Reading Data using I2C

[Micro Lover]

hi
i m using 89C2051

i want to read the temperature using i2c in Keil uVision4

is there any simplest code ? // In C

i mean just send address and read data
no more

 

[karthikkrv85]

Hai

Please use this following code

//------------------------------------------------------------------------------
// I2C Functions - Bit Banged
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
// 	Routine:	i2c_start
//	Inputs:		none
//	Outputs:	none
//	Purpose:	Sends I2C Start Trasfer - State "B"
//------------------------------------------------------------------------------
void i2c_start (void)
{
	SDATA = HIGH;							// Set data line high
	SCLK = HIGH;							// Set clock line high
	SDATA = LOW;							// Set data line low (START SIGNAL)
	SCLK = LOW;								// Set clock line low
}

//------------------------------------------------------------------------------
// 	Routine:	i2c_stop
//	Inputs:		none
//	Outputs:	none
//	Purpose:	Sends I2C Stop Trasfer - State "C"
//------------------------------------------------------------------------------
void i2c_stop (void)
{
	unsigned char input_var;

	SCLK = LOW;								// Set clock line low
	SDATA = LOW;							// Set data line low
	SCLK = HIGH;							// Set clock line high
	SDATA = HIGH;							// Set data line high (STOP SIGNAL)
	input_var = SDATA;						// Put port pin into HiZ
}

//------------------------------------------------------------------------------
// 	Routine:	i2c_write
//	Inputs:		output byte
//	Outputs:	none
//	Purpose:	Writes data over the I2C bus
//------------------------------------------------------------------------------
void i2c_write (unsigned char output_data)
{
	unsigned char index;

	for(index = 0; index < 8; index++)  	// Send 8 bits to the I2C Bus
	{
                                 			// Output the data bit to the I2C Bus
		SDATA = ((output_data & 0x80) ? 1 : 0);
      	output_data  <<= 1;            		// Shift the byte by one bit
		SCLK = HIGH;   		        		// Clock the data into the I2C Bus
		SCLK = LOW;					
	}

	index = SDATA;							// Put data pin into read mode
	SCLK = HIGH;   		        			// Clock the ACK from the I2C Bus
	SCLK = LOW;					
}

//------------------------------------------------------------------------------
// 	Routine:	i2c_read
//	Inputs:		none
//	Outputs:	input byte
//	Purpose:	Reads data from the I2C bus
//------------------------------------------------------------------------------
unsigned char i2c_read (void)
{
	unsigned char index, input_data;

   	index = SDATA;							// Put data pin into read mode

	input_data = 0x00;
	for(index = 0; index < 8; index++)  	// Send 8 bits to the I2C Bus
	{
		input_data <<= 1;					// Shift the byte by one bit
		SCLK = HIGH;           				// Clock the data into the I2C Bus
      	input_data |= SDATA; 		   		// Input the data from the I2C Bus
		SCLK = LOW;					
	}

   return input_data;
}

I hope you will be knowing how to assign the port pins to the SDA and SCL and also the transferring ways

All the best