Build video: https://www.youtube.com/watch?v=y6WMAieY9Pc
Intervalometer based on an Arduino Nano, and set up with a series of 4 DIP switches. Arduino code available, as well as STL file for 3D printing base.
Works well for shorter time-lapses. After an extended test on 8-10-2018, after switching from 5 second mode to 30 second mode without a reset, it eventually started firing quickly after working properly for some time. Not sure of the issue here, may need to test further.