Circuit Description: LM358 Comparator: The LM358 operational amplifier is configured as a comparator. It compares the voltage from the gas sensor module with a reference voltage. Gas Sensor Module: The gas sensor module, specifically designed for alcohol detection (MQ series or similar), produces a variable voltage output based on the concentration of alcohol vapor. Potentiometer: The potentiometer is used to set the reference voltage for the LM358 comparator. It determines the threshold level for detecting the presence of alcohol. Resistor (R1): R1 is connected between the positive voltage rail and the output of the gas sensor module. It is used for biasing and limiting current. LED and Buzzer (Optional): An LED and/or a buzzer can be connected to the output of the LM358 comparator for visual and audible indications when alcohol vapor is detected.
