Design and characterization of breath analysis system for BAC prediction

A breath analysis system was created using two sensors. The first was an alcohol gas sensor (Hanwei MQ-3) which provides an analog resistive output based on the ethanol concentration in an air sample. The second was a humidity sensor (Honeywell HIH-4030), to help verify that a proper breath sample was received. The sensors were integrated with an Atmega 328p based microcontroller on an Arduino Nano development board. The Arduino communicated with an Android application through a Bluetooth transceiver, allowing a user to measure his or her Blood Alcohol Content (BAC). The device was calibrated and evaluated using three commercial offthe-shelf breathalyzers.