Chief Delphi - [FTC]: Deadbands (axis/motor power restrictions)

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- - [FTC]: Deadbands (axis/motor power restrictions) (http://www.chiefdelphi.com/forums/showthread.php?t=87385)

JohnFogarty

03-11-2010 21:30

[FTC]: Deadbands (axis/motor power restrictions)

Hello fellow programmers!
I am currently working on finding a solution to a probable bug which in being a programmer for the last 2 years never occurred. The base joystick to motor control has a bug in it.

4wd

Code:

motor[motorD]=joystick.joy1_y1;

motor[motorE]=joystick.joy1_y2;

motor[motorF]=joystick.joy1_y2;

motor[motorG]=joystick.joy1_y1;

It preforms the funtion, but one wheel always continues to spin even when the joystick may only be giving a output of 1 or 2. How do you implement dead bands on your analog sticks to control the motor power output.

RCXRM

04-11-2010 12:56

Re: [FTC]: Deadbands (axis/motor power restrictions)

Here is the code we've used to create deadbands:

Code:

if((joystick.joy1_y1 < 5) && (joystick.joy1_y1 > -5)) joystick.joy1_y1 = 0;

motor[motorD]=joystick.joy1_y1;

NalaTI

04-11-2010 13:40

Re: [FTC]: Deadbands (axis/motor power restrictions)

I dont have it right here, but ours is something like:

Code:

// since joysticks return -127 to 127 values, and since motors react in a 

// rance of -100 to 100, this function adds a midpoint deadband and 

// adjusts the speed to be within the expected range.



int deadband(int invalue)

{

   // if the value is between -27 and 27 then use

   // that as the deadband and return 0



   if (abs(invalue) < 27) return 0;

   



   // if the value is negative, add 27 to bring the (-27 to -127) to (0 to -100)

   if (invalue < 0) return invalue + 27;



   // if the value is not > 27 then it already exited, so - 27 and return

 

   return invalue - 27;



}



task main()

{

   motor[motorA] = deadband(joystick.joy1_y1);

   motor[motorB] = deadband(joystick.joy1_x1);

   motor[motorC] = deadband(joystick.joy1_y2);

   motor[motorD] = deadband(joystick.joy1_x2);



}

JohnFogarty

04-11-2010 17:23

Re: [FTC]: Deadbands (axis/motor power restrictions)

Quote:

Originally Posted by RCXRM (Post 979608)

Here is the code we've used to create deadbands:

Code:

if((joystick.joy1_y1 < 5) && (joystick.joy1_y1 > -5)) joystick.joy1_y1 = 0;

motor[motorD]=joystick.joy1_y1;

haha that looks exactly like what I am trying today thanks:D
I'll just see what works best I may end up going with the other idea too but thank you for your help.
John Fogarty
GForce 3864

coollog

04-11-2010 19:03

Re: [FTC]: Deadbands (axis/motor power restrictions)

Another way to do it is

Code:

int threshold = 12;



motor[motorD] = (abs(joystick.joy1_y1) >= threshold) * joystick.joy1_y1;

...

This basically just zeroes any joystick value that is within a threshold of 0.

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