51822 UART communication

[jixing.zou]

Hi All I has two nrf_51822 boards for uart communication. Use USB supply power to first, then first board supply power to second. When power on, it could communicate by uart. But if I power off second board,then power on, the first boad will can't recieve data even if second board had sent data. if reset first board, communications back to normal. Somebody in this kind of problem?What reason causes this problem?

[Knut Eldhuset]

Can you show us the code you use to set up the UARTs and send/receive on both boards?

[chad.ou]

I also encountered a similar situation, and then through the analysis, the test is found UART RXD pin level does not match.