/* ========================================================================== */
/*			PS348_1.C : PWM Control by HSO.1		      */
/* ========================================================================== */
/* Description : Control RC Servo-motor by two external pin interrupts.       */
/* ========================================================================== */
/*
	PS-348 RC Servo Motor : 2.3ms(-90) бн 1.5ms(0) бн 0.7ms(90)
	Let Period = 5.0ms (= 6250 state)
            -90    = 2.3ms (= 2875 state)
              0    = 1.5ms (= 1875 state)
            +90    = 0.7ms (= 875 state)
*/

#pragma dn(0)
#pragma code
#pragma pagelength(32767)
#pragma model(kc)

#include <80c196.h>
#define INT13
#define INT07
#include <isr96.h>
#include <196io.h>
#include <fpal96.h>

const WORD period = 6250; /* 5.0ms */

const WORD hso1_set_time = 0;		/* set time and reset time */
int hso1_reset_time;

void INT13(void);
void INT07(void);

void main(void)
{
  hso1_reset_time = 0;   /* Initial degree is 0 deg */

  lcd_print(" PWM with HSO.1 ", LINE1);		/* display title */
  lcd_print(" Degree is   0 D", LINE2);

  timer2 = 0;					/* timer 2 initial value */

  ioc2 = 0xC0;					/* clear HSO CAM and enable locking */

  wsr = 1;
  t2control = 0x01;				/* timer 2 internal clock source */
  wsr = 0;

  fpinit();            /* For floating Point Arithmetic */

  ioc1 = 0x02;         /* Select pin no. 9 for external Interrupt */
  int_mask = 0x80;
  imask1 = 0x20;
  enable();

/* HSO.1 */

/* Set Period */

  while((ios0 & 0x40) == 0x40);
  hso_command = 0xCE;
/* 11001110
   ||||++++- timer2 reset
   |||+----- HSO Interrupt Disable
   ||+------ Set the selected pin to 0!!!!!!!!!
   |+------- Select timer2
   +-------- CAM Lock                    */

  hso_time = period;   /* 10 */

/* Set Time */

  while((ios0 & 0x40) == 0x40);
  hso_command = 0xE1;
/* 11100001
   ||||++++- Select HSO.1
   |||+----- HSO Interrupt Disable
   ||+------ Set the selected pin to 1!!!!!!!!!
   |+------- Select timer2
   +-------- CAM Lock                    */

  hso_time = hso1_set_time;


/* Reset Time */
  do{
    while((ios0 & 0x40) == 0x40);
    hso_command = 0x41;
    /* 01000001
       ||||++++- Select HSO.1
       |||+----- HSO Interrupt Disable
       ||+------ Set the selected pin to 0!!!!!!!!!
       |+------- Select timer2
       +-------- CAM UnLock                    */
    hso_time = hso1_reset_time;
   }while(1);
}

void INT13(void)
{
	asm pushf;
	hso1_reset_time -= 100;
        if(hso1_reset_time < 875) hso1_reset_time = 875;
	lcd_put3dec((WORD)(-0.09*hso1_reset_time+258.75), LINE2, 11);
	asm popf;    
	return;
}

void INT07(void)
{
	asm pushf;
	hso1_reset_time += 100;
        if(hso1_reset_time > 2875) hso1_reset_time = 2875;
	lcd_put3dec((WORD)(-0.09*hso1_reset_time+258.75), LINE2, 11);
	asm popf;    
	return;
}