I'm a bit of a sucker for retro electronic novelties, and one of the most prolific is the "love tester" device that--in various forms--hearkens back to the early 20th century and the heyday of the penny arcade. These were often an electromechanical device that used some algorithm (or even just a random number generator) to ring bells, flash lights, and indicate either a fortune or--more often--a rating of one's romantic prowess. In the 1960s, Nintendo released their first (in what would prove to be quite a long line) of electronic toys which gave a love rating based on the electrodermal activity between two people. In this video, part of a series building a project for element14 Presents, I'll walk through using an Arduino to replicate the Nintendo Love Tester so you can build your own meter for your Valentine.