weird drive problems

[samknight213]

We have had this problem for about a week and a half, so when we drive forward its fine. When we turn left while driving forward, it's fine same as the right. When spinning left and right it is also fine. But the problem comes when we drive backwards. Driving backwards straight is fine, but when we turn left on the joystick the robot turns back right and vice versa. Does anybody have a clue what is happening in the code. We have tried making a case structure in teleOp.vi to see if the y axis is positive or negative then inverse it if it is negative but we may have done it wrong so if you could show a picture of how it should look. Thanks....

But who knows I've been blaming wiring because that's what I do when I don't know something.

[Kevin Sevcik]

You have your left and right sides mixed up. Swap your left and right motors in the code and you'll be fine.

Also, welcome to ChiefDelphi, and feel free to ask a little sooner than a week and a half of struggling. Maybe just a day or two?

[samknight213]

We have changed the PWM's to match the PWM's on the chassis but it still doesn't work. and thanks for the welcome.

[Kevin Sevcik]

Oh, I kind of skimmed your original post. Didn't realize the problem was only when you were backing up. I think the behavior you describe is actually the correct behavior for most usual "Arcade Drive" setups. Left-right on the joystick controls rotation direction and speed. Front-Back controls forwards-backwards motion. The behavior you describe just follows from there. If you're turning clockwise and moving forward (away from the driver), the robot turns to the driver's right. If you're turning clockwise and moving backward (towards the driver), the robot moves to the driver's left.

If you want different behavior, you'll have to program it yourself. It's tricky to get the robot to spin in place, turn the "same direction" moving forwards and backwards, and not destroy motors and gearboxes when you go from moving forwards to moving backwards.

[samknight213]

Do you use arcade or tank, (I don't think mecahnum is good for this challenge) and what does the team driver find easier to do?

[Ether]

Originally Posted by samknight213

mecahnum

http://youtu.be/LlSoEfAW47I?t=3m33s

[samknight213]

mecanum then, sorry