tutorials
DIY Portable Breathalyzer & Ethanol Gas Tester with MQ-3 & OLED Display
Build a pocket-sized digital breathalyzer with an MQ-3 alcohol sensor and OLED display that gauges Blood Alcohol Content (BAC) estimates.
Kunal (Founder & Owner) 1 min read2 Oct 2026
DIY Portable Breathalyzer & Ethanol Gas Tester with MQ-3 & OLED Display
The MQ-3 gas sensor features high sensitivity to ethanol vapor with low cross-sensitivity to gasoline or cigarette smoke. Coupled with an Arduino Nano and an SSD1306 OLED, it provides instant visual feedback with color-coded safety tiers.
1. Operating Calibration
The MQ-3 heating filament requires a 24-hour initial burn-in to stabilize its chemical baseline. In clear air, the baseline ADC value sits between 100–180; exposure to alcohol vapors causes resistance to drop, spiking readings to 600–900.
Parts used in this tutorial
Buy them in one click — ships from Pune across India.
- Arduino NanoMicrocontrollers₹235.23+ GST
- MQ-3 Alcohol/Ethanol SensorSensors₹106.23+ GST
- 0.96 Inch Blue SPI OLED Display Module 7-Pin 128×64 – SSD1306Display & Communication₹99.00+ GST
Approx. total ₹440.46 (before GST)Add all to cart
#health#sensors#arduino
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