Quantity   Component name
1 × Arduino Uno R3 used in Phase 1 as main microcontroller, connected to PC via USB (Firmata)
1 × MQ-2 Sensor used in Phase 1 as basic smoke detection
1 × Arduino Uno R4 WiFi used in Phase 1 as WiFi-enabled microcontroller for standalone operation
1 × MQ-135 Sensor used in Phase 1 as high-sensitivity sensor for smoke and harmful gases
1 × Buzzer commonly used in 2 phases for audible alarm
1 × LED (Red & Green) commonly used in 2 phases for visual indicator of smoke status
1 × Breadboard & Wires Electronic Components / Misc. Electronic Components
1 × 9V DC Adapter commonly used in 2 phases for power supply