Low-Cost Breathalyser Ignition Interlock

Driving under the Influence (DUI) is the act of driving a motor vehicle with blood levels of alcohol (BAC) in excess of a legal limit and is one of major risk factors for road traffic accident causing an average of 120, 000 accidents annually in Malaysia. There hasn‟t been any substantial device or system in Malaysia that is designed to monitor and prevent driving under the influence of alcohol (DUI) and methods to curb the offenders from driving while intoxicated are still limited. The author‟s proposed solution to this problem is a breathalyser ignition interlock device, an electronic device installed to a vehicle‟s ignition system used to measure and test the blood alcohol content in a person‟s blood stream before allowing for a vehicle‟s ignition system to be started up. This project involves the design, development and fabrication of a breathalyser ignition interlock device which controls an ignition switch. Upon assembly, the system is able to detect the alcohol concentration in a person‟s breath sample and displays the detected amount in terms of BAC (Blood Alcohol Concentration) percentage. According to the amount, the system decides whether to enable or disable the ignition switch circuitry which is pre-set to the legal limit of 0.08 g/dl in Malaysia for this project. We will limit the scope of this project by building an electronic circuit which will simulate a vehicle‟s ignition system instead of actually installing the breathalyser ignition interlock to a vehicle‟s actual ignition system due to time and financial constraints. The hardware module includes microcontroller board Arduino Uno, MQ3 alcohol sensor, LCD panel and ignition switch circuitry. The software component includes the programming and source code which is implemented via the microcontroller. Prototyping is selected as the methodology to develop the prototype. The main factor is because an electronic prototype device is hard to visualize before fabrication thus allowing for an incremental viewing, testing and observing the progress of the project which also allows for testing of each module of the individual function of the device thus ensuring that it is working as intended. The major findings from these project are the adverse effect of alcohol on driving capabilities, the risk factor of Driving under Influence (DUI), brief history on breathalyser and breathalyser ignition interlock and its effectiveness and finally key anti-cheat and anti-tampering features and functionalities in modern breathalyser ignition interlock