Master module

The master module consists of a magnetic reed sensor, a push button, a buzzer and an ESP32 module. The ESP32 module is the master module of a BLE network and is read to receive signal from the slave modules. Whenever a slave module sends a signal, the master module fires the buzzer if the system's state is in ARM mode (ARM mode is the mode where all residents are away from the residence and the last to leave arms the alarm by pushing the push button). By the time a user arms the alarm, a timer is triggered, so that any door change state doesn't fire the alarm by accident and the user has got time to leave the residence. When a user return to the residence he has got 20 seconds to Disarm the alarm by pressing the push button so that the buzzer doesn't ring after the 20 second interval.