J44 serial not working

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi,

I’m trying to get the J44 serial working. Right now, the GPIO serial (J41) has no issue working (/dev/ttyTHS1), but /dev/ttyTHS1 is not even passing the “loopback tx to rx” test, and always appears as off in Minicom for example.

Do I need to disable something that is using this serial port? My goal is to exchange messages on this J44 serial port with a flight controller.

Thanks,
R

2

Hi,
There are some posts discussing about J44. Please refer to
https://devtalk.nvidia.com/default/topic/1063960/jetson-nano/j44-header-pin-as-normal-serial-port/post/5387604/#5387604
https://devtalk.nvidia.com/default/topic/1066621/jetson-nano/j44-read-reads-only-4-bytes-at-the-time-/post/5402093/#5402093

3

Yes, I tried the solutions in there: disabling the different things that output to J44, but without success: running minicom on the jetson nano, with a loop jumper cable between rx and tx, for example, doesn’t give me any output.

4

Try to also jumper CTS and RTS. If flow control is on, then missing this would block traffic.