I am trying to have an RT1020 and RT1050 communicate with each other via UART. Specifically, LPUART8 is used on the RT1020 and LPUART3 is used on the RT1050. Both boards are being powered by USB connectors.
If the connections between the two boards are added after both have been powered up, everything works fine. However, if the two board are connected and then powered up, only the first one that was powered will function correctly. The other board goes into maintenance mode and will not run its program.
Any ideas what would cause this?