/*
 * File:   main.c
 * Author: boos
 *
 * Created on March 13, 2021, 12:50 PM
 */

// CONFIG
#pragma config FOSC = INTOSCIO  // Oscillator Selection bits (INTOSC oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF      // RA5/MCLR/VPP Pin Function Select bit (RA5/MCLR/VPP pin function is digital input, MCLR internally tied to VDD)
#pragma config BOREN = ON       // Brown-out Detect Enable bit (BOD enabled)
#pragma config LVP = OFF        // Low-Voltage Programming Enable bit (RB4/PGM pin has digital I/O function, HV on MCLR must be used for programming)
#pragma config CPD = OFF        // Data EE Memory Code Protection bit (Data memory code protection off)
#pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off)

#include <xc.h>


// where are our LEDs?
#define LED1 RB0
#define LED2 RB1
#define LED3 RB2
#define LED4 RB3

// where are our buttons?
#define SW1 RB7
#define SW2 RB6
#define SW3 RB5
#define SW4 RB4

// shortcuts for tristate registers of the buttons
#define TRIS1 TRISB7
#define TRIS2 TRISB6
#define TRIS3 TRISB5
#define TRIS4 TRISB4


// auxiliary function, see below
void wait (void);


// variables
int time;
int avg1, avg2, avg3, avg4;
char thr1, thr2, thr3, thr4;
int buf1, buf2, buf3, buf4; 

// you can adjust the PWM brightness levels here
char pwm_values[] = {0, 20, 100, 255};
char pwm = 0, pwmlevels = 4;


// main function
void main (void) {
    
    
    // set the entire PORTB as an output on startup
    TRISB = 0;
    
    
    // calibrate all buttons
    // (find average discharge times)
    for (char c=0; c<16; c++) {
        
        avg1=0; time=0;
        TRIS1 = 0; SW1 = 1; wait(); TRIS1 = 1; while (SW1==1) { time++; }
        avg1 += time / 16;
        
        avg2=0; time=0;
        TRIS2 = 0; SW2 = 1; wait(); TRIS2 = 1; while (SW2==1) { time++; }
        avg2 += time / 16;
        
        avg3=0; time=0;
        TRIS3 = 0; SW3 = 1; wait(); TRIS3 = 1; while (SW3==1) { time++; }
        avg3 += time / 16;
        
        avg4=0; time=0;
        TRIS4 = 0; SW4 = 1; wait(); TRIS4 = 1; while (SW4==1) { time++; }
        avg4 += time / 16;
        
    }
        
    // set threshold values (play around with these values to make it work for you)
    thr1 = 15; thr2 = 15; thr3 = 15; thr4 = 15;
    
    
    // configure PWM module, frequency: 3.9kHz, resolution: 10bit
    // (more details at www.friendlywire.com/tutorials/pwm)
    
    // PWM resolution: 10 bit
    PR2 = 0xff;
    
    // turn on timer 2 and set its prescaler to 1:1
	T2CON = 0b100;
    
    // turn on PWM module    
	CCP1CON = 0b1100;
    
    // set startup duty cycle value to first entry in our custom PWM array
	CCPR1L = pwm_values[pwm];
    
    
    // main loop
    while (1) {
        
        
        // momentary mode
        time = 0; TRIS1 = 0; SW1 = 1; wait(); TRIS1 = 1; while (SW1==1) { time++; }
        if (time-avg1 > thr1) {
            buf1 = 20;
            LED1 = 1;
        } else {
            if (buf1 > 0) {
                buf1--;
            } else {
                LED1 = 0;
            }
        }
        
        
        // toggle mode
        time = 0; TRIS2 = 0; SW2 = 1; wait(); TRIS2 = 1; while (SW2==1) { time++; }
        if (time-avg2 > thr2) {
            if (buf2 == 0) {
                LED2 = ~ LED2;
            }
            buf2 = 20;
        } else if (buf2 > 0) {
            buf2--;
        }
        
        
        // timer mode (adjust duration with variable "buf3")
        time = 0; TRIS3 = 0; SW3 = 1; wait(); TRIS3 = 1; while (SW3==1) { time++; }
        if (time-avg3 > thr3) {
            buf3 = 500;
            LED3 = 1;
        } else {
            if (buf3 > 0) {
                buf3--;
            } else {
                LED3 = 0;
            }
        }
        
        
        // dimmer mode (adjust dimming values in the array "pwm_values")
        time = 0; TRIS4 = 0; SW4 = 1; wait(); TRIS4 = 1; while (SW4==1) { time++; }
        if (time-avg4 > thr4) {
            if (buf4 == 0) {
                pwm++;
                if (pwm >= pwmlevels) {
                    pwm = 0;
                }
                CCPR1L = pwm_values[pwm];
            }
            buf4 = 20;
        } else if (buf4 > 0) {
            buf4--;
        }
        
        
    }
    
}

// this function waits for eight cycles and does nothing
// (we need this so the stray capacity can charge up enough)
void wait (void) {
    
    NOP(); NOP(); NOP(); NOP();
    NOP(); NOP(); NOP(); NOP();
    
}