[OWilliamson]

Last year our team created a custom circuit using a Hall Efect sensor. We attached 2 magnets (opposite poles facing down) to our front shooter wheel, and then fastened the circuit just beneath the wheel. We attached a PWM cable to the circuit, and we were able to interface it into the sidecar through a Digital I/O pin.

It worked by switching back and forth from high to low every time the wheel would spin a magnet over the sensor. In our code we treated it just like a counter, and from that data we were able to get the rotational speed of our shooter wheels.

In hindsight it probably wasn't the most accurate sensor that could have been used in that application. But, for our purposes it worked extremely well and were able to keep most of our shots in a very tight group by using it.