Sending data from Jetson TX2i with serial port (UART0 => ttyS0) to the target serial port device is OK but when I try to send data from the target device to Jetson TX2i, data did not receive in ttyS0 instead of this data echo in target serial port device.
TX2i ttyS0 => target serial port : OK
target serial port => TX2i : did’t receive in ttyS0 instead echo in target again!
I tested another serial port with the same cable but it’s OK just UART0 (ttyS0) has this problem (also checked in another developer board but it didn’t fix)
This sounds like the serial console port. What do you see for the group in “ls -l /dev/ttyS0”? If group is dialout, then you are free to use this, but if group is tty, then the port is already in use by serial console.
If you wish to disable serial console (only needed if group is tty), then:
(at this point the ttyS0 group would revert to dialout)
If that wasn’t the issue, then make sure both sides of the connection have the same settings, e.g., make sure neither side has enabled CTS/RTS flow control, and that both sides are 3.3V and not some other voltage level.