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windell747
03-23-2010, 08:54 AM
Hi,

Is is permitted to have additional LEDs on the robot? If so, which set of outputs are we allowed to use? We switch our robots front and back assignments by inverting our controls and we would like to use the LEDs to indicate which is the front/back.


Thanks,
windell

tim-tim
03-23-2010, 09:20 AM
They are legal on the robot, as long as it does not affect the outcome or gameplay of the other teams. Mainly, is it too distracting for others, and will it affect the camera systems are the main two questions you should think about.

I am not sure what the proper way is, but we recently added some similar lights to an old bot at the shop to do some driver testing with a modified HUD. We simply ran them from a 20Amp Breaker to a Spike Relay. Then tied it to the cRIO with a PWM. I know this is the method for custom circuits that are non-functional*, but I would assume the same would apply functional lights.

Someone please correct me if I am wrong.

-Tim

*By non-functional, I mean decoration only

apalrd
03-23-2010, 09:21 AM
There are no rules directly against this, as long as it dosen't interfere with anyone's vision system, or is powered by something other than a 20-amp breaker (directly or indirectly). You can use DIO pins, Relay ports (they're actually 2 digital outputs), or Spikes to drive the lights. We use a few 12v automotive light bars (around 12" long) to indicate important things, and drive them with Spikes. You need 1 spike for 2 channels, although low-amperage lights can be ganged up on a single channel. You would probably have one channel for front and another for rear.

robself705
03-23-2010, 01:56 PM
We have them on ours (red LED underglow) and we had no problems passing inspection.

jblay
03-23-2010, 02:53 PM
Last year at UTC, team 230 had the most massive lights and they passed inspection. They were like neon lights. Lets just say I was happy not to be in a match with them.

Jeff Pahl
03-23-2010, 10:22 PM
As others have said, yes, they are legal as long as they are not going to interfere with other robots vision systems. This year that's less of a concern since the vision recognition targets are not lighted, or green.

The best way to do what you want to do is to connect the additional leds to spike relays so that you can turn on the ones you want in a given configuration. The important thing to remember is that if you are building your own led strings that they will be powered by 12 volts when you are doing your current limiting resistor calculation.