Re: IR Beacon/reciever not working... still...
 

make sure that the beacon is hucked up right. the code is looking for either beacon type 0 or 1. look in the code and find out.

Re: IR Beacon/reciever not working... still...
 

receiver's still not working.......since we only have one, we fixed the codes, but....still, none...

Re: IR Beacon/reciever not working... still...
 

are u sure that ur beacon is wired correctly. also check the wiring for the sensors.

Re: IR Beacon/reciever not working... still...
 

I just realized today, that the when the reciever goes low, it only goes low to 3.5 volts and when its high its ~4.9 volts. I think that it's not making the voltage dip low enough to have the controller register that something has changed. Can any other teams having problems (or have working recievers) verify this?

Re: IR Beacon/reciever not working... still...
 

Here's a few more things to try...

1. Make sure your beacon is on the right pwm output - we found that by default, the RC code looks for the beacon from edu-pwm-out 2, not 1
2. Again, make sure your left-left, left-right, right-left, and right-right receievers are on digital inputs 1, 2, 4, 5, respectivley - input 3 is not used.
3. Make sure your left and right servos are on the appropriate outputs (check the code you're using - there are several variations depending on if your running your tracking from the edu or the full rc)
4. **DEBUG YOUR BEACON/RECIEVER SETUP USING THE TRACKER.ZIP VERSION OF THE CODE**
4a. tracker.zip just makes the servos go back and forth until they find the beacon - there's no navigation or robot movement involved
4b. If you load the program on and your servos don't move...
4b1. Unplug the beacon. If the servos still don't move, you have a problem with your wiring. If the servos do move, they were successfully seeing the beacon or a reflection of the beacon. If the latter happened when you think it shouldn't have happened, refer to the various threads about the shotgun setup approach, ambient lighting, and Kevin's faq (http://www.kevin.org/frc)
4c. If your servos do move (even though you have your beacon in front of them)...
4c1. Check to make sure the beacon they're looking for is the beacon you're transmitting - if your beacon is on edu-pwm-1, move it to edu-pwm-2
4c2. Make sure all of the receivers are plugged in (sometimes the connectors fall out due to the servo's motion) and plugged in to the correct inputs (again, its 1, 2, 4, 5)
4c3. Make sure your beacon is working - I found this is best done by inserting a visible-wavelength LED with the appropriate resistor in parallel to the IR leds - when you move the beacon quickly from side to side, you should observe a strobe-light effect from this LED - this strobe effect means that power to the IR leds is being cycled according to the waveform the edu is generating
4c4. If those fail, you've got a wiring fault - check to make sure the correct PWM wires go to the correct pins on the receivers and the beacon. One way to debug this would be write a simple program that just printf's the value of the digital inputs and make the beacon output constant light instead of the pulsed waveform.

Again, the behavior of tracker.zip is it just makes each servo move back and forth until both of the servo's receivers find the beacon (or a reflection of it). For example, if you're holding the beacon right in front of the two servos and one servo is moving while the other is stopped, first unplug the beacon. If the stopped one starts moving, then you know there's nothing wrong with it and the problem must lie in the connections of the other one.

Also, I've said "unplug the beacon" several times because simply hiding it with your hands does not always work. Depending on the conditions of the room (ambient light, reflectivity of materials, etc.) and the quality of your 'shotgunning,' you could have conditions so bad that your receivers could be on one side of a box while the beacon is on the other and the receivers will still pick up a reflection of the beacon (trust me, it's happened to me). The best way to make sure your hiding the beacon is to unplug it.

Hope this helps everyone.

Re: IR Beacon/reciever not working... still...
 

If you don't put a switch on digital input 7 to select the type of beacon you want to track, it defaults to beacon type 1, which is present on PWM output 2 on the EDU-RC. Thanks for pointing this out. I'll add this to the FAQ.


This only applies to the code in navigate.zip. The version of receiver.c in tracker.zip uses 3, 4, 5, 6. The reason for this is in the FAQ.


Actually, we've always used PWM1 and PWM2.


Also make sure you have a 7.2 volt battery plugged into the battery connector. The servos won't work without it.

-Kevin

Re: IR Beacon/reciever not working... still...
 

er, I was thinking about the version which ran both the tracking and the beacon off of one edu that Marc McLeod put together a few threads ago... that one had the servos off of PWM7 and 8


Anyways, since there seem to be many people having problems with their IR beacons, I decided to make a flowchart to help them debug common problems that I expierienced while getting my team's setup to work. This flowchart is a lot clearer and more organized than my last two posts, so I hope this helps everyone out. If anyone sees any mistakes/things that have been left out, let me know.

[EDIT]
From the origional version I posted, I changed a few things, fixed a few careless typos, and added some wiring maps to a second page. Check it out.

Re: IR Beacon/reciever not working... still...
 

well that voltage drop does seem correct. that is pretty much what we get.

Re: IR Beacon/reciever not working... still...
 

We got our hands on some detectors. This time the voltage droped down to 30 mV instead of 3.5 V. The controller registered an interupt and we rejoiced.