We are planning to use Jetson TX2 UART port for multiprotocol serial port functionality using SP336 converter. please can you confirm whether auto RTS function is supported in Jetson TX2 ports? if not please is there any alternate solution?
I’ve noticed on a TX2 RTS/CTS does not work with default on either the serial console ("/dev/ttyS0"), nor with J17 (goes to the camera, but not normally used, “/dev/ttyTHS2”). I do not know if this is a hardware problem or a software configuration issue. The TX1 is able to use these with the default configuration.
UART1 from Jetson Module which goes to J17 and camera connector works fine as expected and we have enabled RTS and CTS function. When we transmit the data then RTS line will go low and it is expected behavior.
In our custom design we are using SP336 transceiver and it works fine for RS232 protocol.
When we set it to RS485 mode it expects RTS line to be high while transmitting which is not the case. When we tried to invert the RTS bit in the code, the Jetson TX2 does not boot.
Any idea on this to correct the RTS polarity for RS485/RS422 protocol?
I do not know why the RTS of J17 would have an effect on boot. My guess is that the port has some different function until reaching some boot stage, and you are inverting prior to reaching that stage. Someone else will have to answer how J17 might affect boot.