One Joystick Drive

[mattsavela]

http://photobucket.com/albums/v660/lhsrobotics/
http://photobucket.com/albums/y205/lhsrobotics1/


Those are the two links to our photo albums.

[N7UJJ]

I assume you are going to the MATE championship in Houston.
If so be sure to look for us. We also use the FRIST controller equipment on our ROV except we put the robot controller and the battery on the ROV. It allows us to use a small diameter tether which really helps the maneuverability.

Looking forward to meeting y'all

Allan

[mattsavela]

Yeah. We are going to the MATE competition in Houston. Our team saw some pictures of your team's robot (not sure what year), but it was in one of your past tech reports. It looked excellent.

[mattsavela]

We finally got a chance to test our robot in the pool. The robot worked fine going forwards, and turning. However, when we pull our joystick backwards, the robot goes forward, and when we push the joystick forward, our robot goes backwards. Is there a way you guys can help me fix that? Also, our robot does not goes very fast when it is moving backwards, but moves at a good speed when it goes forwards. Is there a way to make it so that when we go backwards, it goes the same speed as it goes when going forwards?

Thanks

[N7UJJ]

Originally Posted by mattsavela

We finally got a chance to test our robot in the pool. The robot worked fine going forwards, and turning. However, when we pull our joystick backwards, the robot goes forward, and when we push the joystick forward, our robot goes backwards. Is there a way you guys can help me fix that? Also, our robot does not goes very fast when it is moving backwards, but moves at a good speed when it goes forwards. Is there a way to make it so that when we go backwards, it goes the same speed as it goes when going forwards?

Thanks

There are two solutions to the forward/backward problem:

1. transpose the wires from the motor speed controller that go to the motor by switching the M+ and M- wires. (I think this is the best solution)
OR
2. in the code, add pwm01 = 255 - pwm01;
pwm02 = 255 - pwm02; // put after any other assignments to pwm01. (I used PWM01 Ind 02, but of course, use the pwm## that the motors use

As for the different speeds, there can be three solutions:
1. calibrate the motor speed controllers
2. in the code,use a lookup table or a function so that the p1_y goes from 0 - 255
3, It may be the motors, They just may go faster in one direction or its the water flowing more efficiently in one direction that the other. Not much you could do about that.

Fix the direction problem first and test in the water. Maybe the speed problem will go away or not be so noticeable.

Let me know what happens

Allan

[mattsavela]

Thanks a lot. We gonna test our robot again in the pool tomorrow. I'll try changing the cords. Also, do you think that someone could add the part Allan suggested into our user routines.c file (I uploaded it). I would really appreciate it because I am new to programming. I'm going to add everyone who helped to our acknowledgements section of our teams tech report.

Thanks a lot