HP (@banjohat)The problem with real life is that it tends to get in the way of your projects.
This update is far overdue - sorry for that! The paying projects (my job amongst other things) has been taking up most of my time. Also I'm leavning for a much needed vacation in a day. This all means that I won't be back until July to continue work on the soldering pen.
So what have I managed to get done?
Last time I wrote I was ordering PCBs. I have those - I've had them for a good month now. The trouble is programming the MCUs! I feel that I have tried everything. I have tried to solder all pins under a microscope securing all connections. I have assembled 6 boards but NO luck!
I have only put on the MCU and the ICSP header. That should give me both SPI access and power for the MCU. But I must have been doing something wrong on the design.
I have looked through the schematics but again - no luck. Everything seems to be in order - except is isnt. Could it be the MCUs? Maybe. I have them stored in a tray without any control of moisture. the tray is of the type with a small indent to keep each chip in place. a chip tray. it should be good enough, however I can't vouch for the chips. but that would mean that all my chips are fried. not a pretty thought.
I know that this project has gotten a fair amount of followers since the start. Maybe some of you would like to have a look at the design? If you find an error I will send you a working PCB :)
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Maybe that's too obvious, but did you checked your fuse settings when programming? Especially the clock source fuses? What's the exact problem with programming? Does it not return a device signature?
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That's not obvious at all and is a really good comment! The board (from boards.txt) is the following (added an entry to the pro mini section):
pro.menu.cpu.Custom=ATmega168p NO OSC
pro.menu.cpu.Custom.upload.maximum_size=14336
pro.menu.cpu.Custom.upload.maximum_data_size=1024
pro.menu.cpu.Custom.upload.speed=19200
pro.menu.cpu.Custom.bootloader.low_fuses=0xe2
pro.menu.cpu.Custom.bootloader.high_fuses=0xdd
pro.menu.cpu.Custom.bootloader.extended_fuses=0xfe
pro.menu.cpu.Custom.bootloader.file=atmega/ATmegaBOOT_168_pro_8MHz.hex
pro.menu.cpu.Custom.build.mcu=atmega168
pro.menu.cpu.Custom.build.f_cpu=8000000L
Any comments to this is greatly appreciated! I have tried both atmega168 and atmega168p as mcu type...
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Ok, and you're trying to install the arduino bootloader via ICSP, or directly uploading a sketch? Did you select the correct programmer (Arduino as ISP, I guess?) I can't see any hardware problems as the design is really the absolute minimum, so I'd definitely guess it's an software issue. I think the fuses settings look good.
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I'm skipping the bootloader since i'm not having any serial communication anyway. Yes, I'm using the arduino as ISP.
Thanks for verifying the fuses! It could even be my arduino installation. I should try and reinstall it all (maybe run directly from a zip file..) My boards.txt is located in a weird folder anyway :/
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Taking your words literally; if you only mounted the MCU and ICSP header, you might have forgotten R6 to pull the reset pin to high as a low (/floating) level on that pin triggers a reset? Or is the reset pin always actively controlled by the ICSP programmer when connected? Possibly it is simply a drain on the other side which cannot drive it high :-)
To be honest, I can't imagine much more faults as your design is quite simple (which is a good thing!) and it did function in your earlier version.
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Ah, This was the comment you mentioned!
As far as I know the reset pin should be push-pull controlled by the ICSP (an arduino in my case)
However, I have also tried to mount a 10k pull-up between reset and VCC just to see if that made any difference. It didn't.
Yeah, I have been baffled by my problems with this design as well! I have some 16MHz MCUs I can mount because maybe the other ones I have had lying around for a long time have been destroyed by moisture..
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Ah, that's a pity... as I said I really can't imagine what else could be wrong then. Good to hear from you anyway, good luck with the further debugging!
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