void init_SPI_master (void)
{
	SPI_DDR		|= (1<<SPI_MOSI)|(1<<SPI_SCK);  			//MOSI & SCK are outputs
	CS_CAN_DDR	|= (1<<CS_CAN_PI);							//CS is an output
	RST_CAN_DDR	|= (1<<RST_CAN_PI);						//_RESET is an output
	SPCR     	 = (1<<SPE)|(1<<MSTR)|(1<<SPR0);         	//activate SPI, Set MAster-operationClock divider 16-> SPI at 1 MHZ if oszillator at 16 MHZ
	CS_CAN_PO 	|= (1<<CS_CAN_PI);							//CAN CS->HIGH: MCP disabled
};





unsigned char read_MCP2515_buffer(unsigned char buffer_number)
{	
	
	unsigned char buffer_content[11];

	CS_CAN_PO 	&= ~(1<<CS_CAN_PI);	// MCP enabled
	
	switch (buffer_number)
	{
		case 0: SPDR	= 	0x90; 		// start from byte RXB0SIDH
		case 1: SPDR	= 	0x94;  		// start from byte RXB1SIDH
	};
	
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	buffer_content[0]	=	SPDR;		// RXBnSIDH
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	buffer_content[1] 	= 	SPDR;		// RXBnSIDL
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	buffer_content[2] 	= 	SPDR;		// RXBnEID8, which we won´t save
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	buffer_content[2] 	= 	SPDR;		// RXBnEID0, which we won´t save
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	buffer_content[2] 	= 	SPDR;		// RXBnDLC, number of bytes
	loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send
	
	unsigned char i;
	for (i=0;i<buffer_content[2];i++)
	{
		buffer_content[3+i] 	= 	SPDR;
		loop_until_bit_is_set(SPSR,SPIF);	//	wait until byte was send	
	};
	
	CS_CAN_PO 	|= (1<<CS_CAN_PI);		//  MCP disabled
	
	return(*buffer_content);

};