I saw this on instructables and had to try it… Luckily there are plenty of Nerf guns in this house….

I had a sensor amplifier board on the bench from a motorcycle Dyno project so I figured I could just use it with an IR Led/Detector too.

It was designed for these VR  automotive speed sensors…

 

Theres even a smaller standalone amp instead of the shield. Ultimately I’d like to build it into a barrel extension…

pick one of these…

add a 3D printed muzzle break….

and it works great….

and even the serial logging. Time to make that bluetooth to a custom Android app….

 

Nerf Chronograph