[FTC]: Spin Motor Wind Down: Programming

[l0jec]

Originally Posted by clwilligham

we tried that. the motors did some very odd things. the motors pretty much went haywire when we did this.

but we don't really want to turn off the brakes for all the motors. is there a way to set just 2 motors to float like in NXTG?

Your experience seems to match ours. One of my students came up with a possible fix (*hack*) which appeared to prevent their drive motors from flipping out when they wanted to coast their shooter motors. I'll check with him to see what it was and if it is a viable workaround; if it is, we'll post it.

[clwilligham]

thanks. that would help a lot.

in the mean time something like this might help for anyone else trying to keep there motors alive:

int motorSpeed = 100;


void powerDown()
{
  if(time10[T1] > 10 && motorSpeed > 10)
  {
    time10[T1] = 0;
    motorSpeed --;
  }
  else
  {
    motorSpeed = 0;
  }
  motor[shooter] = motorSpeed;
}

i haven't tested this either, but it is pretty simple and based off of previous functions from last year which worked consistently.

[l0jec]

Originally Posted by clwilligham

thanks. that would help a lot.

I talked with the student who had come up with a potential workaround. It sounds like he was adjusting the bFloatDuringInactiveMotorPWM before setting any motor speed. The reported observation was that the bFloatDuringInactiveMotorPWM was only read/applied when setting the power to a motor, not after. So if you wanted to only coast a single motor, you had to set bFloatDuringInactiveMotorPWM to true just before setting the power on that specific motor and then set it back to false before updating any other motors. Any other motors with power already set when the flag is changed do not get affected.
The biggest challenge I see with this type of workaround (assuming it works at all) is if you are setting motor outputs from different tasks.

I did not test this myself, but wanted to pass it along as promised.