eccpdemo.c

Hitech microchip PIC C18 Compiler

#include <pic18.h>
#include "eccpdemo.h"
#include <stdio.h>

void interrupt ISR(void);
void init(void);
void set_new_mode(void);

unsigned char MODE=0;
unsigned char OLD_MODE=1;	 /* to force an update immediately */
static volatile bit CAPTURE;

void main(void)
{
	init();
	
	while(1)
	{
		MODE=PORTC&0x0F;	// read the DIP switch
		if(MODE!=OLD_MODE)	// if something has changed...
			{
				set_new_mode();	// ...update the SFRs
			}
		OLD_MODE=MODE;
		
		{
		}
		
		if(CAPTURE)	// if a capture event has happened...
		{
			CAPTURE=0;	// ...display details
			printf("\nCAPTURED at %X\r",TMR3);
		}
		
		if(PWM_MODE)
			update_pwm();
	}
}

void init(void)
{
	GIE=1;	// interrupts are enabled
	PEIE=1;	// peripheral interrupts are enabled
	IPEN=0;
	
	TXEN=1;	/* enable serial port transmissions */
	SPEN=1;	
	TXIE=0;	/* not interrupt driven */		
	
	TRISC=0xBF;
	TRISD=0xFF;
	TRISA=0xFF;
	RBIE=1;		// pushbutton can trigger PORTB interrupt

	ECCPAS=0b00000000;	// no autoshutdown events

	T3CON=0b10001101;	//TMR3 used for CCP module
	T2CON=0x04;	// TMR2 used for PWM

	ECCP1IE=1;	// ECCP mode is interrupt enabled
	ECCP1IF=0;
	ECCPR1=0x0F000;	// Compare events on TMR3 = 0xF000
	
	CAPTURE=0;
}

void interrupt ISR(void)
{
	if((RBIE)&&(RBIF))		// if pushbutton pressed...
	{
		switch(MODE&0x0F)	
		{
			case 0b1000:	// if LED set on compare, pushbutton clears LED	 
				LED=OFF;
				break;
			case 0b1001:	// if LED clear in compare, pushbuton sets LED
				LED=ON;
				break;
			default:
				break;
		}
	RBIF=0;	
	}
	
	if (ECCP_INTERRUPT)
	{
		if(CAPTURE_MODE)
		{
			CAPTURE=1;	// set this flag if a capture event has been detected
		}
		ECCP1IF=0;
	}

}


void putch(unsigned char c)
{
	TXREG=c;	/* transmit a character to Serial IO */
	while(!TXIF)continue;
	TXIF=0;
}

void set_new_mode(void)
{
	printf("\r");

	/* output current mode selected, and set PORTD to
        input (pushbutton) or output (LED/analyser) as the
	mode requires */
	switch(MODE)
	{
		case 2:
			printf("function:COMPARE, TOGGLE ON MATCH    \r");
			TRISD4=0;
			break;
		case 4:
			printf("function:CAPTURE, ON FALLING EDGE    \r");
			TRISD4=1;
			break;
		case 5:
			printf("function:CAPTURE, ON RISING EDGE     \r");
			TRISD4=1;
			break;
		case 6:
			printf("function:CAPTURE, ON 4th RISE        \r");
			TRISD4=1;
			break;
		case 7:
			printf("function:CAPTURE, ON 16th RISE       \r");
			TRISD4=1;
			break;
		case 8:
			printf("function:COMPARE, GO HIGH ON MATCH   \r");
			TRISD4=0;
			break;
		case 9:
			printf("function:COMPARE, GO LOW ON MATCH    \r");
			TRISD4=0;
			break;
		case 0xA:
			printf("function:COMPARE, NO OUTPUT ON MATCH \r");
			TRISD4=0;
			break;
		case 0xB:
			printf("function:COMPARE, DO SPECIAL ON MATCH \r");
			TRISD4=0;
			break;
		case 0xC:
			printf("PWM mode: A&C=Active hi,B&D=Active hi\r");
			TRISD4=0;
			break;
		case 0xD:
			printf("PWM mode: A&C=Active hi,B&D=Active lo\r");
			TRISD4=0;
			break;
		case 0xE:
			printf("PWM mode: A&C=Active lo,B&D=Active hi\r");
			TRISD4=0;
			break;
		case 0xF:
			printf("PWM mode: A&C=Active lo,B&D=Active lo\r");
			TRISD4=0;
			break;
		default:
			printf("function:OFF                         \r");
			TRISD4=0;
			break;
	}
	ECCP1CON=((ECCP1CON&0xF0)+MODE);	// update mode on SFR
}