Hi

I'm going use the terminal armbian and send AT commands to the gsm SIM800L, but I am uable to write these commands.
I used screen and minicom like this :

screen /dev/ttyS0 115200
&
minicom -b 115200 -o -D /dev/ttyAMA0

I use to connect to ttyS3 but nothing happen i think the uart3 or pins 8 and 10 is not working or not enable of course i have ttyS3 in ls /dev list but not working.

I've connected according to the following guidelines:

 

 

i use :

orange pi plus 2 board

armbian for orange pi plus 2

SIM800L v2.0

 

image of my connection and board :

 

 

There is mention of activating the serial ports in armbian documentation here:

 

https://docs.armbian.com/Hardware_Allwinner/#enable-serial-devttys3-on-pins-8-and-10-of-the-40-pin-header

 

It involves change of the fex file. Maybe this helps?

 

best, gnasch