Flask Breathalyzer

January 2017

 

I. Motivation

For Lunar New Year, a colleague in Taipei gifted me a limited edition bottle of 金門高粱酒, a.k.a. Taiwanese moonshine. I figured that building a breathalyzer would be a fun and practical way of quantifying its overproof alcohol content (63% ABV), and comparing it to beer, wine, and whiskey.

 

II. Inspiration

  1. Tucker Max's “Sushi Pants” story, and

  2. This classic video:

 
 
 

III. Materials

  • Arduino Pro Nano

  • MQ-3 alcohol sensor module

  • WS2812B RGB individually-addressable LED strip

  • Old Crow® Kentucky Bourbon (375ml plastic bottle)

  • Portable USB charger

  • Micro-USB breakout board

  • Micro-USB cable

  • Small breadboard

  • Jumper wires

 

IV. Circuit layout

[Insert image from Fritzing here]

 

V. Code

 
 
 

VI. Testing

 
 
 

VII. Next steps

The breathalyzer successfully correlated drinks with known alcohol content with x lights - beer and wine yielded 3 to 4 LEDs, while the Kaoliang liquor maxed out the LEDs on the light strip.

Changes to be implemented in future revisions:

  • Implement logarithmic mapping to accommodate a larger range of sensor readings

  • Install waterproof/breathable membrane over the sensor module to reduce sensor contamination

 

XIII. Acknowledgements

Special thanks to my friend and former colleague Timgo Chang for the bottle of 高粱酒!