PIC Remote - 2013-03-15

#include <xc.h>
#include <pic12f617.h>

#pragma config WRT=OFF //Disable write protection
#pragma config FOSC=INTOSCIO //Use internal clock, with I/O on clock pins.
#pragma config MCLRE=OFF //Use MCLRE as an input pin.
#pragma config WDTE=OFF //Disable Watchdog Timer
#pragma config IOSCFS=4MHZ //Run at 4MHz
#pragma config CP=OFF //No code protection
#pragma config PWRTE=OFF //Enable Power-Up-Timer
#pragma config BOREN=OFF //Disable Brownout reset

char transmit_codes[5] = {0b1000, 0b1001, 0b1010, 0b1011, 0b1100};

void transmit(char code)
{
    char value = transmit_codes[code]; //Copy the code

    //Output bit 4
    if((value & 0b1000) == 0)
        GPIO = 0x00;
    else
        GPIO = 0x01;

    _delay(50000);

    //Output bit 3
    if((value & 0b100) == 0)
        GPIO = 0x00;
    else
        GPIO = 0x01;

    _delay(50000);

    //Output bit 2
    if((value & 0b10) == 0)
        GPIO = 0x00;
    else
        GPIO = 0x01;

    _delay(50000);

    //Output bit 1
    if((value & 0b1) == 0)
        GPIO = 0x00;
    else
        GPIO = 0x01;

    _delay(50000);

    GPIO = 0;
}

void interrupt isr(void)
{
    INTCONbits.GPIF = 0; //Clear flag.
    INTCONbits.GPIE = 0; //Disable interrupts to avoid triggering twice.
    _delay(10000); //Can probably scrap this now.
    return;
}

void main()
{
    WPU = 0xFF; //Enable all pull-up resistors.
    GPIO = 0; //Clear all pins.
    ANSEL = 0; //All pins digital inputs, rather than analogue.
    TRISIO = 0b11111110; //RB0 output, others inputs.
    OPTION_REG = 0; //Enable pull-ups globally.

    INTCON = 0b10001000; //Enable global and GPIO change interrupts.
    IOC = 0b11111110; //Enable interrupt-on-change for all pins.

    while(1)
    {
        if(GPIObits.GP1 == 0)
            transmit(0);
        else if(GPIObits.GP2 == 0)
            transmit(1);
        else if(GPIObits.GP3 == 0)
            transmit(2);
        else if(GPIObits.GP4 == 0)
            transmit(3);
        else if(GPIObits.GP5 == 0)
            transmit(4);

        while((GPIO &= 0b00111110) != 0b00111110); //Wait for button to be released.

        INTCONbits.GPIE = 1; //Re-enable interrupts before sleeping.
        SLEEP();
    }

    return;
}