LCD displays "FIRE HIGH" or "SMOKE HIGH". GSM module sends an SMS alert to emergency contacts. System resets when no fire/smoke is detected. Code File 📂 Filename: fire_alarm_system.ino 📌 Language: ...

At the heart of this ultra simple smoke alarm is H21A1, which is a photo-interrupter module consists of a gallium-arsenide infrared LED coupled to a silicon phototransistor in a plastic housing. The ...