// ******************************************************************************************* //
// Include file for PIC24FJ64GA002 microcontroller. This include file defines
// MACROS for special function registers (SFR) and control bits within those
// registers.

#include "p24fj64ga002.h"
#include <stdio.h>

// ******************************************************************************************* //
// Configuration bits for CONFIG1 settings. 
//
// Make sure "Configuration Bits set in code." option is checked in MPLAB.
// This option can be set by selecting "Configuration Bits..." under the Configure
// menu in MPLAB.
//
// These settings are appropriate for debugging the PIC microcontroller. If you need to 
// program the PIC for standalone operation, change the COE_ON option to COE_OFF.

_CONFIG1( JTAGEN_OFF & GCP_OFF & GWRP_OFF & 
		 BKBUG_ON & COE_ON & ICS_PGx1 & 
		 FWDTEN_OFF & WINDIS_OFF & FWPSA_PR128 & WDTPS_PS32768 )

// ******************************************************************************************* //
// Configuration bits for CONFIG2 settings.
// Make sure "Configuration Bits set in code." option is checked in MPLAB. 
// This option can be set by selecting "Configuration Bits..." under the Configure
// menu in MPLAB.

_CONFIG2( IESO_OFF & SOSCSEL_SOSC & WUTSEL_LEG & FNOSC_PRIPLL & FCKSM_CSDCMD & OSCIOFNC_OFF &
		 IOL1WAY_OFF & I2C1SEL_PRI & POSCMOD_XT )

// ******************************************************************************************* //
// Defines to simply UART's baud rate generator (BRG) regiser
// given the osicllator freqeuncy and PLLMODE.

#define XTFREQ     7372800         	  // On-board Crystal frequency
#define PLLMODE    4               	  // On-chip PLL setting (Fosc)
#define FCY        (XTFREQ*PLLMODE)/2  // Instruction Cycle Frequency (Fosc/2)

// ******************************************************************************************* //

// TODO: Deteremine Pulse Width Modulation period and prescaler for desried PWM freqeuncy.

#define PWM_PRESCALER // TODO
#define PWM_PERIOD    // TODO

// ******************************************************************************************* //

// #defines used for assigning the duty cycle regsiters (OCxRS) with descriptive names.

#define R_LED OC2RS
#define G_LED OC3RS
#define B_LED OC4RS

// ******************************************************************************************* //

// Varaible used for controlling when to update the r, g, b varaiables to create the desired
// light pattern.

volatile unsigned char ledUpdate = 0;

// ******************************************************************************************* //

int main(void)
{	
	// Varaibles for storing the current r, g, and b values used to control the 
	// the RGB LED
	long r = 0;
	long g = 0;
	long b = 0;
	
	
	// ******************************************************************************* //
	
	// TODO: Configure peripheral pin mapping to connect Ouptut Compare Modules
	// 2, 3, and 4 to RP12, RP13, and RP14 respectively.
	RPOR6bits.RP12R = ;		
	RPOR6bits.RP13R = ;		
	RPOR7bits.RP14R = ;		
	
	// ******************************************************************************* //
	
	// Configure Timer 2 as clock source for Output Compare Modules 2, 3 and 4. The 
	// prescaler and perioid register value will define the PWM frequency.
	T2CONbits.TCKPS = PWM_PRESCALER;
	PR2 = PWM_PERIOD;			
	TMR2 = 0; 		   	   
	
	// Configures output compare clock source as Timer 2. Setting the OCTSEL will
	// select between Timer 2 and Timer 3 as the clock source (0 -> Timer 2, 1 -> Timer 3).
	OC2CONbits.OCTSEL = 0;
	OC3CONbits.OCTSEL = 0;
	OC4CONbits.OCTSEL = 0;
	
	// Configure Output Compare Modules 2, 3, and 3 for Pulse Width Modulation (PWM).
	OC2CONbits.OCM = 6;
	OC3CONbits.OCM = 6;
	OC4CONbits.OCM = 6;
	
	// Calculate initialize duty cycles for red, green, and blue LEDs
	R_LED = r * PWM_PERIOD / 255;
	G_LED = g * PWM_PERIOD / 255;
	B_LED = b * PWM_PERIOD / 255;
	
	// Initialize OCxR duty cycle registers. 
	OC2R = R_LED;
	OC3R = G_LED;
	OC4R = B_LED;
	
	// Start Timer 2 to generate the PWM output
	T2CONbits.TON = 1; 
	
	// ******************************************************************************* //
	
	ledUpdate = 0;
	
	// ******************************************************************************* //
	
	// Set Timer 1' prescalar to 1:256
	T1CONbits.TCKPS = 3;
	
	// Set Timer 1 period value regsiter to value for 1ms. Please note 
	// T1CON's register settings below (internal Fosc/2 and 1:256 prescalar).
	// 
	//    Fosc     = XTFREQ * PLLMODE
	//             = 7372800 * 4
	//             = 29491200
	// 
	//    Fosc/2   = 29491200 / 2
	//             = 14745600
	//
	//    Timer Freq = (Fosc/2) / Prescaler
	//               = 14745600 / 256
	//               = 57600
	//
	//    PRy = 1ms / (1 / (T1 Freq)) - 1
	//        = 1e-3 / (1 / 57600) - 1
	//        = 1e-3 * 57600 - 1
	//        = 57.6 - 1 
	//        = 57 (approximately)
	PR1 = 57;			
	TMR1 = 0; 		   // Clear Timer 1
	IFS0bits.T1IF = 0; // Clear Timer 1 interrupt flag	
	IEC0bits.T1IE = 1; // Enable Timer 1 interrupt  
	T1CONbits.TON = 0; // Start Timer 1
	
	// ******************************************************************************* //
	
	while(1)
	{
		if( ledUpdate ) {
			ledUpdate = 0;
			
			
			// TODO: Update r, g, and b variables to desried values.
			
			// Update duty cycles for red, green, and blue LEDs
			R_LED = r * PWM_PERIOD / 255;
			G_LED = g * PWM_PERIOD / 255;
			B_LED = b * PWM_PERIOD / 255;
		}		
	}
	
	return 0;
}

// ******************************************************************************************* //

// Timer 1 interrupt asserts an ledUpdate variable that is accessed in the main execution loop
// for updating the r, g, b values for the LEDs.

void _ISR _T1Interrupt(void)
{
	// Clear Timer 1 interrupt flag to allow another Timer 1 interrupt to occur.
	IFS0bits.T1IF = 0;		
	
	ledUpdate = 1;
}

// ******************************************************************************************* //