Lie Detector with Arduino

I’ve invited some fellow writers for dinner and books went missing.

Instead of sending who-stole-the autobiography-of-Klaus-Kinski email. I’ve decided to make a Nano Lie Detector (AKA Polygraph) for next dinner.


A polygraph is a device that measures physiological indicators while a person answers a series of questions. Deceptive answers will produce certain physiological responses that can be differentiated, for example: increased heart rate and changes in sweat gland activity (galvanic response)

There is a cheap sensor to measure heart rate and with some easy to find parts, a galvanic response sensor can be made. Arduino will measure both sensors and presents the information using a vintage analog vu-meter. If galvanic response is high enough, a buzzer will provide an audio alert as well.


Analog Vumeter x2

Arduino Nano

Heart Rate sensor

Jumper cables

Aluminum foil



5V power source


Strange machines department

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store