This project refers to an Arduino sketch that implements the logic of a digital indicator of alcohol content. This system can be used as a device for breath test. There is the MQ-3 sensor in the system to detect alcohol. A suitable multi-LED bar graph (which is driven by a 8-bit shift register 74HC595) is used as an indicator rating the alcohol content. If the alcohol content is high, then a tune is produced through a suitable piezo speaker. Finally, there are two buttons in the system for functions such as ON, OFF and a LED which is the operation indicator.

Below there are some pictures of the project:

For more information you can get the project itself: