Upgraded Mosquito Swatter Tracks Your Score

Imu34 lives in an area where from spring to autumn they’re plagued by the tiger mosquito. While local stores offer a wide variety of elimination devices, his weapon of choice is the cheap and simple electric swatter. These devices work by using an oscillating circuit to produce hundreds of volts of electricity through the conductive racket mesh.

Simply eliminating these bugs, however, wasn’t enough for Imu34, and he decided to upgrade his swatter with video game-style audio clips and an automatic score counter. The modified swatter runs on an ATtiny167-based Digispark Pro board and employs a four-digit seven-segment display to tally up mosquito kills. An MP3 playback module produces sound via a newly added speaker, and a rechargeable battery keeps mosquito pummeling fun going all spring-summer-autumn long.

To keep track of the score, the onboard ATtiny measures the current consumption by monitoring voltage changes across a resistor between the battery and swatter circuitry. This signal is course a bit noisy, but by calculating the standard deviation, as elaborated upon a bit further here, it’s able to pick out kills – and even the occasional “monster kill”–among swipes. The setup utilizes a 470uF capacitor for noise filtering and to surge enough power when needed.

While this upgraded mosquito swatter might not make getting poked by these little beasties any less annoying, at least now Imu34 can keep track of how many of them he’s taken revenge upon. He'll also be cheered on with the sweet “m-m-m-monster kill” sound upon success.

Code, print files, and even sound clips are found in the project write-up if you want to make one yourself!