Motor Test Code:
 

#include <Mega32.h>

#include <Stdio.h>

#include <Stdlib.h>

#include <delay.h>

 

//#define prescale0 3

#define begin {

#define end }

#define t0 20 

       

void initialize(void);

 

unsigned int time0;

unsigned char step;                                                                            

 

//**********************************************************

//timer 0 compare ISR

interrupt [TIM0_COMP] void timer0_compare(void)

begin      

  //Decrement the three times if they are not already zero

  

   

  if (time0 > 0) --time0;

  

end  

 

//**********************************************************     

 

//Set it all up

void initialize(void)

begin 

     

 

  //set up timer 0  

  TIMSK=2;        //turn on timer 0 cmp match ISR 

  OCR0 = 250;     //set the compare re to 250 time ticks

      //prescalar to 64 and turn on clear-on-match

  TCCR0=0b00001011;     

 

 

  //set up the ports

  DDRB=0x00;      // PORT B- input is bottom nibble, output is top nibble, for pushbuttons

  PORTB=0xff;

  DDRC=0xff;    // PORT C is an output port for motor control

  PORTC=0x00;

  

  

  //init the task timer

  time0=t0;

  step=0;

  stepcount=0;  

      

  //crank up the ISRs

  #asm

      sei

  #endasm 

end

 

void main(void)

begin

  initialize();

  while(1)

  begin

    if(time0 == 0)

    begin

      time0 = t0;

   

                  if (~PINB == 0x01)  //move motors forwrd

                  begin

                        if (step > 0)

                              step--;

                        else step = 3;

                  end

                  else if (~PINB == 0x02)  //move motors backwards

                  begin

                        if (step < 3)

                              step++;

                        else step = 0;

                  end

                        

 

                  if (step == 0) PORTC = 1+128;

                  if (step == 1) PORTC = 2+64;

                  if (step == 2) PORTC = 4+32;

                  if (step == 3) PORTC = 8+16;        

                   

            end

   end

end