I’m building an RFID reader using a great little board from Priority1 Design. This board provides me with regulated 3v3, which I drop into the top-right pin on the Core ( VCC / pin 24 / labelled 3v3 on the board ). The RFID board and the Core share a Ground. It then communicates to the Core over serial, the pin labelled RX on the Core. We’ve tested this for several days, during which they happily work together and the Core sends me RFID data over the Cloud. All in all, it seems to be great.
Yesterday, however, it seems like the Core fried. This wasn’t during “standard use” - I’d given it to others to scan some RFID tags, and I’m not quite sure what they did with it, but the Core currently doesn’t light up when rebooted or plugged in directly over USB, and just gets very hot. My solder looks like it’s holding fine and I can’t see any short-circuits.
Any thoughts on what may have fried the Core ? There’s a small chance it somehow fried when it was disconnected from its power supply and then plugged in over USB to diagnose what was going wrong, but from what I understand, it was already not booting after being power-cycled through the RFID board - that is, it stopped reading, so they unplugged the power supply at the wall and plugged it back in. Again, the power supply provided to the Core into Vcc is 3v3 regulated, from the RFID board, which we feed with a 12V wall wart. If anyone’s interested, it’s this beast - http://www.priority1design.com.au/rfidrw-e-ttl.pdf
Any thoughts, advice, opinions appreciated. Thanks !