[Donut]

Something we're considering as an alternative... paint part of the wheel of your launcher and use an optical sensor to detect the change in color/reflection. It will not be as accurate as an encoder, but in theory it is the same thing, and requires no gear to read.

One thing to note on the gear tooth sensors, they will be generating an interrupt for every tooth, so it would not be wise to mount them on a many toothed gear on the actual shaft of the wheel. If you guess that the shooter is going ~2000 RPM, you have ~33RPS, and if you had a 49 tooth gear (like the ones that the gear tooth sensors are reading in the default transmission setup), you would be getting 1617 interrupts per second. Kevin and teams have had problems using the gear tooth sensors because of the massive amount of interrupts generated and because of the way the new processor saves data, resulting in some very weird program crashes. I don't know the current state of how things are going or why this problem is occuring, but keep in mind large amounts of interrupts could be an issue, especially if you still have interrupts being generated by other sensors.