This project is for a model railroad IR detector, used to sense when a part of a train is at a specific point along the track. It uses a before/after check to determine whether or not there is a reflection with some immunity from ambient lighting or external IR sources.
It started as an AT-Tiny project loosely based on Rob Paisley's designs and dustinandrews' instructable It evolved from a discrete logic circuit into an AT-Tiny one into a quad detector based on an Arduino core for ease of programming and economy of scale - one '328 is cheaper than 4x tiny's or the original (somewhat expensive) remote control TV detectors.
Use the provided code with board designs 2.1 and 2.2 - it will not work on the AT-Tiny versions!
