# FX30s - Using UART1 & 2 in legato app **URL:** \ **Category:** FX30\ **Created:** [June 24, 2019, 2:35pm UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756 "2019-06-24T14:35:48Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![bastien0530](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@bastien0530](https://forum.sierrawireless.com/u/bastien0530)\ **Post date:** [June 24, 2019, 2:35pm UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/1 "2019-06-24T14:35:48Z")
Hi everyone ! I am a new user of the modem FX30s and the development platform legato. As an introduction, I already successfuly experiment some basics applications like HelloWorld or blinking debug led with timers. But now I would like to develop an application which use UART1 & 2. My project consist in developping the software who spy the AT command communication between a datalogger and the modem and send some of these on an IOT Lorawan card (UART2). Actually I tried a simple echo on uart1 mode rs232 (!MAPUART=15,1). I can builded and installed the application on the FX30 but I can’t launch the app (Application ‘UART\_Test1’ is not installed. However when I check with app status, I can see the application with the state [stopped]. My software is the same as [https://forum.legato.io/t/legato-serial-communication-fx30s/3287/3](https://forum.legato.io/t/legato-serial-communication-fx30s/3287/3) , I just changed the component.cdef with [rw] /dev/ttyHS0 /dev/ttyHS0. Secondly, I would like to know if there is a chance to perform AT commands with a legato app because of the requirements of my application. Best Regards, Bastien ---
**Author:** ![cchenry](https://avatars.discourse-cdn.com/v4/letter/c/a183cd/32.png) [@cchenry](https://forum.sierrawireless.com/u/cchenry)\ **Post date:** [June 25, 2019, 2:20am UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/2 "2019-06-25T02:20:46Z")
Hi Bastien, Please monitor the log by typing “logread -f” In a separate session, try starting your app: app start UART\_test1 Then you can see the logs why your app isn’t starting. You can send AT commands from your app if you open /dev/ttyAT BR, Chris ---
**Author:** ![bastien0530](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@bastien0530](https://forum.sierrawireless.com/u/bastien0530)\ **Post date:** [June 25, 2019, 9:17am UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/3 "2019-06-25T09:17:41Z")
Hi Chris, Thanks for your reply, I had this log, it seems that the modem can’t find the tty file for HS0 : Jun 25 09:07:04 fx30s user.err Legato: =ERR= | supervisor[524]/supervisor T=main | app.c GetDevID() 629 | Could not get file info for ‘/dev/ttyHS0’. No such file or directory. Jun 25 09:07:04 fx30s authpriv.info dropbear[3284]: Exit (root): Disconnect received BR, Bastien ---
**Author:** ![cchenry](https://avatars.discourse-cdn.com/v4/letter/c/a183cd/32.png) [@cchenry](https://forum.sierrawireless.com/u/cchenry)\ **Post date:** [June 26, 2019, 4:27am UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/4 "2019-06-26T04:27:35Z")
Hi Bastien, I assume you’re running R14.0.4.002. Can you please check if the ttyHS0 device does indeed exist? Did you reboot after the mapuart=15,1 command? BR, Chris ---
**Author:** ![bastien0530](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@bastien0530](https://forum.sierrawireless.com/u/bastien0530)\ **Post date:** [June 26, 2019, 12:24pm UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/5 "2019-06-26T12:24:34Z")
Hi Chris, Thanks for your help ! Apparently the problem was my firmware, now it’s work. I have a last question, Is there a way to communicate to the /dev/ttyHSL1 from the linux shell? I thought I should use microcom -s BAUD\_RATE /dev/ttyHSL1 on the FX30S but that doesn’t work. BR, Bastien ---
**Author:** ![cchenry](https://avatars.discourse-cdn.com/v4/letter/c/a183cd/32.png) [@cchenry](https://forum.sierrawireless.com/u/cchenry)\ **Post date:** [June 28, 2019, 2:58pm UTC](https://forum.sierrawireless.com/t/fx30s-using-uart1-2-in-legato-app/16756/6 "2019-06-28T14:58:11Z")
Hi Bastien, You can try using “echo” or “cat” but I would recommend this only for testing or for a short script. BR, Chris