Editing Alcohol Sensor Based on Gas-Sensitive Resistive Materials (section)

==== Working Principle ====
The MQ-3 sensor operates based on changes in its internal resistance when exposed to alcohol vapor. As the alcohol concentration increases, the resistance of the sensing material decreases, resulting in a change in the output voltage.
This voltage is read by the Arduino through its analog-to-digital converter (ADC).
The ADC converts the analog signal into a digital value ranging from 0 to 1023.
In this project, the raw sensor value is scaled by dividing by 10 to obtain a simplified percentage-like value. Although this does not represent the exact alcohol concentration, it provides a convenient way to observe changes.
The system continuously monitors this value and compares it with a predefined threshold. When the measured value exceeds the threshold, the system enters an alarm state.
In the alarm state, the LED is turned on to provide a visual warning, and the buzzer is activated to produce an audible signal. When the value falls below the threshold, the system returns to the normal state.