/* 
 * File:   demoCounter.c
 * Author: douglas.armstead
 *
 * Created on April 29, 2015, 9:39 AM
 */
#include <stdio.h>
#include <stdlib.h>
#define _XTAL_FREQ 1000000
#include <xc.h>
#include "cortlandStd.h"

void updatePins(int iL){
    int pins[16];//An array of 16 integers for the 7-segment display.
    int temp;
    /*  SUBLIME ASCII ART
     *          a
     *       -------
     *      |       |
     *     f|       |b
     *      |    g  |
     *       -------
     *      |       |
     *     e|       |c
     *      |       |
     *       -------
     *          d
     * Three of the pins in PORTA and four in PORTB are used as the seven
     * outputs. The LED segments are assigned to the PORT bits as shown below:
     *          PORTA       PORTB
     * pins:    76543210    76543210
     * segments:     cde        bagf
     * NOTE: 0 LIGHTS a segment and 1 makes it DARK
     * since the PIC sinks current from the LED display
     *  Pin     Binary       Symbol Displayed
     */
    pins[ 0] = 0b00000010;      //0
    pins[ 1] = 0b00110111;      //1
    pins[ 2] = 0b01000001;      //2
    pins[ 3] = 0b00010001;      //3
    pins[ 4] = 0b00110100;      //4
    pins[ 5] = 0b00011000;      //5
    pins[ 6] = 0b00001000;      //6
    pins[ 7] = 0b00110011;      //7
    pins[ 8] = 0b00000000;      //8
    pins[ 9] = 0b00110000;      //9
    pins[10] = 0b00100000;      //A
    pins[11] = 0b00001100;      //B
    pins[12] = 0b01001010;      //C
    pins[13] = 0b00000101;      //D
    pins[14] = 0b01001000;      //E
    pins[15] = 0b01101000;      //F
    //           0cdebagf
    //(correspondence between LED segments and pins[] bits)
    
    PORTA=pins[iL]>>4;
    //Use logic to retain the 4 most significant bits of PORTB and
    //replace the 4 least significant bits of PORTB with the 4 LSBs of pins[i].
    temp=PORTB;
    PORTB=(temp|0b00001111)&(pins[iL]|0b11110000);

    return;
}
int main(int argc, char** argv) {
    OSCCONbits.IRCF=0b100; //This is what actually sets the frequency to 1MHz.
    ANSEL=0;
    int i;

    TRISA=0b00000000;   //Set all RA pins as output.
    TRISB=0b01110000;   //Set portB 4-6 as input, rest as outputs
                        //RB4: reset, RB5:bump up, RB6: bump down.


    //Initialize the display to zero
    i=0;
    updatePins(i);
    PORTAbits.RA3=1;
    __delay_ms(150);
    PORTAbits.RA3=0;
    while(1){
        if(PORTBbits.RB4==1){
            i=0;
            updatePins(i);
            __delay_ms(150);
        }
        if(PORTBbits.RB5==1){
            i+=1;
            if(i==16)
                i=0;
            updatePins(i);
            __delay_ms(150);
        }
        if(PORTBbits.RB6==1){
            i-=1;
            if(i==-1)
                i=15;
            updatePins(i);
            __delay_ms(150);
        }

    }
    return (EXIT_SUCCESS);
}