SMC diode direction

Chimrod, 6 months ago

Thanks all for your comments and answers, I’ve just tests the keyboard and it seems to work pretty fine, I’m really happy, I didn’t expect to get something working directly! https://jlai.lu/pictrs/image/b0e09ad1-a2fb-4654-820a-faf087124329.jpeg

As a reminder, here is the commands I’ve used to get the firmware to copy:

<span style="color:#323232;"># Install the required compiler
</span><span style="color:#323232;">sudo apt install gcc-arm-none-eabi
</span><span style="color:#323232;"># Enter in the virtual environment
</span><span style="color:#323232;">. ~/.virtualenvs/qmk/bin/activate.fish
</span><span style="color:#323232;"># Check the keyboard
</span><span style="color:#323232;">qmk list-keyboards | grep sofle
</span><span style="color:#323232;"># Check the keymaps
</span><span style="color:#323232;">qmk list-keymaps -kb sofle_choc
</span><span style="color:#323232;"># Compile
</span><span style="color:#323232;">qmk flash -kb sofle_choc -km via -e CONVERT_TO=promicro_rp2040
</span>

maxmalrichtig, 6 months ago

Yes. You see that triangle with a line on top of it on the PCB? The line on your diode should be on the same side as the line on that marking.

Diode direction from Wikipedia

evo, 6 months ago (edited 6 months ago)

AFAIK orientation does not matter as long as it is consistent across the entire board. Double check with the PCB designer/manufacturer.

Edit: Why exactly am I being downvoted? What I said is correct. Hope it helps somebody as adding one line to the firmware is trivial, especially as compared to re-soldering.

Morphit, 6 months ago

While true, you would have to change the firmware to swap column and row polarity if you reverse all the diodes e.g. #define DIODE_DIRECTION ROW2COL in QMK. Conventionally, QMK assumes rows are on the cathode side of the diodes and drives the columns high. ROW2COL reverses that so that the rows are driven high and columns scanned instead.

It’s best to stick to the convention so you avoid surprises.

Nibodhika, 6 months ago

Should be, that’s the orientation I solder mine and it works.

jjagaimo, 6 months ago

It should be but to be 100% sure you should check the schematic/PCB layout and the datasheet for the part. It’s extremely rare for a part like a diode to have a non-standard marking pattern so this would be correct, but it’s not unheard of.