Jetson Xavier AGX Test 40 pin hesder for UART RTS/CTS


I’ve been trying to use my AGX to test 40 pin header, I set pin11 was RTS by using Jetson-IO, and I prepared NANO 40pin to test, I connected their Tx/Rx/CTS/RTS, then use the minicom, the hardward flow control is Yes,then I disconnected RTC or CTS, they still can send the message to each other.

Does the step anything wrong?Does anyone can help me??

hello edward1_lin,

could you please confirm you have update these pin configuration from GPIO to SFIO, (i.e. UA3_RTS/CTS)
after that, are you able to probe the signaling, did RTS/CTS actually works correctly,
for example, RTS line to be high during the entire transmission before dropping.

Hi Jerry,

I’m using Jetson-IO to check my pin define.


After set up, I check the voltage to those pin, befor I open the minicom, pin11 is 3.3V and pin36 is 0.06V, after I open the minicom pin11/pin36 are both 0V.

Is it correct? Are these information enough? If you need more information, please let me know.

hello edward1_lin,

please check the pin state by sending serial data through this UART port.
RTS line to be high during the transmission, thanks

Hi Jerry,

I was using my digital multimeter to connect the RTC and GND, It was the same result as my first reply, when I set up the pin11 to RTS and reboot, I check the Voltage, It was 3.3V, after I open minicom, and hardware flow control set to Yes, the voltage changed to 0.0V, then I sent some message to other device, the voltage still be 0.0V.

The reaction is not same as you said, Is there anything I need to check ??

Hi, you’d better to use an oscilloscope to observe the RTS signal not a multimeter.