[Foster]

I responded to Colby in a PM on how to get overnight shipping.

As far as many IR sensors go, it is possible to put a large number of sensors on the robot. You are limited by two things:

1) Number of analog ports available. These are very simple voltage devices (the closer the object is, the more light is reflected, the more light they see the higher the voltage) so it's not a load on the system.

2) Reflections from other IR sources. The beam from the IR LED that is illuminating the target is fairly narrow. But due to bounce patterns that light may be seen by another sensor. You can use this to your advantage by using the sin/cos formulas to triangulate the position. You can also narrow the focus by putting the sensor in a tube. (EricH's example)

It takes some experimenting, but it's pretty fast to make changes and figure it out. And since the hold back allowance has gone up 20 lbs it shouldn't be a problem keeping a few of the 1oz sensors to play with.

Good luck!