程序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 */ }