Re: IR sensor or Magnet sensor
For IR sensor reliability, please refer to the following thread.viewtopic.php?f=52&t=2780&hilit=accuracy
I have not done much with the magnet sensor. However, I did experiment with it for the FTC game this year and found that if the magnet is inside the racquet ball and resting on the bottom of the ball, then the magnet sensor may not pick up anything from the side of the ball. If you put the magnet sensor where the magnet is, then it is pretty accurate.