//--- I2C driver--------------------------------
//PIC 16 F877A
//
// 19.12.2017 P. Viljakainen
//-----------------------------------------------

#include <htc.h>
#include <stdlib.h>
//#include "math.h"
//#include "i2c.h"
//#include "saa1064.h"
//#include "delays.h"


//Function: I2CInit
//Return:
//Arguments:
//Description: Initialize I2C in master mode, Sets the required baudrate

void I2CInit(void)
{
	TRISC3 = 1;      // SDA and SCL as input pin 
	TRISC4 = 1;      // these pins can be configured either i/p or o/p 
	SSPSTAT |= 0x80; // Slew rate disabled 
	SSPCON1 =0x28;	// SSPEN = 1, I2C Master mode, clock = FOSC/(4 * (SSPADD + 1))
	//SSPCON2 28;    
	SSPADD = 0x28;    // 100Khz @ 4Mhz Fosc 
}



//Function: I2CStart
//Return:
//Arguments:
//Description: Send a start condition on I2C Bus

void I2CStart(void)
{
	SEN = 1;         // Start condition enabled 
	while(SEN);      // automatically cleared by hardware 
                     // wait for start condition to finish 
}
 

//Function: I2CStop
//Return:
//Arguments:
//Description: Send a stop condition on I2C Bus

void I2CStop(void)
{
	PEN = 1;         // Stop condition enabled 
	while(PEN);      // Wait for stop condition to finish 
                     // PEN automatically cleared by hardware 
}
 

//Function: I2CRestart
//Return:
//Arguments:
//Description: Sends a repeated start condition on I2C Bus

void I2CRestart(void)
{
	RSEN = 1;        // Repeated start enabled 
	while(RSEN);     // wait for condition to finish 
}
 

//Function: I2CAck
//Return:
//Arguments:
//Description: Generates acknowledge for a transfer

void I2CAck(void)
{
	ACKDT = 0;       // Acknowledge data bit, 0 = ACK 
	ACKEN = 1;       // Ack data enabled */
	while(ACKEN);    // wait for ack data to send on bus 
}
 

//Function: I2CNck
//Return:
//Arguments:
//Description: Generates Not-acknowledge for a transfer

void I2CNak(void)
{
	ACKDT = 1;       // Acknowledge data bit, 1 = NAK 
	ACKEN = 1;       // Ack data enabled 
	while(ACKEN);    // wait for ack data to send on bus 
}
 

//Function: I2CWait
//Return:
//Arguments:
//Description: wait for transfer to finish

void I2CWait(void)
{
	while ((SSPCON2 & 0x1F ) || ( SSPSTAT &0x04 ) );
		// wait for any pending transfer
}
 

//Function: I2CSend
//Return:
//Arguments: dat - 8-bit data to be sent on bus
//           data can be either address/data byte
//Description: Send 8-bit data on I2C bus

void I2CSend(unsigned char dat)
{
	SSPBUF = dat;    //Move data to SSPBUF 
	while(BF);       // wait till complete data is sent from buffer 
	I2CWait();       // wait for any pending transfer 
}
 

//Function: I2CRead
//Return:    8-bit data read from I2C bus
//Arguments:
//Description: read 8-bit data from I2C bus

unsigned char I2CRead(void)

{
	unsigned char temp;//Reception works if transfer is initiated in read mode					 
	RCEN = 1;        // Enable data reception 
	while(!BF);      // wait for buffer full 
	temp = SSPBUF;   // Read serial buffer and store in temp register 
	I2CWait();       // wait to check any pending transfer 
	return temp;     //( Return the read data from bus 
}