// ******************************************************************************************* //
//
// Author: Roman Lysecky
// Date: November 18, 2010
//
// Basic set of software routines for accessing the ADLX345 acclerometer using an SPI 
// interface.
// 
// NOTE: This library of routine is incompelte, and only supports a small subset of 
// commands.
//
// ******************************************************************************************* //

#include "p24fj64ga002.h"
#include "libpic30.h"
#include "stdio.h"

// ******************************************************************************************* //
// Configuration bits for CONFIG1 and CONFIG2. 
//
// 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_OFF & ICS_PGx1 & 
		  FWDTEN_OFF & WINDIS_OFF & FWPSA_PR128 & WDTPS_PS32768 )

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

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

// Allocates an array of integers in program memory that we will use to persistenyly store data 
// even in the baence of power to the PIC. The space(prog) indicates the aray wil be located in
// program memory. The size of the aray should be equal to one FLASH page, as we can only update 
// one FLASH_PAGE at a time with the PIC24F. In addition, the aligned(_FLASH_PAGE*2)
// ensure the array is properly aligned at a FLASH_PAGE boundary.

int __attribute__((space(prog), aligned(_FLASH_PAGE*2))) flash_data[_FLASH_PAGE];

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

#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)

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

#define BAUDRATE  115200       
#define BRGVAL    ((FCY/BAUDRATE)/16)-1 

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

volatile int updateCount = 0;

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

int main(void)
{
	int count = 0;
	
	// local array (i.e. array stored in data memory) used for data storage with a size equal 
	// to one FLASH page (i.e. _FLASH_PAGE integers).
	int local_data[_FLASH_PAGE];
	
	// Data structure that acts as a pointer to a program address.
	_prog_addressT flash_data_p;  
	
	// ******************************************************************************* //
	// UART1 is used debugging through printf's
	// ******************************************************************************* //
	
	RPINR18bits.U1RXR = 9;	// UART1 RX connected to RP9
	RPOR4bits.RP8R = 3;		// UART1 TX connected to RP8
	U1BRG  = BRGVAL;        // Set UART1's baud rate generator register
	U1MODE = 0x8000; 	    // UART enabled, 8-bit, 1 stop bit, no parity	
	U1STA  = 0x0440; 		// UART TX enabled, U1RXIF set when any character received 
	
	// ******************************************************************************* //
	
	_TRISB5 = 1;
	_CN27IE = 1;   
	_CNIF = 0;
	_CNIE = 1;
	
	// ******************************************************************************* //
	
	// Get program address for flash_data array.
	_init_prog_address(flash_data_p, flash_data);
	
	// Copy data from program memory to the local data array. The size of the transfer
	// for one flash page is _FLASH_PAGE*2 (i.e. specified in bytes not 16-bit words).
	_memcpy_p2d16(local_data, flash_data_p, _FLASH_PAGE*2);
	
	// Retrieve the last count value, and print the count to the UART
	count = local_data[0];
	printf("init count = %i\r\n", count);
	
	// ******************************************************************************* //
	
	while(1)
	{	
		if( updateCount == 1 ) {
			updateCount = 0;
			count++;
			printf("%i\r\n", count);
			
			// Write the update count value to the local data array. 			
			local_data[0] = count;
			
			// Erase the FLASH page where we will store the data in program memory.
			// NOTE: You must erase the FLASH page before writing.
			_erase_flash(flash_data_p);
			
			// Write the local data array to the program memory.
			_write_flash16(flash_data_p, local_data);
		}	
	}
	
	return 0;
}

// ******************************************************************************************* //
// Change Notifcation interrupt use to detect if SW5 (connected to RB5) of the Starter Board 
// is pressed, and set the updateCount variable used within the main execution loop.
// ******************************************************************************************* //
void _ISR _CNInterrupt(void)
{	
	_CNIF = 0; // Clear the change notification interrupt flag 
	
	// If button pressed, set updateCount variable.
	if ( _RB5 == 0 ) {
 		updateCount = 1;
	}
}

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