An improved Arduino-controlled photogate

Since the development of our Arduino-controlled photogate in 2012, we and other physics educators have used it with excellent results in both high school and college settings. At the same time, the feedback received during the manufacturing process, during the teaching of how the photogate works, and during the actual data collection and analysis, has brought us some very valuable pedagogical insights and has allowed us to improve upon our original photogate housing design and Arduino code. The goal of this follow-up article is to disseminate these observations.