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Found the original lid
Also had to trim the pcb corners the mounting holes don't interfere.
Unfortunately the decals did not come though, and the cylinders on top of the buttons dissapeared.
What's interesting is that there are pcb spacers on the lid as well. So using these is possible as well.
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The punches are available off the shelf, and are even available in profiles for most common switch holes ( flat sides and with a notch for alignment) quite cheaply. Of course the major issue is that the substrate will have to be heated to around 59C to prevent cracking on thick panels or brittle plastics. If it is to be a custom punch they generally are made by using a copper negative master in a spark eroder to etch a tool steel bar to the required profile. Slow but makes a near perfect hole.
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if you are going to produce these in quantity : have the lid laser cut or waterjetted. that can be done for a few dollars per unit...
Why not custom mill an enclosure. the guys from Salae can have it done for their products. they buy a few hundred at a time in china for 4 to 5 dollar a pop ... then you can have a nizce anodiced , custom shaped enclosure with all the holes cut in it. you can even engrave the legends .... -
One thing about that display. With the configuration of a triple-decade display with (obviously) low duty cycle, it becomes possible to use a column-amplified Charlieplex configuration, so that 30 of the LED's are addressable with only six pins.
Only the tens-(digits) need to be connected separated from the main array. Only 6 pins with three-state addressing, three NPN transistors, nine resistors for 30 of the LED's. Add two more LED's, two resistors, and two more pins for the tens place and Bob's your uncle. Almost exactly what I have done for my bidirectional LED optics project. That could substantially reduce the part cost for the MCU in a huge way.
J.R. Stoner
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Following up to my own post (bad form, really) You could use differently-colored LED's within each of the decade columns in small groups to aid readability. Pick five colors and use groups of two:
wht red red org org ylo ylo grn grn blu blu (white can be the decimal point or the tens digits).
J.R. Stoner
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What about a row of LEDs that represent 1-15 volts(or whatever the max voltage is)
Then another row of LEDs underneath that represents the tenths of volts (0.1, 0.2, 0.3,etc..)
I'd personal think it would be easier to read than the matrix design. -
Hi
First things first the LED decade is a nice idea and a practical one (i really liked my LED wrist watch
), still regarding the USB supply i have a hint about a possible option and i hope it will make a difference for David ... but the are 2 uneasy details.
1. It is a 1bit B/W graph LCD 96x64, with LED backlight (extremely popular NOKIA LCD spare)
2. It is available at a good price on Alibaba (China).
the good aspects about this solution are
1. the fact that it's cheap 0.70$US /100 (one hundred pcs), above 1k i saw that is possible to shave off about 9-11 cents
2. has SW support (i used it with cortex M0/M3 but HAL drivers for atmega can be made)
3. needs only 4 wires for data SDA/SCL/RST/CE
4. there 2 display options one with solderable flex PCB type connector, another with hirose DS-10 connector both share the same physical layout and dimensions
5. the DS-10 connector version has a very neat 4k color upgrade option (another LCD from nokia)
6. IMHO this LCD will be around at least for the next 5 years.
If this can be usable i would be more than happy to provide the details
Best regards
Ovidiu -
Regarding the switches, can you price justify a micocontroller with touch capability and
do without mechanical switches and have touch pads instead?
The design would be free of moving (read breakable) parts and be easier to place where you want them.
You can't have touch switches unless you have an active PCB for the front panel.
Dave. -
If this can be usable i would be more than happy to provide the details
Yes, please supply the supplier details.
Thanks.
Dave. -
It is a 1bit B/W graph LCD 96x64, with LED backlight (extremely popular NOKIA LCD spare)
Something like that could possibly be attached to the PCB over the top of the unpopulated pads for the decade display.
If the supply of the LCDs ever ran out or there were issues getting them they could be left out and the original decade leds soldered on instead. -
Just had a look at the prices for the Nokia LCD displays on Aliexpress, and they seem to be ridiculously low. 320x240 serial interface colour displays for a few dollars. I didn't see the $0.70 displays, but it was easy to get under $2 for just 10 off quantities including shipping for monochrome displays.
Is this a real price, or has the Nokia production crashed so far that the market is flooded with displays. It seems to me that the bulk of the cheap displays are Nokia.
I wonder how long these prices will last? It is hard to know. Considering the size of Nokia and how quickly their sales have been dropping, there could be warehouses swimming in unused displays. -
I don't see the $0.70 ones either, more like $1.20 - $1.50 or so which is still quite cheap.
But there are just so many variants it seems endless...
I think the trick if you design one of these in is to find someone with 5K+ and negotiate a price for the whole lot!
Dave. -
Just got a quote from a local plastic place for the custom polycarb cover, $2.40 for 1000. That's seems fairly expensive to me?
Anyone know any good places that can do it cheaper?
Dave. -
The Nokia 5110 displays seem nice, and appear to come attached to a small board with 0.1" header. Much easier to use and mount than the others.
But about double the price what I can get the 8x2 line LCD modules for.
Dave. -
Just got a quote from a local plastic place for the custom polycarb cover, $2.40 for 1000. That's seems fairly expensive to me?
Anyone know any good places that can do it cheaper?
Dave.
Given the tiny quantity it is actually a good price, considering that they have to make molds for it.
Have you considered having a sheet metal lid? Given the original case that you are using it will be possible to have a very simple and robust single piece lid like below. You might want to inquire a sheet metal place for something like that. It might come cheaper as it has only two bends and one laser cutting (or blanking, even cheaper) operation. Hell the bend operation could even be ganged up so as to have 2 bend operations for every 20 pieces
1.5mm aluminium would be suitable material.
If interested I can draw it for you in no time.
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This is very interesting. Dave walks out with an idea and he got blown up into pieces. What else is a community for?
I am happy, but I am also sad. I think the main reason (since I don't really need a USB PSU) for the product was for the amusing display aspect of it with the low cost factor. Now just a 'normal' tool. Though a little more stable with the community. Still interested.
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Given the tiny quantity it is actually a good price, considering that they have to make molds for it.
No moulds, they just cut it out from a larger sheet from stock. It's square with 7 holes in it. Probably the simplest thing possible for them.QuoteHave you considered having a sheet metal lid?
Not really, I don't fancy that at all.
Dave. -
No moulds, they just cut it out from a larger sheet from stock. It's square with 7 holes in it. Probably the simplest thing possible for them.
Sounds to me like the perfect excuse to buy a laser cutter
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Sounds to me like the perfect excuse to buy a laser cutter
An A3 sheet of 2mm clear lexan polycarb is $7.30 on ebay ($4.80 for A4 size).
I could laser cut at least 20 from one A3 sheet, so that's $0.36 ea
Assuming I could get a cheap laser cutter that could handle sheets that size...
Dave. -
Hi;
check this out:
I think it turned out well.
Mick M -
Not really, I don't fancy that at all.
Well my idea bag is empty now
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Hi;
check this out:
I think it turned out well.
Yes, I do PCB front panels all the time.
I kinda had my heart set on a clear top to see the circuitry for this, but maybe not...
Dave. -
I think it would be too distracting to have to read this kind of display, what about an LCD with a shift register? There is an article posted in EDN magazine, EDN Access--12.18.97 LCD interface saves mC I/O pin, EDN Staff- December 18, 1997, Robert Wells, ETR, Moab, UT which takes this approach. I checked Digikey and the 74HC164 is selling for around 0.13 cents in 2000 quantities.
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I think it would be too distracting to have to read this kind of display, what about an LCD with a shift register?
The choice of LCD has nothing much to do with LCD pins if you use a module instead of segmented display.
It's mostly about cost, mounting etc.
I am liking the module over a segmented version. More info, and possibly cheaper. Just a matter of which one and how to mount it and how to do the front panel.
Dave. -
Silly question from a 'young player' ... err make that complete newb. Where can you get LEDs for 1 cent each in 1000 quantities (thats what I recall Dave saying in the video)? I checked mouser and digikey... the cheapest I could find was around 4 cents. That is a pretty dramatic difference.