CMU Cam servo jitter

[Mr. Lim]

Originally Posted by adamdb

When I hooked our CMUCam2 up to my PC for testing, both the pan and tilt servos "jittered" constantly. Kind of like they couldn't decide on what the exact center position was and were constantly switching between two positions.

I am using an external wall-wart type supply that supplies 12V and 500mah. The jumper for "use internal power to servos" is on.

Is anybody else experiencing this? In RC airplanes we will occasionally see jitter like this when using a fully charged 6.0v battery and it will continue until the voltage has dropped off a little, but I am assuming that power for the servos in this case is regulated to 5v, so it should not be an issue.

Thanks,
Adam

We saw this jitter too when we powered it directly from the 12V breakout on the robot, but realized quickly that you're not supposed to do that unless you switch the "Servo Power" jumper to "External" - and then power the servos directly from a 7.2V source.

Chances are you're giving your servos 12V of power, like we were, and it's probably not a good idea to keep doing that. They like 7.2V much better.

I would recommend powering your camera right from a PWM output of the robot controller. Just pick one that isn't going to be used, and steal the power leads from it =).

-SlimBoJones...