Small command line utility that allows you to send SMS messages via AT commands (Hayes cmd set) through a GSM module that supports serial communication over USB in Windows.
The dongle used is GSM/GPRS SIM800C USB to GSM Serial Module (https://www.amazon.co.uk/gp/product/B08KYCMGXD). STL files to 3d print a case can be found in the Resources folder.
Usage: SerialAT.exe COM4 <international phone no> "Message"