@Eric24 The debug messages at startup, before the micropython interpreter starts, are not stopped, but this is not a problem for me. No further debug messages are output once the python interpreter is started, unless the system throws an error. The startup debug messages are output at 115kbs. To stop the debug messages, my understanding is that one can compile a custom image with debug messages disabled, but I have not attempted this as they are not hampering my application.

@michalt38 said in UART handler error: I've got WiPy 1 I can not help more because i have only Wipy2.0. Maybe someone else...

@robert-hh Thanks a lot! :)

Any news regarding RTS/CTS flow control? In my opinion it still does not work.