I would like to put up four sensors at 0,10,20,40 to track a 40yd sprint. There will only be one running at a time.
But with this distance, I was wondering if there is some sort of wireless solution at each split that would be accurate enough.
Any ideas to get me started?
Probably the “right way” is, at each sensor point, have a microcontroller with a photo gate and a RF transmitter. Then have a microcontroller with the matching RF receiver to capture the signals from the microcontrollers at each sensor point. SParkfun sells radio for this https://www.sparkfun.com/search/results?term=rf.
For the photo gate you would have an IR detector on each microcontroller pointed at a battery-powered IR source on the other side of the track. When the runner gets between the light source and the detector you the microcontroller transmits the right signal. It would basically be a larger version of the photo gate sparkfun sells (https://www.sparkfun.com/products/12876).