[EricH]

Originally Posted by chuckmerja

Yes, ive tried this, but im not using a rangefinder, im using the IR Seeker from Hitechnic, for this years ftc game, it only gives me a number 1-9 and i know that those are the numbers for which section of its 240 degree range the seeker senses IR light.

You may want to try doing that test with an IR source aiming at a known section (the same section--let's just say section 1) from various differences. You'll probably want an oscilloscope to look at the signal itself, instead of just an output number.

If you're right, you'll see the signal change (get stronger) as you move closer with the IR source. If not, then you may want to find some other way of measuring distance.