Optimizing Speed Controllers

[flameout]

Originally Posted by 4DFudge

So, my team is trying to use the inputs on the speed controllers (and possibly the sidecars) more effectively, to improve our overall robot. One of mentors brought up using CAN bus however I'm not exactly sure how I would go about setting this up(if this is actually more efficient than the connection of every jag being connected to a different input on the digital sidecar). So I was just wondering if other teams had used other inputs that improved their robot's preformance.

Also I have read the datasheet for the digital sidecar and it seems as though the connections are pretty clear cut but I just wanted to make sure there aren't more creative uses.

Thanks

We did some testing last year (using Java), and determined that CAN is in fact slower than PWM (in terms of update rate). Therefore, unless you are using the built-in closed-loop control features (control of current, velocity, and position as well as exact voltage are possible), I do not see any competitive advantage to CAN

However, PWM cables are known to be a bit unreliable, so CAN is an improvement in reliability.

There's a guide (or two) on the forums for setting it up. I suggest looking in the "CAN" subforum.

Fyi, we found last year that Java's CAN driver averages 180-200 commands per second (depending on the command). The Jaguar's PWM is updated at 200 Hz, and the Victor's is at 100 Hz. The internal PID algorithm in the Jaguar runs at 1000 Hz -- so if you need closed-loop control, then CAN might be a better option for some of your Jaguars.

Good luck with whatever you choose to go with.