I would like to use a photo cell and light source 14" apart to detect nbn balls entering the robots intake.
I tried a 276-2158 photo sensor and a 276-2210 flashlight. It works with an incandescent light source, but not the VEX “LED” legal flashlight. I tried using (2) 276-2154 line trackers, one for the emitter and one as the receiver, but the 14’" distance was probably beyond their range.
What has worked for detecting nbn balls?
Use limit switches.
You also could use ultra sonic sensors to determine if it had been intaked.
As there is a 14" gap, I am guessing you want to detect when a ball is near to automatically start the intake, or something similar. Limit switches would be best for an area where you know exactly where the ball will be when you need to sense it (i.e. along a straight path), but for this an ultrasonic sensor would be the best option.
You can also use an individual line tracker to detect when a ball is present, but this too would need to be close the ball and almost touching it to work best. At 14" it will not work.
You could put a bunch of line trackers on top of the intake to detect from the top. You do have 8 analog ports, after all…