Arduino + Jaguar Speed Controller + CIM Motor

[NickLD3753]

Hi, I think what your issue is might be with the default pulse-width of the signal coming from the Servo library.

Some manufactures decide to vary their input range from the standard timings. Also, most RC servos (what the Library was made for) have a different range from what I have seen FRC Controllers use most of the time.

I did a quick look for the Jaguar Datasheet and found this:
http://content.vexrobotics.com/docs/...t_20130220.pdf

This is what the Datasheet says about the input range:

Minimum pulse width 0.67 ms
Neutral pulse width 1.5 ms
Maximum pulse width 2.33 ms

All We need to do now is convert the ms to us:

Minimum pulse width 670 us
Neutral pulse width 1500 us
Maximum pulse width 2330 us


Now the great thing about the servo library is the ability to skip the scaling of the normal RC servo range and just input the raw us timing values.

myservo.writeMicroseconds(UsTiming);

After that It should be pretty easy to map the values accordingly.

I hope that solves your issue!

[Al Skierkiewicz]

Please don't forget that the CIM motor has a brush bias that is optimized for one direction over the other. While it is slight, there are production variances that may make individual motors respond differently. Other motors are known to have greater bias differences.

[Michael Hill]

Originally Posted by Al Skierkiewicz

Please don't forget that the CIM motor has a brush bias that is optimized for one direction over the other. While it is slight, there are production variances that may make individual motors respond differently. Other motors are known to have greater bias differences.

Could you tune this by loosening the bolts, and rotating the black section that houses the permanent magnets (Not saying this would/should be legal on an FRC robot, just technically possible). There are tick marks on each of the sections so you could potentially reliably clock the magnets in relation to the brushes.