Nano UART1 received one byte less data!

Recently I encountered a very strange problem. I used the PC serial port assistant to send data, sending 8 bytes each time, and using Nano UART1 to receive data. The data received by Nano always missed the first byte each time. Nano did not send data, but the PC serial port assistant can receive a byte, which is the byte lost during transmission.

I use an oscilloscope to measure the data and the waveform is correct.

And it is normal on TX2.

hello zhanghongqiang789,

please have a try to stop and disable the nvgetty service. this starts a console on ttyTHS1.
for example,

$ systemctl stop nvgetty
$ systemctl disable nvgetty

there’re similar discussion threads for your reference, Topic 81583, and Topic 81352.

Thank you!