Hey! I'm trying to communicate trough serial between my Arduino UNO and my Arduino Nano by the TX and RX pins, and it seemed to work fine at first, but now it seems like they frequently loose the communication from each other. Sometimes it works, and sometimes it doesn't. However, when I plug in USB to one, or both of the boards, while still using one of the TX/RX pins, they're always able to communicate with each other. Both board do also work when just communicating with the computer and not between the two boards. Since it seems to work with the PC, I'm afraid that there's a defective RX/TX pin on one of the boards.
Do anyone know what could cause this problem?
Thanks in advance