Development of a Microcontroller Based Digital Breath Alcohol Threshold Limit Detector

摘要

In many countries of the world, a major course of vehicle accidents is attributed to driving under the influence of alcohol. Various solutions to this problem have been found by the use of different types of technology. The digital breath alcohol threshold limit detector presented in this work correlates the breath alcohol concentration (BrAC) to the blood alcohol concentration (BAC) and determines the amount of BrAC required for safe driving. This is achieved by using a stable and sensitive gas sensor to d etect the amount of alcohol, particularly ethanol, in the breath of the driver. The output of the sensor, in form of voltage, is processed by a microcontroller that warns the driver in both visual and audible forms if it is safe to drive or not. The electronic circuit including the sensor, buzzer, and liquid crystal display (LCD), was implemented. The sensor was calibrated using ethanol solutions in the range that includes legal limits allowed for driving. The program for the microcontroller was developed u sing MikroC development environment and hardware simulation was carried out with the aid of Proteus Design Suite version 8.0. The project achieves the objective of being a screening type device that is meant to detect the presence of alcohol beyond a threshold value and to give appropriate advice to the vehicle driver. The device may also be useful to regulatory agencies that monitor the amount of alcohol intake by drivers.