« Reply #5 on: February 03, 2011, 02:14:46 am »
Will need to make it sturdy to protect against errant pitches.
60 MPH, that's 88 feet per second, 1056 inches per second.
Baseball is about 3 inch diameter, will be thru your frame in about 2mS.
You will need a 18" x 18" opening to simulate the strike zone.
Sensors at least every 2" I would guess so at least a portion of the ball is always picked up.
So 8 sensors (2", 4", 6", 8", 10", 12", 14", 16") in vertical & horizontal, 16 total, scanned rapidly enough so that every intersection is read within 2mS. So reading at 125 uS clip?
You can make a loop that can go that fast no problem.
Not sure if having 2 interrupts occur, then you scan the inputs to see which 2 detectors got momentarily blocked, will do it.
May need to have the detectors trigger a flip-flop or similar to capture the transition, scan them after any one is triggered, similar to the keypad tutorial.
Don't know if IR will do it for you, you'll have look at the radiating spread angle of your sending device and see if it will be picked up by the neighboring detectors.