DIY Open Source Chronograph
I got into airsoft recently, and I wanted a way to measure the BB’s velocity. The cheapest chronographs I could find were ~60-70€. I thought making one myself would be much cheaper and a good learning experience. The total cost was about 15€. I tested it with an Army Armament R504, its specs sheet says it shoots at 300 FPS, I measured 298 FPS which is within the margin of error. All the files for the project can be found on github. Schematic Below you will find 2 versions of the schematic. One using photodiodes and the other phototransistors. Initially…