Hello,
I am working on a system that lets us go to an IR beacon, we already have movement down but I am having trouble trying to figure out how to read the ir beacon signal strength. I want to use the signal strength so we can figure out how close we are to the beacon. Any help would be appreciated.

I am not sure you can reliably use the signal strength to tell how close you are. The signal strength has a lot of variables such as the battery strength of the IR beacon, the amount of IR interference in the room. You are better off using other sensors to determine how close such as the sonar sensor. Even with two IR seekers, you can do triangulation with them.

We downloaded the latest RobotC Driver Suite and that solved our problem. We are using the signal strength for telling the robot when it is close enough to end it's autonomous stage.

We were thinking we could have a config mode where we hold the robot in front of the sensor and get the reading at a certain distance from the sensor so we can be able to judge distance without having to manually update the code based on the signal strength that can be different due to batteries.

You could compensate for the battery level if you code it that way. It is possible to read the immediate and average battery levels using intrinsic variables.

Don't ask me how it would work, though I am also not sure if would be necessary since most HiTechnic sensors work internally at a 3V3 level, so they may step down the 4V5-4V8, which would pretty much eliminate the dips you'd see with an analogue sensor.

- Xander

No, that's not the NXT battery you would worry about. It's the 9V battery in the IR beacon. If that battery is weak, the IR signal it generated will be weak. There is no way for the robot to know whether a weak IR signal is because it's too far away or if the beacon battery is weak without calibration.

I am pretty sure those beacons use a voltage regulator of some kind. Running 9V through one of those IR LEDs is sure to kill it quickly

- Xander

We just decided to make a calibration program that we run with the robot right where we want it to stop and then whenever autonomous is run it reads that the calibrated value and stops there. We are unsure if we will be able to do this during the competition but at least we have a quick way to adjust things when we get on the real field.