EEVblog #787 - Mailbag

[EEVblog]

More Mailbag
Forum:

SPOILERS:
Zhiyun Z1-Evolution 3-axis GoPro IMU based handheld image stabiliser gimbal:
http://www.zhiyun-tech.com/index.php?m=content&c=index&a=lists&catid=54
http://www.skytechinnovation.com.au/

Nagle Industries Glow-Tie, RGB LED Bow-Tie:
http://www.nagleindustries.com/
https://www.kickstarter.com/projects/nagle-industries/795935220

https://www.kickstarter.com/projects/gooligumelec/wombat-a-prototyping-platform-for-raspberry-pi/description

Raspberry Pi Wombat Prototyping board
http://www.gooligum.com.au/raspberry-pi/wombat-proto
https://www.kickstarter.com/projects/gooligumelec/wombat-a-prototyping-platform-for-raspberry-pi/description

Casio FX-991EX Calculator with engineering notation display.
http://edu.casio.com/products/cwiz/fx991ex/

Hobby Creek Third Hand Tool:
http://www.hobbycreek.com/shop/

KVM switch teardown

[janoc]

Dave, the third hand kit is originally a SparkFun product:
https://www.sparkfun.com/products/11784

They have licensed (?) the idea from someone who has described this on Instructables (the link is on the SparkFun website). The "arms" are actually lubricant hoses for machine tools (like a lathe or a mill). The large holes in the base allow you to screw in additional ones or one with a different attachment (magnifier, fan, etc). There is actually a screw under the orange tip, just "break off" the tip (it takes quite a bit of force to spring out the spherical joint, don't hesitate to unleash brute force on it!) and then you can replace the crocodile clip with something else. SparkFun has a video on their website on how to assemble these hoses - it is quite difficult!

I have the SparkFun one and it certainly doesn't tip over like the one you have - the base seems to be larger a bit. You can solder on it if you hold the board using 3 of the clips, then it is pretty rigid even though clunky. I cannot imagine using it to hold probes, though, because the hoses are very "springy" and it is difficult to get them positioned accurately.

[ornea]

FYI

Not sure if it should be but this Mailbag video is not on the main page at http://www.eevblog.com/ ... update, it is now.

Not up with exactly what open source hardware is about but I was not expecting to see patent pending on an Open Source Device 

[firewalker]

I have seen machinist using soap water hoses as third hand for decades. Mainly for mounting magnifying lenses and lights.

Alexander.

[hikariuk]

If you'd watched the "I Dream Of Wires" documentary you had on one of your earlier mailbags you'd know Muff Wiggler :p

I am happy to say I get the Shermer Illinois reference...although this shows my age.  I think I may need to re-watch the relevant film now (fortunately I have it on BluRay).

[Harrkev]

Sorry Dave, but I can't take a man seriously if he doesn't like peanut butter and chocolate together.  It makes me question all of his other decisions.

[Fungus]

Those calculators are way cheap, $26 on eBay with free shipping. I was expecting more than that. I might have to get one, my current calculator sucks. OTOH you're right, VPAM sucks for basic, quick calculations.

PS: Calculator review and you didn't calculate '69!' ??


PPS: Aluminium for a counterweight on a stabilizing arm? Fail. I'd glue some nuts and bolts to it.

[steve30]

I noticed the bow tie said 'Pending Patent Pending'. Presumably that might be a joke to mean that it is not patent pending.

The calculator looks good, but why does it use that Chinese style serif font? Looks weird.

[max666]

That ServSwitch KVM switch teardown was much more interesting than I expected. That's to no small part due to your excellent teardown skills, Dave. 

I always have my Ti-92 Plus in arms reach, and the Infix Notation certainly has it's pros and cons. I prefer it for more complex calculations though.

[adrian]

Aw Dave, you didn't see the Game of Life generations going on the Glow-Tie? It is the 4th mode shown in the video after the VU meter one. Got really excited when I saw the Game of Life going!

[apis]

I'm thinking about buying the fx991ex now, because I have been wanting one that does complex numbers in a convenient way. Made me take a look at my old (>15yr) fx-82LB, it's rated as 0.4 mW and still use the original casio branded alkalines!

Those prototyping boards look nice but I wonder how much protection/regulation there is, I've had cheap ones before (ie not the wombat one) and it's easy to mistakenly short something on the board since it's unprotected and can damage some of the components. It might have been better to put some acrylic over the board for protection?

[Razor512]

$500 is way too much for that gimbal ($500 is DSLR compatible gimbal territory), especially since it stabilizes similarly to those $50 gimbals for quad copters, though their build quality is lower, with exposed PCBs, and thinner aluminum construction material, at least based on rough comparisons from what I can find on youtube of people testing the cheap ebay gimbals.

Though I did not see anything with vigorous movements like in the EEVblog video.

[Porto]

SJ4000... a rip-off of a rip-off? 

[cteffects]

Very sexy shirtless flash-frame at around 9:20. 

[Neganur]

Those calculators are way cheap, $26 on eBay with free shipping.

That's some 28 EUR for me after adding VAT
Indian Amazon sells them for ~15 EUR/17 USD incl shipping to Mumbai.
Local shops in Helsinki: 35-38 EUR. Crazy.

[apis]

That's some 28 EUR for me after adding VAT
Indian Amazon sells them for ~15 EUR/17 USD incl shipping to Mumbai.
Local shops in Helsinki: 35-38 EUR. Crazy.

I see a lot of the cheap products you can buy for 1$ on ebay (including airmail from China) being sold in local shops for 10-20$. I'm guessing the Chinese sellers have a nice profit margin as well and most of that price is the shipping cost...

Makes you wonder about what it actually cost to produce things and why the market prices are so different from production cost. Of course, market prices are not supposed to be production cost, rather it reflects what people are willing to pay. But in a free market economy they should be relatively similar? My theory is that there isn't nearly enough competition in most markets for it to be considered a working free market. For example, there is only one brand of razors you can buy around here. In any case, something isn't right.

[max666]

Aw Dave, you didn't see the Game of Life generations going on the Glow-Tie? It is the 4th mode shown in the video after the VU meter one. Got really excited when I saw the Game of Life going!

I didn't notice the Game of Life, but Game of Life for the win!
Nice profile picture by the way 

[acourtois]

I guess I am Dave approved.

[pickle9000]

Brushless gimbal

Here's an example of the kinds of shot's you can achieve. Lots of good shots on this channel.



- Keep in mind that rapid changes in altitude will show as shake. An extended arm helps.
- Framing is tricky, remote monitor is very helpful.
- Use "follow mode" for most shots.

[EEVblog]

Aw Dave, you didn't see the Game of Life generations going on the Glow-Tie? It is the 4th mode shown in the video after the VU meter one. Got really excited when I saw the Game of Life going!

Ah, missed that!

[EEVblog]

I guess I am Dave approved.

Not with that TI you ain't 

[Christe4nM]

You just got me to order a FX 991ex on eBay. It got my attention on looks then hooked me by being able to do binary and hexadecimal calculations and conversions. Smaller than my good old TI-84 too.

[redshift]

Very sexy shirtless flash-frame at around 9:20. 

I noticed that too... Some kind of bizarre subliminal message?

Maybe one leftover frame from a scene that he decided to take out?

Any explanation Dave? 

[pickle9000]

Very sexy shirtless flash-frame at around 9:20. 

I noticed that too... Some kind of bizarre subliminal message?

Maybe one leftover frame from a scene that he decided to take out?

Any explanation Dave? 

ha ha.... awesome and juvenile

[steve30]

Ah ha!. I thought I saw his shirtless for a fraction of a second, but didn't bother to go back and look  .

[teerosheyal]

In 42:08

...So Dave from gooligum electronics, Yes because everybody in Australia is called Dave...

And i thought that everybody in Australia is called Bruce...

[maartenva]

If you want to translate the chinese manual, you can you use the google translate app on an android Phone.
You can take a picture and it translate it for you to any language.

https://play.google.com/store/apps/details?id=com.google.android.apps.translate&hl=en


Greetings from Belgium
Maarten

[Fungus]

You just got me to order a FX 991ex on eBay. It got my attention on looks then hooked me by being able to do binary and hexadecimal calculations and conversions.

Can't you do those in your head? I dunno, youngsters today...

I noticed there's an FX 991ex emulator you can download on the CASIO web site. I though I'd have a play around with it before deciding if I want one but I failed to get past their incredible software licensing system.

I don't seem to have a "claim code". Do you have to actually buy a calculator to get one of those and be able to install the 90-day trial of the emulator?

[ornea]

Very sexy shirtless flash-frame at around 9:20. 

I noticed that too... Some kind of bizarre subliminal message?

Maybe one leftover frame from a scene that he decided to take out?

Any explanation Dave? 

ha ha.... awesome and juvenile

Impressed 1/25 sec ... I didnt even notice the shirt change

[ornea]

Calculator came in the mail. Belongs in the mailbag.

[Christe4nM]

You just got me to order a FX 991ex on eBay. It got my attention on looks then hooked me by being able to do binary and hexadecimal calculations and conversions.

Can't you do those in your head? I dunno, youngsters today...

I noticed there's an FX 991ex emulator you can download on the CASIO web site. I though I'd have a play around with it before deciding if I want one but I failed to get past their incredible software licensing system.

I don't seem to have a "claim code". Do you have to actually buy a calculator to get one of those and be able to install the 90-day trial of the emulator?

If you mean binary to hex conversions and back, those you can do in your head indeed: peanuts. But I'm not that good when converting say 24 bits binary to decimal

Currently I use the windows calculator for that, but I strongly dislike the lack of a proper physical calculator that you can poke your fingers at.

...and I needed the excuse to buy that nice looking Casio

[Eliminateur]

150 bucks for the bowtie?, hell no, funny novelty but not at that price

[Fungus]

I noticed there's an FX 991ex emulator you can download on the CASIO web site. I though I'd have a play around with it before deciding if I want one but I failed to get past their incredible software licensing system.

I figured it out. The trick is to ignore all the on-screen instructions and press 'cancel' when it asks you for the license code. 

If you mean binary to hex conversions and back, those you can do in your head indeed: peanuts. But I'm not that good when converting say 24 bits binary to decimal Currently I use the windows calculator for that.

To be fair, that would be one of the reasons I'd buy one, too.

But...I played with the emulator and seems like they managed to make it annoying. Not at all easy to use like Windows calculator.

To convert a number you select your mode, type in a number, press '=', then press a number-base button to convert it. 

Yes, it's only one extra button but why can't I just press the number-base button without typing '=' first, like on Windows calculator? So near, yet so far away... I guess my venerable HP 20S lives another day.

PS: Yes, the calculator accepts "sin(45" without a closing bracket.

[SeanB]

I still use the Fx 602p I had in school, and it is IIRC on the third set of CR2032 cells since it was new. Used to have the companion printer, but that wore out, plus the pens it used were incredibly expensive as a student. Played nice music though through the cassette port.

[apis]

I noticed there's an FX 991ex emulator you can download on the CASIO web site. I though I'd have a play around with it before deciding if I want one but I failed to get past their incredible software licensing system.

I figured it out. The trick is to ignore all the on-screen instructions and press 'cancel' when it asks you for the license code. 

Thanks!

Have played with the emulator for a while now and the complex number mode is a bit limited, you can't take the square root of complex number for example, can't use complex numbers in matrices and so on. The 5800P looks like it would be more powerful but there is no emulator for it, and it's not perfect either. I might just go with the 991ex anyway, it's nice enough and cheap, for more complicated stuff I'll probably have to switch to the computer anyway.

[Godzil]

About the timelapse feature and the SJ4000, I bought one because I need a cam for making timelapse and bougth the non Wifi one because I though it would have the same option as the Wifi one, and I don't really need Wifi for this

But, in fact the non Wifi is capable to takes timelaps photo, it take them as photo and not as a video, but if you have the correct tools it's not a real problem. So hopefully, with a delay of 5/10 or 20s between each shot, it's possible to do a timelapse with the non Wifi SJ4000

[pickle9000]

About the timelapse feature and the SJ4000, I bought one because I need a cam for making timelapse and bougth the non Wifi one because I though it would have the same option as the Wifi one, and I don't really need Wifi for this

But, in fact the non Wifi is capable to takes timelaps photo, it take them as photo and not as a video, but if you have the correct tools it's not a real problem. So hopefully, with a delay of 5/10 or 20s between each shot, it's possible to do a timelapse with the non Wifi SJ4000

I know dave has touched on most stuff but I'd like to see the camera / audio gear an a quick overview of a shoot / dub and computer editing session.

[Harrkev]

I guess I am Dave approved.

Not with that TI you ain't 

Real men use HP calculators.  RPN is for engineers!

[tjringsmose]

150 bucks for the bowtie?, hell no, funny novelty but not at that price

I was thinking the same thing. A quick check on digikey says the 67 LEDs are about 7-8USD in total, if you're not that picky. Then theres a weird shape PCB, a µC and some difficult mounting, but 150 bucks??

I'll give it a month before this pops up a 20USD including shipping on ebay - sorry to the kickstarters, it's a neato idea, but it's easily duplicable and extremely overpriced.

[Godzil]

I suspect that the LEDs are Adafruit NeoPixel and they are really cost, 67 LEDs cost much more than US$6-7

Look on digikey: http://www.digikey.co.uk/product-search/en/optoelectronics/led-indication-discrete/524729?k=WS2812B

2.3 each for 10 of them so 67 * 2.3 = $154,1...

[Fungus]

I suspect that the LEDs are Adafruit NeoPixel and they are really cost, 67 LEDs cost much more than US$6-7

Adafruit neopixel are just WS2812 LEDs.

Look on digikey: http://www.digikey.co.uk/product-search/en/optoelectronics/led-indication-discrete/524729?k=WS2812B

2.3 each for 10 of them so 67 * 2.3 = $154,1...

http://www.ebay.com/itm/261844102963

[Godzil]

Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

[coppice]

Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

Clearly the most important quality of a throw away novelty item is a 5 year warranty, and not a low price.

[Godzil]

And even if the eBay cheap version, $1 per LED will be $67. That's still far more than the $6-7 claimed earlier.

[Votality]

Dave? WTF 

[Fungus]

Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

All the WS2812 LEDs are made by World Semi as far as I know. Adafruit, eBay... all come from the same factory.

http://www.world-semi.com/en/Driver/Lighting/WS2811/WS212B/

Here's Adafruit's datasheet: https://www.adafruit.com/datasheets/WS2812.pdf

What does it say at the top of the page? "World Semi".

[Fungus]

And even if the eBay cheap version, $1 per LED will be $67. That's still far more than the $6-7 claimed earlier.

The eBay ones are 10 cents each in quantity. You can probably get them even cheaper if you buy direct.

[Godzil]

Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

All the WS2812 LEDs are made by World Semi as far as I know. Adafruit, eBay... all come from the same factory.

http://www.world-semi.com/en/Driver/Lighting/WS2811/WS212B/

Here's Adafruit's datasheet: https://www.adafruit.com/datasheets/WS2812.pdf

What does it say at the top of the page? "World Semi".

and? The eBay seller tiaochongyi  is not World Semi.

Have you ever heard about fake components, or second hand, or factory rejected chips?

For a small quantity toy, or non professional product, buying on eBay, maybe (even if I will never do that unless that's the only way to buy the component) but for something that have to be manufactured, there is no way to buy from such an unreliable service.

And digikey/mouser are not the cheapest distributors, for sure, but digikey list this component for $2.3/each, mouser they are at $4.03/each when buying, for both sellers, at least 10 of them.

And this eBay guy is able to source them for $2.90 the whole 10 packages (so 0.29/each) ?
Sorry but that look likes too good to be true.

[Fungus]

Have you ever heard about fake components, or second hand, or factory rejected chips?

Sure, but google for "fake ws2812" doesn't come up anything.

And this eBay guy is able to source them for $2.90 the whole 10 packages (so 0.29/each) ?
Sorry but that look likes too good to be true.

You might be right if it was only one seller but 20 cents per LED is a fairly typical price for WS2812 LED strips on eBay, and has been for a number of years. In fact you could get the older WS2812A LEDs for that much and they were more expensive (six pins on each LED instead of four)

For raw LEDs in 1000-quantity reels you'd expect it to be cheaper. 10 cents each is perfectly reasonable.

[Muttley Snickers]

Dave? WTF 

Unconfirmed rumour has it that they have added gambling tables to the supporters lounge and a few lost all their chips, others lost a lot more and went home counting their blessings.

[max666]

 

[old gregg]

talking about the vactrol shirt, I wonder if Dave watched "I dream of wires" documentary.

Funny how all that modular synth sounds so esoteric when you do know about it 

[senso]

Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

All the WS2812 LEDs are made by World Semi as far as I know. Adafruit, eBay... all come from the same factory.

http://www.world-semi.com/en/Driver/Lighting/WS2811/WS212B/

Here's Adafruit's datasheet: https://www.adafruit.com/datasheets/WS2812.pdf

What does it say at the top of the page? "World Semi".

and? The eBay seller tiaochongyi  is not World Semi.

Have you ever heard about fake components, or second hand, or factory rejected chips?

For a small quantity toy, or non professional product, buying on eBay, maybe (even if I will never do that unless that's the only way to buy the component) but for something that have to be manufactured, there is no way to buy from such an unreliable service.

And digikey/mouser are not the cheapest distributors, for sure, but digikey list this component for $2.3/each, mouser they are at $4.03/each when buying, for both sellers, at least 10 of them.

And this eBay guy is able to source them for $2.90 the whole 10 packages (so 0.29/each) ?
Sorry but that look likes too good to be true.

If you are into serious production you contact the manufacturer and order a reel or 10, and there is SO much people using the ws leds, they are not hard to get, they are no exotic or rare, just buy them, oh and dont pay 10x the price because it has a flower in it 

[Fungus]

This just arrived in the post...looks like it's the same seller!   




(See video at 27m44s if you don't get it...)

[Godzil]

What have you ordered?

[Fungus]

What have you ordered?

I actually ran the emulator for a couple of weeks on my desktop to see how well it works. In the end I thought "why not?", it's only $25 delivered.



Now it's here...first impressions are a bit mixed. The red/blue writing above the keys is very low contrast against the shiny faux-carbon-fiber casing. Kinda hard to read. The keys also have very little travel.