// PIC Project Board
// PIC18F2550 + LTC2400 + LCD + USB
// Sample code demonstrates the use of sigma-delta converter.
// The program prints analog input 0-2.5V on LCD in micro Volts unit
// source code was compiled with Mikro-C compiler
// Copyright 2006 Wichit Sirichote, kswichit@kmitl.ac.th

#define ADC_CS1 PORTC.F0   // output bit
#define ADC_SDO PORTC.F1  // input bit
#define ADC_SCK PORTC.F2  // output bit


char *text = "PICProject Board";

unsigned long x1,x2,x3,x4,x5;

/* read 32-bit data from LTC2400 */

unsigned long read_ADC1(void)
{
   char k;
   long n;
   n= 0;
   ADC_CS1 = 0;
   for(k=0; k<32; k++)
   {
         n<<= 1;
     ADC_SCK = 1;
     n |= ADC_SDO;
	 ADC_SCK = 0;
    }
	ADC_CS1 = 1;
         n&=0x01fffffff; // maskout sign bit
         n>>=4;   // get 24-bit conversion result
     return n;
}

/* 5-point moving average */
// return data that scaled with reference voltage in uV unit
unsigned long filter_ADC(void)
{
    x5 = x4;
    x4 = x3;
    x3 = x2;
    x2 = x1;
    x1 = read_ADC1();
    return ((((x1+x2+x3+x4+x5)/5)*148)/100); // x 149 E-9 convert to 2.479V
}


void main() {

  char buffer[20];
  long d;

  ADCON1 = 0x0E;
  TRISB = 0;                // PORTB is output
  PORTC = 0xFF;
  TRISC = 0x02;             // PORTC.1 is input bit
  Lcd_Init(&PORTB);         // Initialize LCD connected to PORTB
  Lcd_Cmd(Lcd_CLEAR);       // Clear display
  Lcd_Cmd(Lcd_CURSOR_OFF);  // Turn cursor off
  Lcd_Out(1, 1, text);

  while(1)
  {
  PORTC.F7 ^= 1;
  d = filter_ADC();
  sprintl(buffer,"%08ld x0.1%cV",d,0xe4);
  Lcd_Cmd(LCD_SECOND_ROW);
  Lcd_Out_CP(buffer);
  Delay_ms(200);

  }
  
}