A system for sms notificatios bases around the TTGO T-Call v1.4, that uses the SIM800H module for a cellular connection. It sends a custom notification message when a pin is pulled down, it can easily be expanded to send diffrent massages depedant on what pin is pulled down.
It can be made to use a battery backup easily since the T-Call board suports li-ion and lipo batterys as backup.