/* Stepping motor tachometer  1996.6.26 - 6.27 - 7.2 */
/* 1996.9.8 3mode->2mode
/* LSIC-80 */
/* CPU:AKI-80(12.25MHz)  ROM:HN27C256HG-70 */

#include <stdrom.h>

#define APD 0x1c
#define APC 0x1d
#define BPD 0x1e
#define BPC 0x1f

#define abs(a) ((a)>=0?(a):(-(a)))

unsigned char m[4]={0x10,0x20,0x40,0x80};

/* n=0~5041 (msec) for 12.25MHz */
void delay(unsigned int n)
{
	char a=25;
	unsigned int c;
	if(n==0)return;
	c=n*13;
	while(a--){
		n=c;
		while(n--);
	}
}

void PortInit(void)
{
	outp(APC,0xcf); /* mode=3 */
	outp(APC,0xff); /* (0:OUT 1:IN) all bit in  cnt7-0 */
	outp(BPC,0xcf); /* mode=3 */
	outp(BPC,0x0f); /* bit7-4:OUT to step.m.  bit3-0:IN sw,cnt10,9,8 */
}


/* delay=5 ... 1rpm */

void main(void)
{
	int mode;
	unsigned int tacho;
	unsigned int cur_pos;
	unsigned int tmp_pos;
	unsigned int des_pos;
	PortInit();

	mode=0;
	cur_pos=30;
	for(;;){
		/* UCW */
		outp(BPD,m[(--cur_pos)&3]); delay(10);
		if(cur_pos==0)break;
	}
	des_pos=cur_pos;
	delay(250);

	tacho=inp(APD)+(inp(BPD)&7)*0x100;
	for(;;){
		if(tacho!=(inp(APD)+(inp(BPD)&7)*0x100))break;
	}

cont:
	/* mode   0:normal 1:zero (2:maximum) */
	if((inp(BPD)&8)==0){;
		mode=(mode+1)%2;
		delay(250);
	}

	tacho=inp(APD)+(inp(BPD)&7)*0x100;
	if(tacho==0){
		;
	}else{
		tmp_pos=3000U/tacho;
		if(tmp_pos<=100)des_pos=tmp_pos;
	}

	if(mode==1)des_pos=0;

	if(abs(cur_pos-des_pos)>1){
		if(cur_pos<des_pos){
			outp(BPD,m[(++cur_pos)&3]); delay(5);
		}else if(cur_pos>des_pos){
			outp(BPD,m[(--cur_pos)&3]); delay(5);
		}
	}else{
		delay(20);
	}
	goto cont;
}

/* End of File */