Arduino for Nerf: Chronograph and Shot Counter

Instructions for making a Nerf chronograph are at https://www.instructables.com/id/Arduino-for-Nerf-Chronograph-and-Shot-Counter/

Parts created in Tinkercad:
Cap and Body: https://www.tinkercad.com/things/ab6GUGshLud
Barrel Adapter: https://www.tinkercad.com/things/aPm1mKJBe1n