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 https://amzn.to/2EPgXez
Arduino Nano https://amzn.to/3ih8mQw
Heart Rate sensor https://amzn.to/2Dq3Os0
5V power source