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Topic: A failed v2 prototype (Read 5725 times) previous topic - next topic

A failed v2 prototype

I made this one with Batch PCB. They got the address wrong because of a website bug and it took months and months to get it.

The original web server on a business card was mostly single-sided, so I could do whatever with the back. I decided to add a 128x128 color Nokia knock-off LCD, a network connected photo frame. I prototyped it in several segments on homemade PCBs, so the software is complete.

The blue wire connects some power pins I forgot to route. (oops!) The unrouted wire was directly over the connecting wire, which made Eagle Cad's unrouted indicator invisible. Now I use the zoom-unrouted.ulp script to check for this before I send a board to be made.

I didn't publish this design because part availability became an issue. SparkFun stopped carrying the SD card holder I used, and I didn't want to re-do it to test another holder. The LCD also became a pain because SparkFun got a new batch that didn't work the same as the old models, which means maintaining two drivers and two firmwares, yuck.
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Re: A failed v2 prototype

Reply #1
The SOT223 regulator behind the SD card holder is an LM317 voltage regulator set to 7volts with 2 resistors. It supplies the LCD backlight.

The giant [s:]D2Pack[/s:] Dpack (?) 3.3volt regulator (LD117) also seems like a really expensive, kinda rare part.
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Re: A failed v2 prototype

Reply #2
Id be quite interested in seeing what you did with the LCD. I bought a 132x132 LCD off ebay (like this) a little while ago with the intention of adding it to my web server to display IP address etc. It's pretty cool because the board it comes with sorts all the necessary power supplies etc.. I never actually got around to it but now I've come across this forum I might dig it out again and give it a go! :D

Re: A failed v2 prototype

Reply #3
I made the DIY digital picture frame.
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Re: A failed v2 prototype

Reply #4
Ah, yeh, I'd seen that article. I thought you may have integrated the LCD on the v2 board... which is what I'd tried to do previously. It was a little tricky though as the LCD used 9-bit SPI so the code had to turn off the hardware SPI when sending the last bit. I got the LCD to work on a seperate board (same PIC) but never managed to find the bugs when I merged the code into the webserver source.

Re: A failed v2 prototype

Reply #5
Sorry, yes, I did integrate the LCD on the back of the V2 PCB. The picture frame is what I did instead.

I just used software bitbang routines rather than mess with connecting and disconnecting the SPI peripheral. I used a TCP or UDP (forget) server to received BMP files sent from a PC. Not exactly fast, but it worked.

I'm working on cleaning up my archives, I'll post this code ASAP.
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Re: A failed v2 prototype

Reply #6
Hey, just got my V2 PCB. Just to let you know, the envelope was a little damaged as you mentioned before, but thankfully pcb was still there.

Just wondering if the parts/numbers are the same/similar to the v1 on hack a day, and exactly what pins do I need to connect the jumper wires to?

Again, thank you for the PCB

Re: A failed v2 prototype

Reply #7
The part numbers and values should be the same, with these exceptions:

1. C3 is an A-CASE tantalum 10uF capacitor, the original had a mix of electrolytic and tantalum.
2. The Ethernet jack and the power jack are both on the top, they were on the bottom of the v1.
3. The power jack is a 2.1mm SMD, rather than through hole.
4. IC3 is LD1117 3.3volt DPACK, instead of LM317 adjustable.
5. As we discussed in another thread here, the SD card holder sold by Sparkfun is no longer the same as the one I used. The changed model but not part number.
6. You do not need these parts (unless you want to use the LCD screen): L2, C13, C14 (back), C16, C17 (all 0.1uF), R5 (240ohm), R6(1101ohm), IC4 (LM317-SOT223).
7. The jumper should connect the power side (chip side) of C9 to a power supply. C9 is the first capacitor below the crystal capacitor (C23). I soldered a wire from the top of the capacitor to the outside top of inductor L1.

I use the same parts in a lot of projects, you can check my Hack a Day projects for any of these part numbers.
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Re: A failed v2 prototype

Reply #8
If the pictures aren't clear, I'll also try to dig up the schematic and PCB files for this project. I have no idea where they are or what they were called for this PCB version, though.
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