// ******************************************************************************************* //
// 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 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 I2CSCLRATE 400000
#define I2CBRGVAL  ((FCY/I2CSCLRATE)-(FCY/10000000))-1

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

#define TMP102_ADDR      0x90
#define TMP102_TEMPREG   0x00

// ******************************************************************************************* //
//
// Initialize I2C component and TMP102 sensor for reading temperature values. This function
// will configure the pointer register within the TMP102 sensor to the address for reading 
// the temperature

void TMP102Initialize() 
{

	// Configure I2C component for PIC24F
	// TODO: Configure I2C baud rate generator register (I2C1BRG)	
	// TODO: Enable I2C
	// TODO: Configure SMEN bit if SMBus voltage levels are used
	// TODO: Clear Master I2C interrupt flag (MI2C1IF)

	// TODO: Send start by setting SEN to 1, wait for interrupt, clear interrupt flag
		
	// Write to TMP102 Temperature Register to set the Pointer Register by
	// 1. Writing device address and write command to I2C transmit registers (I2C1TRN), 
	// wait for interrupt, clear interrupt
	I2C1TRN = TMP102_ADDR | 0x00; while(IFS1bits.MI2C1IF==0); IFS1bits.MI2C1IF=0;		

	// 2. Write value for pointer register within TMP102 sensor, wait for interrupt, 
	// clear interrupt flag
	I2C1TRN = TMP102_TEMPREG; while(IFS1bits.MI2C1IF==0); IFS1bits.MI2C1IF=0;	
			
	// TODO: Send stop by asserting PEN to 1, wait for interrupt, clear interrupt flag
}
	
// ******************************************************************************************* //
//
// Reads 12-bit temperature value from TMP102 sensor as a 16-bit value using the I2C component
// and returns the temperature in Fahrenheit.
//
// NOTE: The value read directly from the temperature sensor is in Celsius, and needs to be
// converted to Fahrenheit.

int TMP102GetTemperature()
{
	long int temperature;

	// TODO: Send start by setting SEN to 1, wait for interrupt, clear interrupt flag
		
	// TODO: Writing device address and read command to I2C transmit registers (I2C1TRN), 
	// wait for interrupt, clear interrupt

	// TODO: Start I2C receive by setting RCEN to 1, wait for interrupt, clear interrupt flag

	// Received byte is stored within I2C receive register (I2C1RCV)
	temperature = ((unsigned long int)I2C1RCV << 8);
		
	// TODO: Send acknowledge by setting ACKEN to 1, wait for interrupt, clear interrupt flag
			
	// TODO: Start I2C receive by setting RCEN to 1, wait for interrupt, clear interrupt flag
	
	// Received byte is stored within I2C receive register (I2C1RCV)
	temperature = temperature | I2C1RCV;
		
	// TODO: Send acknowledge by setting ACKEN to 1, wait for interrupt, clear interrupt flag
		
	// TODO: Send stop by asserting PEN to 1, wait for interrupt, clear interrupt flag
	
	// TODO: Convert temperature to Fahrenheit
	
	// Return temperature reading.
	return temperature;
}
	
// ******************************************************************************************* //