RC7620-1 fails to use (UART interface) CMUX in Linux


I fail to use (UART interface) cmux in Linux.
It response “cmux: Cannot read /dev/ttyUSB0: Resource temporarily unavailable”
Similar “read” has some problem.

Below is cmux.c write and read code screenshot.Please refer to the attached cmux.c

cmux.c (9.4 KB)

Please advise how to process it.Thanks

Hi all

Any suggestions?


So a couple of things:

  • Make sure you are on R8 as a minimum, ideally one of the latest R9 beta versions which you should be able to get through your commercial channel (distributor).
  • Have you made sure at!muxmode=1?
  • Presumably you are able to run minicom against /dev/ttyUSB0 and get to the AT commands?