// ******************************************************************************************* //
// 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 )

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

#define DELAY_AMOUNT 10000

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

typedef enum stateTypeEnum {WaitForPress, WaitForRelease, LEDToggle, 
	                        DebouncePress, DebounceRelease} stateType;

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

int main(void)
{
	int i;
	stateType state;
	
	// TRISB controls direction for all PORTB pins, where 0 -> output, 1 -> input.
	// Configure RB15 as output.
	//
	// TODO: Configure TRIS bit for RB15 as output
	
	// AD1PCFG is a register for configuring input pins between analog input
	// and digital IO, where 0 -> analog (default), 1 -> digital. PCFG4 is
	// the configuration bit for input AN4, which is mapped to the same pin
	// as digital input RB2. We want to use RB2 to connect to an input switch. 
	//
	// TODO: Configure AD1PCFG register for configuring input pins between analog input
	// and digital IO.
	
	// Configure RB2 as input
	//
	// TODO: Configure TRIS bit for RB2 as input
	
	// Need a pull-up resistor for RB2
	//
	// TODO: Configure CNPU register bits to enable internal pullup resistor for RB2 
	// input.
	
	// Turn LED Off
	LATBbits.LATB15 = 1;
	
	// Initialize State
	state = WaitForPress;
	while(1)
	{
		switch (state) {
			case WaitForPress:
				// Check for button press
				if ( PORTBbits.RB2 == 0 ) {
					state = DebouncePress;
					i = 0;
				}
				break;
				
			case DebouncePress:
				// Wait for some length of time. 
				// THERE IS A BETTER WAY TO DO THIS
				if ( (++i) >= DELAY_AMOUNT ) state = LEDToggle;
				break;
				
			case LEDToggle:
				// Use bit operations on entire port to control LED
				// Why use bit operations? Because we can!!
				LATB = LATB ^ 0x8000;
				
				state = WaitForRelease;
				break;
				
			case WaitForRelease:
				// Check for button release
				if ( PORTBbits.RB2 == 1 ) {
					state = DebounceRelease;
					i = 0;
				}
				break;
				
			case DebounceRelease:
				// Wait for some length of time. 
				// THERE IS A BETTER WAY TO DO THIS
				if ( (++i) >= DELAY_AMOUNT ) state = WaitForPress;
				break;
		}
	}
	return 0;
}

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