UART example on Jetson TX2?

Hi everyone,

I have been scouring the internet looking for a simple example or advice on using the Jetson TX2’s UART port. I am using a Jetson with the connecttech Orbitty Carrier board. I have notice that two UART ports are piped out to the expansion header as noted on pages 11, 12 of the manual: http://www.connecttech.com/pdf/CTIM-ASG003_Manual.pdf They even mention that these should show up as /dev/ttyS0 and /dev/ttyTHS2. I can see both of these devices but cannot figure out how to interface with the UART port.

I have tried echoing in one terminal and catting in another. I have tried screen. Is there a simple tutorial or setup guide on how to get UART working on the TX2?

Thanks!

I don’t have a tutorial, but FYI, loopback may be a better start. If you connect a UART’s TX and RX together, it talks to itself. You can also tie CTS and RTS together if you use hardware flow control. A terminal program like minicom or gtkterm will see echo if the port runs…else typing in won’t echo. Perhaps one of the bigger advantages of loopback is that you don’t need to worry about whatever device attached to it being at a compatible voltage level or not (I have no idea what Orbitty uses).

Note that if ttyS1 is serial console it would be a bad idea to wire TX/RX…I’m sure it would confuse U-Boot and kernel trying to talk to itself. On the dev board ttyS0 is serial console, I don’t know what Orbitty routes as serial console.

Most of the UARTs will probably have default of 115200 8N1, or possibly 38400 8N1. In some cases it may fall all the way back to 9600 8N1…it wouldn’t hurt to try all of those settings.