I am having a weird issue with a board based on the ATMega328P, in which the firmware seems to "break" (stops responding to serial commands) after a little while (including being turned on and off again, a few commands sent/received each time) and can only be fixed by re-uploading the code to the micro (power cycling does not fix it). I am not even sure where to begin with sharing the code, as it is a large-ish project. Basically, it is a board using an FTDI chip to send serial commands back and forth to the micro, which then reads an ADC (MCP3204) and controls a DC motor (using a SN754410).
I was using Optiboot at first so that I could upload code over the FTDI, but I tried uploading the code directly to the micro with no bootloader, and the problem persisted. My fuse settings are L:0xFF, H:DE, E:05.
Any ideas? If there is any information I left out that could be useful please let me know. Thanks for your help!