Is the suggested Vision Camera setup ILLEGAL?!

[Dave Flowerday]

Originally Posted by RIgnazio

You CAN NOT use the camera servo outputs to power the angling servos for the camera.

Yes you can. There have been several threads on this subject already, and it has been asked and answered on the FIRST Q&A.

{edit} Looks like someone merged this with the other thread that was already talking about this subject after I posted this. {/edit}

ID: 1183 Section: 5.3 Status: Answered Date Answered: 1/17/2005
Q: May we connect servos to the PWM outputs on the CMUcam to take advantage of the automatic pan and tilt control that it provides
A: Yes. Servos connected to the camera module are considered part of the camera module and can only be connected to it.

[Steve W]

I have merged these 2 threads to make 1 of the same.

[RIgnazio]

Pretty much, FIRST has made it confusing, once again. according to <R53>:

<R53> Custom Circuits may not:
• Interfere with the operation of other robots
• Directly affect any output devices on the robot, such as by providing power directly to a motor, supplying a PWM signal to a speed controller or supplying a control signal to a relay module. (Custom high impedance voltage monitoring or low impedance current monitoring circuitry connected to the robot’s electrical system is acceptable, because the effect on the robot outputs should be inconsequential.)
• Be used for wireless communication, such as sending or receiving a signal to and/or from the alliance station
• Connect to the radio or tether ports on the Robot Controller

it states that it can not control an output ON THE ROBOT.
Obviously, the camera is going to be on the robot, and not hovering or anything. (If you can get your cam to hover, let me know how! j/p)

Now, according to the Q&A

ID: 1183 Section: 5.3 Status: Answered Date Answered: 1/17/2005
Q: May we connect servos to the PWM outputs on the CMUcam to take advantage of the automatic pan and tilt control that it provides
A: Yes. Servos connected to the camera module are considered part of the camera module and can only be connected to it.

it is quite alright. I think someone needs to e-mail FIRST. I personally believe the rulebook, and am surprised that it hasnt been included in the latest FIRST rules update.

[dlavery]

Originally Posted by RIgnazio

Pretty much, FIRST has made it confusing, once again. according to <R53>:

it states that it can not control an output ON THE ROBOT.
Obviously, the camera is going to be on the robot, and not hovering or anything. (If you can get your cam to hover, let me know how! j/p)

Now, according to the Q&A it is quite alright. I think someone needs to e-mail FIRST. I personally believe the rulebook, and am surprised that it hasnt been included in the latest FIRST rules update.

Actually, it seems quite clear. Rule <R53> has to do with custom circuits. Question 1183 makes it clear that FIRST considers the CMUcam II system - including the connected servos - to be all one module that is supplied in the kit. It is not a "custom circuit." Therefore, <R53> does not apply. Thus, connecting the servos to the camera, as detailed in the supplied documentation from FIRST, is legal, and <R53> and Q 1183 are perfectly consistent.

-dave

[Rickertsen2]

Originally Posted by dlavery

It is not a "custom circuit." Therefore, <R53> does not apply. Thus, connecting the servos to the camera, as detailed in the supplied documentation from FIRST, is legal, and <R53> and Q 1183 are perfectly consistent.

-dave

Ah but by that reasoning what prevents us from connecting the speed controllers to digital IO and using them to generate a PWM signal?

[Dave Flowerday]

Originally Posted by Rickertsen2

Ah but by that reasoning what prevents us from connecting the speed controllers to digital IO and using them to generate a PWM signal?

Probably the part of their answer to the Q&A that says "Servos connected to the camera module are considered part of the camera module and can only be connected to it." Let me rephrase what I think they said (just my interpretation, of course...):

"Only servos which are mechanically connected to the camera module are considered part of the camera module and may be driven by the servo outputs on the camera."

[Joe Ross]

Originally Posted by Rickertsen2

Ah but by that reasoning what prevents us from connecting the speed controllers to digital IO and using them to generate a PWM signal?

Is there a rule that prevents it? Isn't that basically what PWMs 13-16 are?

[Dave Flowerday]

Originally Posted by Joe Ross

Is there a rule that prevents it? Isn't that basically what PWMs 13-16 are?

Remember that PWMs 13-16 though can be shut off by the master processor (even if your code is trying to control them). There is nothing that allows the master processor to shut off the PWMs on the camera, hence hooking anything other than the camera pan and tilt to them would be a major safety concern at competition. When the field crew disables a robot, they need to be absolutely certain that that robot is not going to move and potentially hurt someone in the process.