View Single Post
  #6   Spotlight this post!  
Unread 15-02-2007, 00:01
benhulett benhulett is offline
Registered User
FRC #1895
 
Join Date: Feb 2007
Location: Manassas
Posts: 28
benhulett is on a distinguished road
Re: Moderating Acceleration / Deceleration

http://www.chiefdelphi.com/forums/sh...ad.php?t=53988

I actually posted about a problem with our code trying to achieve the same purpose....this code works, but is a little sloppy compared to others.

Code:
int Incrementation_Code(int motor_curr, int motor_prev, int padd, int max_step)
{
  int change = 0;
  int RetVal;

  change = motor_curr - motor_prev;

  if (change >= padd)
  {
    //Accelerate
	if (change > max_step)
    {
      RetVal = motor_prev + max_step;
      printf("Motor accelerated by MAX = %d.  ", max_step);
	}
    else
    {
      printf("Motor accelerated by %d.  ", change);
      RetVal = motor_curr;
    }
	
	if ( RetVal > 255 )
	{
      RetVal = 255;
      printf("Detected excess of 255!  ");
    }

  }
  else if (change <= -padd)
  {
    //Decelerate
    if (change < -max_step)
    {
      RetVal = motor_prev - max_step;
      printf("Motor decelerated by MAX = %d.  ", max_step);
    }
    else
    {
      printf("Motor decelerated by %d.  ", change);
      RetVal = motor_curr;
    }

    if (RetVal < 0)
    {
      RetVal = 0;
      printf("Detected below-zero condition!  ");
    }
  }
  else
  {
    //no change
    RetVal = motor_prev;
	printf("No change in motor output value.  ");
  }
  printf("\r\n");
  return RetVal;
}


int last_p1x_val=128;
int last_p1y_val=128;


void Default_Routine(void)
{

	int maximum_step=10; /*change this to change how much the motor increments the speed by*/
	int padding=3;

 /*---------- Analog Inputs (Joysticks) to PWM Outputs-----------------------
  *--------------------------------------------------------------------------
  *   This maps the joystick axes to specific PWM outputs.    */

  p1_y = Incrementation_Code(p1_y, last_p1y_val, padding, maximum_step);
  last_p1y_val = p1_y;
  pwm01 = p1_y;
  pwm02 = p2_y;   
  pwm03 = p3_y;   
  pwm04 = p4_y;   
  p1_x = Incrementation_Code(p1_x, last_p1x_val, padding, maximum_step);
  last_p1x_val = p1_x;
  pwm05 = p1_x;  
  pwm06 = p2_x;   
  pwm07 = p3_x;   
  pwm08 = p4_x;   
  pwm09 = p1_wheel;
  pwm10 = p2_wheel;   
  pwm11 = p3_wheel;   
  pwm12 = p4_wheel;
EDIT: woops, forgot the semi-colons on some of the statements, fixed now

Last edited by benhulett : 15-02-2007 at 00:05.