#include <REG515C.H>

sbit iic_clk  = P3^3;
sbit iic_data = P3^5;
sbit ack_test = P4^0;

unsigned char daten_bits = 8;
unsigned char sensor_adr_read  = 0x29 ;
unsigned char sensor_adr_write = 0x29 ;


void zeit (void)
{
	;
}

void iic_start (void)
{
	iic_data = 1;
	iic_clk = 1;
	iic_data = 0;
	iic_clk = 0;
}


void iic_stop (void)
{
	iic_data = 0;	
	iic_clk = 1;
	iic_data = 1;
}



bit transmit_data (unsigned char daten)
{
	unsigned char i;

	for ( i = 0 ; i < daten_bits ; i++)
	{
		daten = daten << 1;
		if ( CY == 1 )
		{
			iic_data = 1;
		}
		else
		{
			iic_data = 0;
		}
		iic_clk = 1;
		iic_clk = 0;
	}

	iic_data = 1;
	iic_clk = 1;
	i = iic_data;
	iic_clk = 0;

	return i;
}


unsigned char receive_data (bit ack)
{
	unsigned char i,daten=0;
	i = iic_data;
	
	for ( i=0 ; i < daten_bits ; i++)
	{
		if ( iic_data == 1)
		{
			daten = daten | 0x01;
		}
		iic_clk = 1;
		daten = daten << 1;
		iic_clk = 0;	
	}

	if (ack)
	{
		iic_data = 0;
	}
	else
	{
		iic_data = 1;
	}

	iic_clk = 1;
	iic_clk = 0;
	iic_data = 0;

	return daten ;
}


void startup_sensor(void)
{
		iic_start();				// i2c Start
	    	transmit_data(sensor_adr_write);		// Schreibanforderung an Adresse 0x29h
		transmit_data(0xD0);			// Command Reg -> CMD=1;CLEAR=1;BLOCK=1;Reg Adresse 0h = Control Reg
//		transmit_data(0x00);    			// Count N Byte -> wird benötigt aber nicht gewertet
		transmit_data(0x03);			// Control Reg auf 0x03 setzten -> POWER UP
		iic_stop();				// i2c Stop

		zeit();
		zeit();
	
		iic_start();				// i2c Start
		transmit_data(sensor_adr_write);		// Schreibanforderung an Adresse 0x29h
		transmit_data(0xD1);			// Command Reg -> CMD=1;CLEAR=1;BLOCK=1;Reg Adresse 1h = Timing Reg
//		transmit_data(0x00);    			// Count N Byte -> wird benötigt aber nicht gewertet
		transmit_data(0x02);			// Timing Reg auf 0x10 setzten -> GAIN 16x, Int Time 13,7ms
		iic_stop();				// i2c Stop
	
}

main()
{
	 unsigned int i=0;
	 
	 unsigned char daten_high = 0;
	 unsigned char daten_low = 0;
	 unsigned long ad_0 = 0;
	
	while (1)
	{

		startup_sensor();
	
		iic_start();						// i2c Start
		transmit_data(sensor_adr_write);				// Schreibanforderung an Adresse 0x28h
		transmit_data(0xDC);					// Command Reg -> CMD=1;CLEAR=1;BLOCK=1;Reg Adresse Ch = ADC CH0 low
		iic_start();						
	   	transmit_data(sensor_adr_read);    
		receive_data(1);
		daten_low = receive_data(0);
		iic_stop();						//i2c Stop

		iic_start();						// i2c Start
		transmit_data(sensor_adr_write);				// Schreibanforderung an Adresse 0x28h
		transmit_data(0xDD);					// Command Reg -> CMD=1;CLEAR=1;BLOCK=1;Reg Adresse Ch = ADC CH0 high
		iic_start();
	    	transmit_data(sensor_adr_read);    
		receive_data(1);
		daten_high = receive_data(0);
		iic_stop();						//i2c Stop
	
		ad_0 =  daten_high << 8|daten_low  ;

		P5 = daten_low;		
	}
}