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

#include "p24fj64ga002.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 )

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

typedef struct tagLEDs {
	union {
		struct {
			unsigned :4;
			unsigned LED4:1;
			unsigned LED5:1;
			unsigned LED6:1;
			unsigned LED7:1;
		};
		struct {
			unsigned :4;
			unsigned lower:2;
			unsigned upper:2;
		};
		struct {
			unsigned :4;
			unsigned all:4;
		};
	};
} LEDS;

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

// Assigns LEDs configuration from input variable to upper 4 bits of LATB.
void OutputLEDs(LEDS leds)
{
	_LATB15 = leds.LED4;
	_LATB14 = leds.LED5;
	_LATB13 = leds.LED6;
	_LATB12 = leds.LED7;
}

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

int main(void)
{
	LEDS leds;
	
	// TRISB controls direction for all PORTB pins, where 0 -> output, 1 -> input.
	// Configure RB15-RB12 as outputs.
	_TRISB15 = 0;
	_TRISB14 = 0;
	_TRISB13 = 0;
	_TRISB12 = 0;
	
	// Configure RB5 as input
	_TRISB5 = 1;
	
	// Initialize LEDs to off
	leds.LED4 = 1;
	leds.LED5 = 1;
	leds.LED6 = 1;
	leds.LED7 = 1;
	OutputLEDs(leds);
	
	// Set Timer1's Prescaler to 1:1
	T1CONbits.TCKPS = 0;
	
	// Set Timer 1's period value regsiter to value for 2ms. Please note 
	// T1CON's register settings below (internal Fosc/2 and 1:1 prescaler).
	// 
	//    Fosc     = XTFREQ * PLLMODE
	//             = 7372800 * 4
	//             = 29491200
	// 
	//    Fosc/2   = 29491200 / 2
	//             = 14745600
	//
	//    Timer 1 Freq = (Fosc/2) / Prescaler
	//                 = 14745600 / 1
	//                 = 14745600
	//
	//    PR1 = 2 ms / (1 / (T1 Freq))
	//        = 2e-3 / (1 / 14745600) 
	//        = 2e-3 * 14745600
	//        = 29491.2
	PR1 = 29491;			
	
	// Clear Timer value (i.e. current tiemr value) to 0
	TMR1 = 0;				
	
 	// Start Timer 1
	T1CONbits.TON = 0;
	
	while(1)
	{
		// Off Phase
		leds.LED4 = 1;
		OutputLEDs(leds);
		while (IFS0bits.T1IF == 0);
		IFS0bits.T1IF = 0;
		
		// On Phase
		leds.LED4 = 0;
		OutputLEDs(leds);
		while (IFS0bits.T1IF == 0);
		IFS0bits.T1IF = 0;
	}
	return 0;
}

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