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stepper.c

stepper.hex

/*

* STEPPER.C

* sweeping stepper's rotor cw and cww 400 steps

* Copyright (c) 1999 by W.Sirichote

*/

#include c:\mc51\8051io.h /* include i/o header file */

#include c:\mc51\8051reg.h

register unsigned char j,flag1,temp;

register unsigned int cw_n,ccw_n;

unsigned char step[8]={0x80,0xc0,0x40,0x60,0x20,0x30,0x10,0x90}

#define n 400

/* flag1 mask byte

0x01 run cw()

0x02 run ccw()

*/

main()

{

flag1=0;

serinit(9600);

disable(); /* no need timer interrupt */

cw_n = n; /* initial step number for cw */

flag1 |=0x01; /* initial enable cw() */

while(1){

{

tick_wait(); /* wait for 10ms elapsed */

energize(); /* round-robin execution the following tasks every 10ms */

cw();

ccw();

}

}

}

cw(){

if((flag1&0x01)!=0)

{

cw_n--; /* decrement cw step number */

if (cw_n !=0)

j ; /* if not zero increment index j */

else

{flag1&=~0x01; /* disable cw() execution */

ccw_n = n; /* reload step number to ccw counter */

flag1 |=0x02; /* enable cww() execution */

}

}

}

ccw(){

if((flag1&0x02)!=0)

{

ccw_n--; /* decremnent ccw step number */

if (ccw_n !=0)

j--; /* if not zero decrement index j */

else

{flag1&=~0x02; /* disable ccw() execution */

cw_n = n; /* reload step number to cw counter */

flag1 |=0x01; /* enable cw() execution */

}

}

}

tick_wait(){ /* cputick was replaced by simpler ASM code 10ms wait */

asm' JNB TCON.5,*'; /* wait for TF0 set */

asm' CLR TCON.5'; /* clear TF0 for further set */

asm' ORL TH0,#$DC'; /* reload TH0 with $DC, TL0 = 0 */

}

energize(){

P1 = step[(j&0x07)]; /* only step 0-7 needed */

}