/*******************************************************************
 * Processor:       PIC18F4520
 * Compiler:        MPLAB C18
 *
 * Author Key
 ********************************************************************/

/** Header Files ***************************************************/
#include <p18f4520.h>
#include <stdio.h>
#include <adc.h>

/** Configuration Bits *********************************************/
#pragma config OSC = INTIO67
#pragma config WDT = OFF
#pragma config LVP = OFF
#pragma config BOREN = OFF
#pragma config XINST = OFF

/** Define Constants Here ******************************************/
#define ACD_LOW_THRESHOLD 409
#define ACD_HIGH_THRESHOLD 818
#define PRESSED 0

/** Local Function Prototypes **************************************/

/** Global Variables ***********************************************/
int horzJoystick;
int isUpdating = 1;

/*******************************************************************
 * Function:        void main(void)
 ********************************************************************/
#pragma code

void main(void) {
    // Set the clock to 4 MHz
    OSCCONbits.IRCF2 = 1;
    OSCCONbits.IRCF1 = 1;
    OSCCONbits.IRCF0 = 0;

    // Pin IO Setup
    OpenADC(ADC_FOSC_8 & ADC_RIGHT_JUST & ADC_12_TAD,
            ADC_CH0 & ADC_INT_OFF & ADC_REF_VDD_VSS,
            0x0B); // Four analog pins
    TRISA = 0xFF; // All of PORTA input
    TRISB = 0xFF; // All of PORTB input
    TRISC = 0x00; // All of PORTC output
    TRISD = 0x00; // All of PORTD output
    PORTC = 0x00; // Turn off all 8 Port C outputs

    while (isUpdating) {
        SetChanADC(ADC_CH2); // Select the pin
        ConvertADC(); // Start conversion
        while (BusyADC()); // Wait for completion
        horzJoystick = ReadADC(); // Read result

        if (horzJoystick < ACD_LOW_THRESHOLD) {
            PORTCbits.RC0 = 1;
            PORTCbits.RC7 = 0;
            if (PORTAbits.RA4 == PRESSED) {
                isUpdating = 0;  // There are many solutions to part 2B
            }
        } else if (horzJoystick > ACD_HIGH_THRESHOLD) {
            PORTCbits.RC0 = 0;
            PORTCbits.RC7 = 1;
            if (PORTAbits.RA4 == PRESSED) {
                isUpdating = 0;
            }
        } else {
            PORTC = 0x00;
        }
    }

    while (1) {
        // Stop responding to ADC readings.
    }
}