Gotcha, makes sense. I'm using it to read files from the SD card. Unfortunately, I've tried the following without luck:
- Keep XDCS connected to pin 11, use pull-up resistor (100k to 3V3)
- Keep XDCS connected to pin 11, use pull-down resistor (100k to GND)
- Connect XDCS directly to 3V3
- Connect XDCS directly to GND
The first two let it continue working in general, but did not solve the problem of randomly causing all execution to halt. The last two did not work at all, which I think makes sense. #3 would cause it to never see any commands, #4 would cause it to read all commands over SPI, which means it would mistakenly process commands meant for the SD card that is also on the wing. At least, that's my understanding of how this works (I haven't done much with hardware before, and this is my first Arduino project).
I guess the question is, if it is a problem of floating values, are there other lines that could/should be pulled up/down? Or, is there a way to regain control after the program basically stops running?