// ---  Lab6. -------------------
//
// This program impliments PWM controller for the speed of
// a DC servo motor. 
//
// I/O Connections:
//    RC2 = PWM output to the motor
//    RA0 = analog input to set the speed
//    RC6,RC7 = SCI input to control the speed via a keybaord
//
// Debug Lights
//    RC0 = pulses every time there a byte is read in
//    RC1 = pulses every INT interrupt (1/1000 rotation)
//    RC3 = pulses every 10ms
//    RC4 = pulses every 100ms (sampling rate)
//    RC5 = heart beat.  Pulses each loop through the main routine
//
// Several interrupts are used
//    Timer2:    every 10ms for timing
//    Capture1:  used for PWM output
//    RCI:       used for receiving serial data (19200 baud)
//    INT:       measure the speed by counting edges / 100ms
//
//  Revision History
//    April 17, 2005:  Intial version - JSG
//        Total ROM used      850 words (41.5%)
//        Total RAM used       64 bytes (36.4%)



// Global Variables

unsigned int  Counter1;   // total pulses counted so far
unsigned int  Counter2;   // # of TMR2 interrupts seen
unsigned int  SPEED;      // # egdes / 100ms (100*rev/sec)
unsigned int  REF;        // desired speed (100*rev/sec)


bank1 unsigned char MSG[10];     // sci message coming in
bank1 unsigned char MSG_LENGTH;  // length of message
bank1 unsigned char TEMP;        // temp variable
bank1 unsigned char N;           // temp length of message
bank1 unsigned char FLAG;        // 1 means carriage return seen

const unsigned char MSG0[10] = "SCI Data: ";
const unsigned char MSG1[10] = "Ref:      ";
const unsigned char MSG2[10] = "Capture1: ";
const unsigned char MSG3[10] = "Speed:    ";



// Subroutine Declarations
#include	<pic.h>

static volatile unsigned int Timer1 @ 0x0E;
static volatile unsigned int Capture1 @ 0x15;


#include        "lcd_20x4.h"
#include        "function.h"
#include        "a2d.h"



// Subroutines
#include        "lcd_20x4.c"
#include        "function.c"
#include        "bootloader.c"
#include        "a2d.c"


// Interrupt service routine


void interrupt IntServe(void) @ 0x10
{
   if (RCIF) {
      RC0 = !RC0;    // debug info for RCIF interrupts
      TEMP = RCREG;
      while(!TRMT); TXREG = TEMP;
      MSG[N] = TEMP;
      N += 1;
      if (N > 9) N = 9;
      if (TEMP == 13) {
         FLAG = 1;
         MSG_LENGTH = N;
         N = 0;
         }

      RCIF = 0;
      }
   if (INTF) {
      RC1 = !RC1;    // debug I/O for INT interrupts
      Counter1 += 1;
      INTEDG = !INTEDG;

      INTF = 0;
      }
   if (TMR2IF) {
      RC3 = !RC3;    // debug I/O for TMR2 interrupts
      Counter2 += 1;
      if (Counter2 > 9) {   // every 100ms...
         SPEED = Counter1;
         Counter1 = 0;
         Counter2 = 0;
         RC4 = !RC4;
         }
      TMR2IF = 0;
      }
   if (TMR1IF) {
      RC2 = 1;
      TMR1IF = 0;
      }
   if (CCP1IF) { 
      RC2 = 0;
      CCP1IF = 0; 
      }
   }

void SCI_Out(unsigned int Data)
{
   unsigned char A[5];
   unsigned char i;

   for (i=0; i<5; i++) {
      A[i] = Data % 10;
      Data = Data / 10;
      }

   while(!TRMT);  TXREG = ascii(A[4]);
   while(!TRMT);  TXREG = ascii(A[3]);
   while(!TRMT);  TXREG = ascii(A[2]);
   while(!TRMT);  TXREG = ascii(A[1]);
   while(!TRMT);  TXREG = ascii(A[0]);
   while(!TRMT);  TXREG = 32;
   }

void LCD_Out(unsigned int DATA)
{
   unsigned char A[5], i;

   for (i=0; i<5; i++) {
      A[i] = DATA % 10;
      DATA = DATA / 10;
      }
   lcd_write(ascii(A[4]));
   lcd_write(ascii(A[3]));
   lcd_write(ascii(A[2]));
   lcd_write(ascii(A[1]));
   lcd_write(ascii(A[0]));
   lcd_write(' ');
   }


// Main Routine

void main(void)
{
   unsigned char i;
   unsigned int A2D;
   unsigned char A[5];

   TRISB  = 0x00;               
   TRISC  = 0x00;
   TRISA  = 0x00;
   ADCON1 = 6;

   PORTC = 0;
   PORTB = 0;
   PORTA = 0;

   FLAG = 0;

   Wait_ms(100); 
   lcd_init();                  // initialize the LCD
   Wait_ms(100);
   lcd_move(0,0);
   for (i=0; i<10; i++) lcd_write(MSG0[i]);
   lcd_move(1,0);
   for (i=0; i<10; i++) lcd_write(MSG1[i]);
   lcd_move(2,0);
   for (i=0; i<10; i++) lcd_write(MSG2[i]);
   lcd_move(3,0);
   for (i=0; i<10; i++) lcd_write(MSG3[i]);


// Initialize Serial Port
   TRISC = TRISC | 0xC0;
   TXSTA = 0x22;           // 8-bit no parity
   RCSTA = 0x90;           // continuous receive
   TXIE  = 0;              // no interrupt on xmit
   RCIE  = 1;              // no interrupt on receive
   BRGH  = 1;
   SPBRG = 64;             // 19200 baud @ 20MHz = 64
   SYNC  = 0;

// initialize INT interrupts
   INTE = 1;
   INTEDG = 1;

// initialize Timer2 interrupts for 10ms
    T2CON  = 0x77; 
    PR2    = 207; 
    TMR2IE = 1;
    PEIE   = 1;

// Initialize Timer1.  When Timer1 = 0, set RC2.
   T1CON  = 0;
   TMR1CS = 0;
   TMR1ON = 1;
   TMR1IE = 1;

// Initialize Timer1 Capture.  When Timer1 = Capture1, clear RC2
   CCP1CON = 0x0A;
   CCP1IE = 1;


   TRISC2 = 0;

   A2D_Init();

   GIE     = 1;

   REF = 0;
   Capture1 = 100;

   do {

      lcd_move(0,10);
      for (i=0; i<10; i++) lcd_write(MSG[i]);

      REF = A2D_Read(0);
      Capture1 += (REF - SPEED);

      lcd_move(1,10);
      LCD_Out(REF);
      SCI_Out(REF);

      lcd_move(2,10);
      LCD_Out(Capture1);
      SCI_Out(Capture1);

      lcd_move(3,10);
      LCD_Out(SPEED);
      SCI_Out(SPEED);

 
      while(!TRMT); TXREG = 13;   // carriage return
      while(!TRMT); TXREG = 10;   // line feed

      RC5 = !RC5;   // heart beat


      } while (1>0);
   }