Svenska ElektronikForumet

Kod: Markera allt

#include <p18f4550.h>
#include <delays.h>

#pragma config FOSC = HS // High-speed oscillator
#pragma config WDT = OFF // Watchdog timer off

typedef unsigned char uint8_t;

unsigned int adc_in; // Stores the ADC value
unsigned int pe_temp; // Peliter element temperature
int digit; // Digit to display on LED-segment
int digit_res; // The rest of the ADC value when digit has been subtracted
unsigned int i; // used in a for loop
uint8_t n;  // the element to lookup in adc_to_t[64]
static const uint8_t seg_disp[10] = {
	0b11101110,
	0b01100000, 
	0b11001101, 
	0b11101001, 
	0b01100011, 
	0b10101011, 
	0b10101111, 
	0b11100000, 
	0b11101111, 
	0b11100011}; // 10 digits: 0-9
static const uint8_t seg_nbr[4] = {
	0b00000000, // Display off
	0b00000001, // 3rd digit
	0b00000010, // 2nd digit
	0b00000100}; // 1st digit or minus
static const int adc_to_t[64] = { // ADC to temperature for 6 MSBs
	-7047, -7047, -6307, -5841, -5492, -5208, -4966, -4754,
	-4564, -4390, -4230, -4080, -3939, -3805, -3677, -3554,
	-3436, -3321, -3209, -3101, -2994, -2890, -2787, -2685,
	-2585, -2485, -2386, -2288, -2190, -2091, -1993, -1894,
	-1807, -6306, -1593, -1491, -1387, -1282, -1174, -1065,
	-952, -837, -719, -597, -471, -340, -204, -61,
	88, 246, 413, 591, 782, 989, 1215, 1464,
	1742, 2059, 2426, 2865, 3410, 4130, 5187, 7133};

void main(){
	TRISD = 0; // Set port D to output
	TRISE = 0; // Set port E to output
	LATD = seg_disp[0]; // Set the 7-segment display to 0 initially
	LATE = seg_nbr[0]; // Display off
	PORTA = 0b00000110; // Clear port A to prevent if from affecting TRISA
	ADCON1 = 0b00001110; // VSS, VDD ref. AN0  analogue
	TRISA = 0b00000111; // Set port A bit 0-2 to inputs
	ADCON0 = 0b00000001; // channel 0 as input
	ADCON2 = 0b10001000; // ADCON2 setup: Right justified, Tacq=2Tad, Tad=2*Tosc (or Fosc/s)
	pe_temp = 633; // Initially set the desired temperature to -10 C

	while(1){
				
		if(PORTAbits.RA1 == 1) Delay10KTCYx(20); // Delay 10 ms if key is pressed
		if(PORTAbits.RA1 == 1) adc_in = pe_temp; // If key is still pressed display the default peltier temperature
		
		else{ // read thermistor
			ADCON0bits.GO_DONE = 1; // Start A/D Conversion
			while(ADCON0bits.GO_DONE != 0); // Just loop until A/D conversion is done
			adc_in = ADRES; // Take all the 10 bits of the adc
		}
		
		for(i = 0; i < 35535; i++){ // Flash LEDs for a while
			n = adc_in/16; // Lookup table index
			digit_res = adc_to_t[n]/100; // temperature from table
			digit_res += ((adc_in - (int)n*16)*(adc_to_t[n+1] - adc_to_t[n]))/1600; // Temperature correction by interpolation
			if(digit_res > 0){ // If temperature above 0 C
				digit = digit_res/100;
				digit_res = digit_res - digit*100;
				LATD = seg_disp[digit];
			}
			else{ // If temperature below 0 C
				digit = - digit_res/100;
				digit_res = - digit_res - digit*100;
				LATD = 0b00000001; // Set a minus sign
			}	
			LATE = seg_nbr[3]; // Flash digit or minus sign
			Delay10KTCYx(1);

			digit = (unsigned int)digit_res/10;
			digit_res = digit_res - digit*10;
			LATD = seg_disp[digit];
			LATE = seg_nbr[2];
			Delay10KTCYx(1);

			LATD = seg_disp[digit_res];
			LATE = seg_nbr[1];
			Delay10KTCYx(1);
		}
	}
}

Kod: Markera allt

	PORTA = 0b00000000; // Clear port A to prevent if from affecting TRISA
	UCONbits.USBEN = 0; // USB disabled
	CMCON = 0b00000111; // Comparators OFF
	ADCON1 = 0b00001110; // VSS, VDD ref. AN0  analogue
	ADCON0 = 0b00000001; // ADC module enabled. Only AN0.
	ADCON2 = 0b10101000; // ADCON2 setup: Right justified, Tacq=12Tad, Tad=2*Tosc (or Fosc/s)
	TRISA = 0b00000111; // Set port A bit 0-2 to inputs