Arduino Alcohol Detector Circuit Board

The Arduino Alcohol Detector Circuit Board functions by utilizing an MQ-3 alcohol gas sensor mounted on a custom PCB, interfaced with an Arduino microcontroller. The MQ-3 sensor contains a sensing element made of tin dioxide (SnO2) on a ceramic microtube, which has a lower electrical conductivity in clean air. When alcohol vapor comes into contact with the sensor's sensing surface, the gas undergoes catalytic combustion, which decreases the resistance of the material. This change in resistance alters the output voltage of the sensor circuit. The custom PCB neatly routes these analog voltage changes, alongside necessary pull-up or biasing resistors, from the sensor module to the analog input pins of the Arduino. Connecting wires ensure secure electrical pathways between the sensor, the passive resistors, the custom circuit board, and the microcontroller. The Arduino, programmed via the Arduino IDE, continuously reads this incoming analog voltage level. By processing the analog-to-digital converter (ADC) values, the system can determine the relative concentration of alcohol present in the surrounding environment, converting raw electrical signals into actionable measurement data.