Go to settings (press Ctrl+A, then O), select Serial port setup, set port /dev/ttyGSM,set speed and parity - 115200, 8N1, Hardware flow control - No, Software flow control - No
Save settings: Save setup as _dev_ttyGSM
Then run as minicom /dev/ttyGSM (all settings will be taken from the profile name /dev/ttyGSM that we previously created)
Your first command should be AAAAAAAAAT - the module automatically detects the communication speed (see SIM900R)
With the second command, simply run AT. You should get the answer OK.
