I have run into a problem using NVidia Jetson Nano’s UART port.
Running Ubuntu 18.04, I am using python to communicate (with mavlink messages with my flight controller), via the Nano’s UART (pins 6, 8 and 10).
Messages on the RX pin coming from the flight controller are read successfully by Nano, and I can see the voltage changing on the wire with an oscilloscope.
However I am not able to send any messages from the Nano to the flight controller, and I have tracked down the issue to the TX pin. Even if I am sending a message, it only outputs a 1.2V constant voltage (with some small noise), thus not delivering any message toward the flight controller. I believe it should output 3.3V with the voltage visibly dropping to 0V when sending messages. If the flight controller is not connected, the TX pin is on 1.5V voltage level.
I have disabled the nvgetty service as advised on other similar posts.
I have considered issues with the level shifter, too, like in this case, but I see the voltage remaining constant.
Could anyone help, what can be the reason for this?
Thanks in advance for any help!