I have seen many posts about reviving a bricked pro micro from bootloader. I’ve tried this by double-clicking the reset button on my qwiic pro micro twice and then quickly uploading code. I’ve tried a blank sketch, a simple LED light sketch, etc. Each time, my code takes too long to upload, and then 8 seconds pass and my microcontroller loses the port before the code can upload. I also remember that my qwiic pro micro did take a while to upload code while it was working. I’m not sure what bricked it in the first place, since I’ve always had the correct frequency (5V, 16MHz) in the tools tab. Does anyone have any thoughts on how to revive my microcontroller?
Do you happen to have an AVR programmer (to re-flash bootloader)?
If the steps linked above don’t work, also remove & reinstall drivers…finally if that doesn’t work, we offer a 30 day warranty on all items - if within that period, head over to Return Policy - SparkFun Electronics if purchased from us, or contact vendor for similar if purchased elsewhere
Thank you for your response. I was able to finally get the microcontroller unbricked after trying the procedure many times. I do not have an AVR Programmer. However, I have run into a new issue. I have to change the soldering on the back of the board from 5V to 3.3V, and have now bricked the microcontroller again, likely due to my IDE still being on 5V,16MHz. I’ve tried to unbrick again using the same procedure, but have run into a strange issue. When in bootloader mode (after pressing reset twice), and uploading the code, we are able to upload code by pressing the reset button twice again while the code is uploading. We are able to run code but still don’t see a COM port and now we no longer have serial connection. Is this a phenomenon anyone has run into before?
Changing the jumper won’t change the board type. If you bought the 3.3 volt board you have to always program it as the 3.3 volt board definition even if you’ve modified it for 5 volts. (Vice versa for 5 volts / 3.3 volts)
The reason for this is the 3.3 and 5 volt boards have different crystals on them and a part that goes on the board along with your sketch sets up the boards clock’s to match the crystal. If you program a 3.3 volt board with the ide set to 5 volts, it will take the code but now the clock is set wrong and USB will stop working resulting in no COM port.
Fix is the same procedure as before, keep resetting and uploading another sketch with the correct board definition. Once you get the timing just right and the sketch uploads, you’re back in business.
