C6 makes the board boot into DFU mode when not powered for a while
andershedberg opened this issue · 1 comments
Hi, and a big thanks for the design!
I have now build a few (with USB micro connector instead of the USB-C ) and noticed that all boards when not powered for a while, boots into the DFU mode (i.e where it expects code to be downloaded to it) as if the BOOT button is pressed. The same effect happens if the board is removed from USB power, boot button is pressed to empty the C6 charge, releasing the boot button and then connecting the board to USB (power) again.
Removing the C6 100nF capacitor solves the problem and the board boots into the flashed program. as expected.
No problem at all, I'm glad to hear it!
You make a very good point actually and in hindsight that is definitely a mistake on my part. I normally add a little capacitor with buttons like these to act as a bit of cheap and easy hardware debouncing. My guess is it's something to do with a combination of the capacitor retaining charge and the state of this IO pin on boot.