Robot Jumping on Power Up

[MikeDubreuil]

Originally Posted by Mike Betts

I have not changed this at all (even though I now realize that the Victors require a 132 for a true neutral, 127 still works)...

I did not realize that! Can you explain why 132 is neutral? Thanks.

[Mike Betts]

Originally Posted by MikeDubreuil

I did not realize that! Can you explain why 132 is neutral? Thanks.

Mike,

See the data at the beginning of this thread. I confirmed the data by experiment. The Victor has a zero output when given PWM values of 125 to 138 (mean 132).

A lot of the referenced thread goes into what might be causing the problem. I do not know why the Victors are non-linear. IFI claims that that they are linear (see this) but this assertion is not backed up by experiment.

I have attached my data, taken with this year's kit frame, gearbox, CIM motors and wheels using the kit Hall effect sensors counting sprocket teeth with the frame on blocks (free speed except for bearing and gear friction).

However, this is getting off topic...

Regards,

Mike

[eugenebrooks]

Originally Posted by Mike Betts

Since we upgraded our RC to the V10 Master Code, we have noticed a problem with all PWM's jumping to full on (254) for a fraction of a second after power up.
Mike

We did not see this problem when we upgraded to V10 at the Sac regional.

If you are not using the custom pwm outputs, and have the default call that sets them up at the end of the main loop, try commenting this code out. We have had strange behavior, in the past, when this call was left in and taking it out is standard procedure at this point.

Another thing for you to check is that you are running the patch that was published by IFI late in the build period last year. Without it, you can get bad effects upon startup. If you started with this year's default code, you would have this patch.

If you resolve the problem, please post the resolution.

[Jack Jones]

Originally Posted by Mike Betts

Since we upgraded our RC to the V10 Master Code, we have noticed a problem with all PWM's jumping to full on (254) for a fraction of a second after power up.

This problem does not appear with a robot reset while power is on... Just once every power up.

Is anyone else seeing this or, even better, figured out what causes it?

If we are the only ones, we may have a defective controller...

Regards,

Mike

We had a similar problem. Fix was to calibrate Victors.

[Mike Betts]

Originally Posted by Jack Jones

We had a similar problem. Fix was to calibrate Victors.

Jack,

This is seen with a servo attached to any PWM output. It is not a Victor problem...

Regards,

Mike