Whats the Robot Signal light for?

What does it do? The red/black from PWM pull in the relay. Does the PWM just sit at 127 and turn on the light? WE tried it and the light didn’t go on. I’m not sure the relay pulled in. It looks like there’s red indicator light on the relay, but it never lit. Any help or ideas? I didn’ see anything in the rules about it.

The light is what they call the “Safety Light” and is supposed to function as a signal light, warning flasher, and robot status indicator light. At least this is what it FIRST says in their papers. As for actual practicality, I haven’t looked into that yet.

<R16> ROBOTS must use the diagnostic signal LED provided in the Kit Of Parts. Field personnel
will use the LED during the matches for diagnostic purposes. It must be mounted on the
ROBOT such that it is easily visible while standing three feet in front of the ROBOT in its’
STARTING CONFIGURATION. Instructions for connecting the LED are provided on the
FIRST website at www.usfirst.org/frc/2007/manual The Robot Controller directly powers
and controls the LED. The user has no control over the LED and no programming is


The way I have interpreted the signal LED is that it is in some ways a replacement for the diagnostics side of the old LEDs.

The color aspect of the old LED has been completely overtaken by the flags and the diagnostic aspect is going to be taken by this new LED.

Did you plug it into the Team Color outputs (black on black with one pin left unused) or a PWM output?

We have the signal light all wired up, but I dont know where it plugs in. Is there any programming needed?

Perhaps since it’s a relay, it plugs into “relay” where a spike relay would normally go?

No programming is required at all.
It plugs into the same outputs as last year’s LED. Any one of the four “Team Light” outputs can be used.
The new LED is wired to only use the first 3-pins of the 5-pin outputs, starting with Black-on-Black. Leaving an extra two pins exposed and unused.

It’s spelled out in the last two sentences on page 38 of the “FIRST 2007 Guidelines, Tips, & Good Practices” document found at http://www2.usfirst.org/2007comp/other/2007%20Guidelines_Tips_Good%20Practices_RevA.pdf

Ah, now I see in the Tips amd pratices. We plugged it into a pWM, not the team colors. I won’t be trying it tonight, but what does it do? Does it do something under controlof the judges?

The signal lights are used by the IFI staff to determine what is going on with your control system if there is a failure on the field. It helps them determine if there are programming issues, battery issues, etc while the match is running. YOU WANT THIS LIGHT FUNCTIONING. I helped with the IFI field controls last year in toronto, and in addition to their radio diagnostic tools, this light is immensely helpful in quickly determining if there is a field issue (99% of the time its actually not the field!!).

What are the patterns on the light supposed to be as the bot goes from enabled to disabled?

(Sorry if this is a silly question. Rookie team.)

This is from memory, so don’t take it as authoritative. If you’re tethered, I think it blinks no matter what. If you’re connected by radio on channel 40, it blinks when enabled and is on steady when disabled. If you’re on channel 31, it stays off.

A team color LED assembly from last year tells more of the story. Different channels blink either red or blue; tethering alternates both. This year’s amber signal light comes on when the old light would be red.

Thats correct. The only thing that disappoints me about this new light is that the Autonomous and Human Operated modes both have the same flash pattern, as opposed to the previous hyper-flash for Autonomous and the slower flash for Human Operated.