“This instructable explains how to make a “wink-detector” from a modified AD8232 ECG (electrocardiogram) sensor, an LM324-N quad op-amp, an Arduino Uno R3, and a home-made head-band.
The detector has two outputs … one for when you wink your left-eye … and one for when you wink your right.
Normal blinks, which involve both eyes, are ignored.
Applications for this circuit include:
Few tools are required … just a soldering iron and a sharp knife.
The sensor modifications, which can be reversed, require that you:
cut two tracks
add two solder bridges/shorts
add a short wire link
The estimated cost of components is $15.00”