Updating AVR fuses on Megadesk

[gcormier]

After some discussion it was determined that there are better fuses available to prevent EEPROM issues (forgetting memory positions) for users who are killing the power to their desk and experiencing the issue. (Not all users experience this symptom)

To fix this yourself:

1. You need an AVR programmer. I talk about it here a bit. There are many options on Amazon, etc. You could even try to use a Raspberry Pi as an AVR programmer I can't help you with AVR questions as there is a TON of information online as well as helpful forums that can help you with programmer AVR's aka "Arduino".

2. We aren't actually uploading new code, but changing the fuses rather. The tools and connections are all the same.

3. In general, your megadesk should only receive power from 1 source. This will depend on the programming device you purchase.

4. You don't need to solder. Depending on the cables provided, if you have a standard 6-pin AVR programming cable, you can use a 6-pin header, and simply hold/wedge the pins in the megadesk PCB during programming.

5. Note it is unlikely, but possible to brick your device if you enter the wrong fuse settings.

6. With your megadesk/programmer connected properly, you can updated the fuses with

avrdude -c usbtiny -p t841 -U hfuse:w:0xd4:m
avrdude -c usbtiny -p t841 -U efuse:w:0xf4:m

You might need to adjust the parameters slightly depending on your programmer and your setup, but the hfuse and efuse should not be changed.

Sample 6-pin header image (keywords to purchase - 2.54mm 6pin 2x3 male header)