Programming Victor 884 control

[drakesword]

i have been batting this around for a few days but we cant seem to get our program to make the victors to move the motor.

we have everything plugged up and the cables in the right way.

we use:

pwm03 = (unsigned char)127;

and the motor doesnt move which is good.
light on the victor stays solid orange which is also good.

we use:

pwm03 = (unsigned char)140;

and the motor turns one way at a fair speed;
light turns off . . . good

we use:

pwm03 = (unsigned char)110;

and the motor starts to "tick"
the light flashes rapidly(faster then when it doesn't have a signal and in sync with the "ticks")
one of our mentors thinks that for one reason or another the signal is pulsing too slowly and is causing the jitter.

i have also determined that sometimes when we change the value too largely it will also "tick"(ex from 127 to 200)

as far as i understand(i could be wrong) the victor takes the PWM and a signal between 1 and 254

i have also tried using unsigned int instead and have gotten the same exact result

i have no clue whats going on(mostly because I'm a rookie) so if anyone could provide info it would be very very helpful

[Matt Krass]

You don't need the typecasts, simply setting the pwm to a value will work.
Such as:

pwm03 = 110;

Ticking sounds like not enough power, and 110 is pretty close to the neutral zone. I'd try a lower number, changing speeds rapidly is more of a problem for drivetrains than code. Try using a number like 63, that should be half power reverse, or close to it.

[Mike Betts]

Drake,

The ticking sound you hear is the auto resetting circuit breaker tripping over and over again.

Your problem is mechanical. A chain, (gear, et cetera) is binding in reverse.

You should see the Victor led turn off every time the CB trips in this condition. Hence the synchronous flashing you describe.

Proof: Remove the motor from it's mechanical house of bondage and it will operate just fine with the same code and electronics.

Mike

[drakesword]

that would make sence except that the motor isnt attached to anything

i will try not typecasting it when i get my battery recharged

[Jared Russell]

If it isn't the circuit breaker, it may just be innoculously flip-flopping between two values (one within the deadband and one within the negative motion range) - no big deal. PWM signals are somewhat inexact. See if you get the same results with, say, a value of 100.

[devicenull]

Originally Posted by drakesword

that would make sence except that the motor isnt attached to anything

i will try not typecasting it when i get my battery recharged

Then it's either a defective speed controller or defective motor.. Try a lower value though. If you want proof, get a decent multimeter (Depending on the motor, it could be drawing 40+amps at 12v) and mesasure the voltage coming off the speed controller.

[Al Skierkiewicz]

After you have tried everything else and are sure that the circuit breaker isn't tripping, (It produces a distinctive buzz and gets very warm>) then calibrate the speed contoller. It sounds like you might be on the hairy edge of being in the dead band (127 +/- 10). This is likely true if your joystick or pot input is sitting on the same table as the motor.

[Chriszuma]

It sounds like you need some good old fashioned debugging, since one part is obviously not working right.
1. Try different values for your pwm output (i.e. hook it up to a joystick input). If it works for different values, try calibrating the victor
2. Try running the victor without a motor attached, if it works the motor is screwy
3. Try a different victor, if it works then the first victor is screwy
4. Try it on a different pwm output, if it works you either have a logic error or a broken RC.

You don't necessarily need to do them in that order, typically start with the easiest one to test. That would be disconnecting the motor.

[Idaman323]

Where are you putting this code? I am trying to figure out why you need this. or where you need this. I am still tryign grasp all of the aspects of the code since I only had about 2 weeks to look at it last year.

Thanks

[zachriggle]

110 is probably in the neutral range. You will have to go a bit lower for anything to happen with the motor.

[drakesword]

Originally Posted by Chriszuma

It sounds like you need some good old fashioned debugging, since one part is obviously not working right.
1. Try different values for your pwm output (i.e. hook it up to a joystick input). If it works for different values, try calibrating the victor
2. Try running the victor without a motor attached, if it works the motor is screwy
3. Try a different victor, if it works then the first victor is screwy
4. Try it on a different pwm output, if it works you either have a logic error or a broken RC.

You don't necessarily need to do them in that order, typically start with the easiest one to test. That would be disconnecting the motor.

thanks chris it turned out it was the motor. one of the brushes is loose and whne the motor runs in one direction it looses connection thanks alot