
Yeah, I have a computing corner in the shack with an empty bit of wall above the monitors.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on January 23, 2018, 01:36:37 am
Sweet!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: German_EE on February 02, 2018, 06:00:04 pm
Totally cool!  :-+  :-+  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 03, 2018, 01:55:38 pm
Thanks  :)

Aside from a tackle box-style carry handle and the clear acrylic sheet cover, which I haven't ordered yet, the construction is 100% complete. Just working on the documentation and the final presentation now.

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=391966;image)

(https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/?action=dlattach;attach=391968;image)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on February 04, 2018, 02:00:21 am
 :clap:  :clap:  :clap:  :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: fireworks on February 04, 2018, 09:42:58 am
  YouTube video, please ? 😀
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 04, 2018, 12:54:42 pm
Still working on the video. I have this Samsung "BD-HDD Combo" Blue ray/DVD/Hard disk personal video recorder here at the moment for other reasons, and assumed that I'd be able to use this to record to the internal HDD the composite video output from my Pong machine directly, but as it turns out the composite video/audio jacks on the rear of this thing are outputs only. The stupid thing can only record from the internal digital TV tuner.  I have an old TEAC DTV tuner set-top box that will record MPEG video to a USB stick, but as per the Samsung box, from the DTV tuner only.

I would have thought that legacy support for the displaced analogue video would be reasonably well catered for in the modern digital "personal video recorder" market (for instance people needing/wanting to back-up their old VHS tapes/home videos) but all I can find so far, searching for personal video recorders with legacy composite video input(s) are references to no-name-brand PC adaptors which (from reading the available reviews) generally have crappy or sub-standard image quality and are plagued with flaky software.

In any case I'd be in the market for a modern DTV HDD PVR and it would be nice find one with legacy support in the form of a composite video input with companion stereo audio inputs from which it can actually record.

Does anyone reading have any experience here or can suggest a brand or model number that I can pick up at Harvey Norman or something? If not the quickest fix to get my Pong video recorded might be to drop into Jaycar to pick up one of these:   https://www.jaycar.com.au/usb-2-0-dvd-maker/p/XC4867 (https://www.jaycar.com.au/usb-2-0-dvd-maker/p/XC4867)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 04, 2018, 01:17:03 pm
Hmm, just checked to see if my Samsung TV, which has composite video inputs, has the ability to record to a USB stick or an external HDD. Ooh, there is a "record" button on the remote, which I've never payed attention to before. Woo Hoo! It does indeed! To both a USB stick and my external HDD. Looks like I don't need to buy a PVR to record DTV then, as I've effectively already got one in my TV. So then I selected the "AV" (composite video) input channel and pressed the record button - "function not available"  :palm: The F%$#ing TV has inputs for and can display a composite video signal, but it can't f%$^ing record it.
     
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: John Heath on February 05, 2018, 05:35:27 am

I just caught the tail end of this thread. To GK my hat goes off to you. 1 percent of that build would drive me nuts. Well done. To keep ping pong score a Z80 CPU made of discrete  transistors ,, forget what I said as there is a chance you would do it.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 05, 2018, 05:44:47 am
First, all transistor vector based oscilloscope pong.
Second, all transistor based video pong.

Next?  Like I said in an earlier post, time for all transistor asteroids game, though this one will need at least something like 9 moving sprites, with wrap-around the borders instead of bounce, to look good unlike the current 1 ball + 2 paddles.  To simplify things, keep the spaceship in the center, just make it rotateable with firing and maybe a few seconds of shield with slow recharge, + maybe as much as 3 simultaneous bullets.  I guess if you want it simple, 1 bullet, which may be instantly reentered if shot again before going off the edge of the screen.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on February 05, 2018, 06:19:20 am
Sweet project :clap:

Asteroids would be pretty damn cool, but im pretty sure that would need to be mostly digital and that eats up transistors very quickly to the point of it being closer to a single purpose computer rather than analog. Perhaps a more simplified version of it could be done all analog where the rocks are circles and they don't split and collide with each other. I think most of the movement could be done with a pile of integrators and sample and holds. Collision detection could get quite involved tho.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 05, 2018, 06:31:00 am
Sweet project :clap:

Asteroids would be pretty damn cool, but im pretty sure that would need to be mostly digital and that eats up transistors very quickly to the point of it being closer to a single purpose computer rather than analog. Perhaps a more simplified version of it could be done all analog where the rocks are circles and they don't split and collide with each other. I think most of the movement could be done with a pile of integrators and sample and holds. Collision detection could get quite involved tho.
Your lacking imagination here.  3 small asteroids on-top of each other adjacently making 1 large one = 3 sprites with identical trajectories like having 3 pong balls in the current game.  The first fire collision breaks the 3 up by altering the trajectories of 1 or 2 of the 3 giving you the smaller object.  If you look at the ball's programmable x/y charge oscillator in the schematic, this would be multiplied by 3 for this task.  Multiply again by 3 to start with 3 large asteroids.  Window comparators to activate the pixels located at the proper coordinates during the output scan and use as collision detectors for the gun fire.  Everything which has already been done, though, GK will need to get a little more clever with the layout for space and change the bounce on some of the objects to mirrors to make the asteroids appear to fly off 1 side of the screen and appear on the other side.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 05, 2018, 09:58:34 am
Maybe something like this is what you need. Note: I'm not recommending it, only suggesting. I've never used one.

https://www.ebay.com.au/itm/OZ-Capture-Card-Video-USB-2-0-VHS-to-DVD-Adapter-Converter-EasyCap-PC-PS3-XBOX/111044087624?epid=1191490822&hash=item19dabe4f48:g:ofgAAOSwdAxZbQYl (https://www.ebay.com.au/itm/OZ-Capture-Card-Video-USB-2-0-VHS-to-DVD-Adapter-Converter-EasyCap-PC-PS3-XBOX/111044087624?epid=1191490822&hash=item19dabe4f48:g:ofgAAOSwdAxZbQYl)

There appear to be cheaper options direct from China. But this one claims to be shipped from Sydney.


Yeah, that one of the USB dongle-like devices I mentioned in my other post. The problem is most of these are rubbish. I bought the one I linked to above from Jaycar this

afternoon. Follow the saga here:  https://www.eevblog.com/forum/chat/kworld-dvd-maker-2-from-f (https://www.eevblog.com/forum/chat/kworld-dvd-maker-2-from-f)$ing-jaycar/

HDD PVR's with record-able "AV" inputs now seem to be quite rare. The only model which I can find which is not listed as a discontinued product and is readily available off-the-shelf over here is Strong's SRT7014, but it's $400: 

https://strongaustralia.wordpress.com/2014/07/11/just-arrived-srt-7014-twin-tuner-digital-video-recorder-with-av-input-rs-232/ (https://strongaustralia.wordpress.com/2014/07/11/just-arrived-srt-7014-twin-tuner-digital-video-recorder-with-av-input-rs-232/)

Looks like a nice unit overall though.


Sorry I can't reply to the other posts right now in a meaningful way as my "DVD Maker 2" woes have already eaten away more hours than I have to spare this evening.
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on February 05, 2018, 10:56:41 am
I wouldn't be so worried about capturing the direct video from it.

If you fiddle with a camera for long enough you can get it to capture a CRT screen just fine. As long as the camera you have allows enough in the way of manual settings. Automatic settings tend to really hate CRTs.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 06, 2018, 07:33:59 am
Yeah, my work Iphone 6s in 4k mode captures the screen fine without major strobing, but I would like to include a directly-recorded segment in my final video to demonstrate the panning stereo sound.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: NiHaoMike on February 06, 2018, 08:12:59 am
I vote for a composite/Svideo to HDMI converter plus a LKV373A HDMI streamer box. About $10-20 for a cheap but decent converter and $33 for the streamer. MsMadLemon uses a similar setup to capture retro video games.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 06, 2018, 08:18:26 am
2 additional possible options with equipment you may have on hand.

You can always capture the audio on you PC's line in, then use that audio to replace the audio of the iphone video.

If you have a laptop with a good enough built in webcam, and a stereo line input next to the headphone jack, you can record from that camera & use the line in instead of the microphone audio when recording the video.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Kean on February 06, 2018, 08:58:04 am
Maybe GK can use a composite/Svideo to HDMI converter with his Samsung TV recording feature
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 06, 2018, 09:08:18 am
That was my immediate idea, just after reading NiHaoMike's post. Jaycar (LOL), which I drive past twice every weekday sell a composite video to HDMI converter. However having just checked my TV, annoyingly, as per the composite "AV" input, it won't record from the HDMI inputs either. It's internal "PVR" function operates with the DTV tuner only. There can't be a serious hardware reason for this. Why the sets firmware and recording functionality/usefulness should be purposefully crippled in this way I can only guess. 
 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: mikeselectricstuff on February 06, 2018, 10:32:20 am
That was my immediate idea, just after reading NiHaoMike's post. Jaycar (LOL), which I drive past twice every weekday sell a composite video to HDMI converter. However having just checked my TV, annoyingly, as per the composite "AV" input, it won't record from the HDMI inputs either. It's internal "PVR" function operates with the DTV tuner only. There can't be a serious hardware reason for this. Why the sets firmware and recording functionality/usefulness should be purposefully crippled in this way I can only guess.
There is a good hardware reason - for DTV it can simply copy the already-compressed DTV stream to disk.
For HDMI or composite it would need to compress it in realtime.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 06, 2018, 11:27:54 am
That was my immediate idea, just after reading NiHaoMike's post. Jaycar (LOL), which I drive past twice every weekday sell a composite video to HDMI converter. However having just checked my TV, annoyingly, as per the composite "AV" input, it won't record from the HDMI inputs either. It's internal "PVR" function operates with the DTV tuner only. There can't be a serious hardware reason for this. Why the sets firmware and recording functionality/usefulness should be purposefully crippled in this way I can only guess.
There is a good hardware reason - for DTV it can simply copy the already-compressed DTV stream to disk.
For HDMI or composite it would need to compress it in realtime.


Which is just a codec/ASIC/chipset; pretty trivial these days AFAIK, but I guess my TV probably doesn't have one for reasons of economy, though it is a few years old already. It does have a lot of useless functionality that I'd happily trade for the ability to record from the external video inputs though.
   
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Berni on February 06, 2018, 11:52:15 am
Video encoding a lot different than decoding so it needs extra engineering work to make it happen too. Also it usually takes more processing power to encode video than it takes to decode it.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 06, 2018, 04:16:08 pm
I truly wish I had a cheap capture option for you, but the truth is all those sub 50$ USB2.0 devices use the same garbage IC and if you read their customer reviews on Amazon, you will always find somewhere when someone connect these devices to an old gaming console which ran in 240p/262p progressive instead of 480i/525i, they freeze the image regularly and the audio is massively out of sync.

Unless you go for a name-brand device hoping that they use a completely different chipset, you might end up with the same problems.

If you can record stereo audio into your PC's Line In to your PC like my earlier suggestion, I am willing to swap the audio on your video file from your iPhone if you are unable to do this.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: hornpipe2 on February 07, 2018, 04:57:20 pm
2 additional possible options with equipment you may have on hand.

You can always capture the audio on you PC's line in, then use that audio to replace the audio of the iphone video.

If you have a laptop with a good enough built in webcam, and a stereo line input next to the headphone jack, you can record from that camera & use the line in instead of the microphone audio when recording the video.

Do this.  I tried it before, and it works well.  Here are the steps:

* Plug Pong video-out into TV, audio-out into PC mic-in (or line-in).
* Point camera at TV.  Put it on a tripod so it doesn't move.  Stand far back and optical-zoom in to fill the screen, and minimize pincushion distortion.  Turn off auto-exposure and mess with the manual settings for aperture / ISO until it looks good.
* Start Audacity on PC.  Adjust input volume so the peak level is nearly at, but not touching, the top/bottom of the graph.
* Hit Record on Camera and PC.
* Fire up Pong and play some rounds.
* Later, dump the camera data to the PC.
* Open the video in an editor, import the audio, synchronize the two, trim, export, and post!
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: AF6LJ on February 07, 2018, 06:33:05 pm
Wow just WOW!
That is too cool...
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 07, 2018, 11:35:50 pm
If you can record stereo audio into your PC's Line In to your PC like my earlier suggestion, I am willing to swap the audio on your video file from your iPhone if you are unable to do this.


OK, I'll do that this weekend. I'm not sure that my video editing software supports the separate insertion of audio. If not I'll take you up on that offer and upload the audio and video files to a folder on my web domain. This will only be a 30s or so clip that I will incorporate into a longer video.

I'm mostly done with the documentation and am keen to get this project finished off and posted to a page on my site so that I can move on to the next project  ;)

Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 08, 2018, 12:07:03 am
If you can record stereo audio into your PC's Line In to your PC like my earlier suggestion, I am willing to swap the audio on your video file from your iPhone if you are unable to do this.


OK, I'll do that this weekend. I'm not sure that my video editing software supports the separate insertion of audio. If not I'll take you up on that offer and upload the audio and video files to a folder on my web domain. This will only be a 30s or so clip that I will incorporate into a longer video.

I'm mostly done with the documentation and am keen to get this project finished off and posted to a page on my site so that I can move on to the next project  ;)
Glad to do it freely...
(Note I use an old public domain VirtualDub video editor which allows alternate audio tracks, audio/video alignment scope & direct stream save option retaining the original compression without re-processing.)
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: GK on February 09, 2018, 09:24:35 am
OK, cool. I'm currently on a mission to complete all projects I've already started, which is why this video Pong has been dragging on a bit. My next major project for the bench will be finishing of my PET2001 computer clone, however that doesn't mean that I can't fit a few little projects in between.

I don't know what timb's plans are for his PCB layout of the original discrete Oscilloscope Pong, but one thing I'd like to do next, Pong wise, is to as directly as possible replicate both my Oscilloscope Pong and the Video pong in integrated circuit logic/op-amps/analogue-switches/comparators. Each will preferably be a single board PCB design for through-hole parts.

If there is any significant enthusiasm for this I'll get onto it sooner rather than later. I'll start a new thread for the discrete IC-logic/IC-analogue (uC/uP-free) Asteroids.



 
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: bitseeker on February 09, 2018, 09:53:31 pm
Yes, an IC-based version is probably appealing to more DIYers. :-+
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: BrianHG on February 09, 2018, 11:07:27 pm
Hello GK,

     One note when sampling your audio for your Video Pong game.  Use 48Khz, not 44.1KHz.  This is not a quality issue, it's just that the default audio sample rate for most video encodes is by default 48KHz and some video editors mess up the mixing of 44.1KHz sound tracks occasionally dropping frames to retain AV sync.

Regards,
Brian.
Title: Re: Oscilloscope pong for 1 or 2 players.
Post by: Auciele on February 12, 2018, 03:58:49 pm
Hello,

that's quite an impressive project you did there. If i may be a bit selfish: would you agree to take a top view HD picture of the "board" because i definively want this as my new computer wallpaper?

Thanks