Alcohol Detector and Engine Locking System Using Arduino Uno and MQ3 Sensor

The prevalence of alcohol-related traffic accidents has led to a growing demand for technological solutions that can prevent drunk driving. This paper presents a design and implementation of an alcohol detection and engine locking system using an MQ3 sensor and Arduino Uno. The system detects the driver’s blood alcohol concentration (BAC) through breath analysis using the MQ3 sensor, which is calibrated to detect ethanol levels effectively. When the sensor detects alcohol levels above a preset threshold, the Arduino microcontroller processes this data and initiates an automatic locking mechanism on the vehicle’s engine, thereby preventing its operation by an intoxicated driver. This design offers a real-time, cost-effective solution for personal vehicles and public transport applications, aiming to minimize road accidents due to drunk driving. The system’s hardware components are low-cost, compact, and can be easily integrated with vehicle electronics, making it suitable for widespread implementation. Furthermore, additional enhancements can be integrated, such as GSM modules for alerting emergency contacts or GPS tracking for location-based monitoring. Through this study, we aim to demonstrate that the proposed alcohol detection and engine locking system is a viable, affordable, and effective measure to enhance road safety and reduce drunk driving incidents.