Which tty for which UART?


I’m trying to communicate through UART1 on my WP710x devkit, but I’m unable to find which device in /dev/ is connected with UART1 (or UART3).
There is more than 300 others tty* in /dev/, I found that UART2 is /dev/ttyHSL1 but nothing for the others.
There is a ttyGS0 that make microcom freeze each time I try to connect it, so I can’t find if it’s used for an UART.

Does anyone have a clue for me ?



/dev/ttyHSL0 is uart 0 … but it’s usually connected to the serial console at boot time, and is not available for use as a serial port.

There is a way to disconnect it from the console, but unfortunately I can’t remember how to do it off the top of my head. Sorry.

Ciao, Dave


I don’t have ttyHSL0, I only have ttyHSL1, ttyGS0 and a lot of tty1 to ttyzf.
my ttyHSL1 is the one used for serial console.
It seems that something is wrong somewhere. :frowning:


To setup the role of each UART port, you have to use the AT command “AT!MAPUART”.

In your case, only UART2 (ttyHSL1) is activated in linux console mode.
If you want to have UART1 (ttyHSL0) activated in linux “raw data” mode then you have to send the AT command “AT!MAPUART=17,1” and then reboot your target.

echo -e "AT!MAPUART=17,1\r" > /dev/ttyAT reboot
After the reboot you will have a /dev/ttyHSL0 port available to manage your own data/protocol on the UART1 port.


Ok, something went wrong,
I don’t have ttyAT either.


I re-flashed all system and I finally got ttyAT
so I now have entered the AT command you sent me and I now have my ttyHSL0 working on UART1

Thank you.

PS : where can I find an list of AT commands ? I can’t find this on the Legato doc.

AT commands are generally specific to the product (to some degree anyway). You can search for the document you need at source.sierrawireless.com.


That’s what I did, but I never found it.
I read on other topics that we have to ask distributor for it.