MCP4151 digitalpotentiometer

[Björn B. (s2247678)]

hat jemand schon mal den MCP4151 mit SPI angesteuert.Ich hab ein 200k 
Widerstand zwischen MOSI(Atmega32) und SDI/SDO(Mcp4151 bidrektional) 
gesetzt.
Nur empfange ich die gleichen Daten die ich über MOSI(Atmega32) sende an 
dem MISO(Atmega32).(ist auch irgendwie logisch nur steht das so im 
Datenblatt eigentlich müsste ich zumindest meistens 0xFFxx empfangen 
egal bei welcher Adresse+command siehe dazu Datenblatt Seite 48)

Hier mein Quelltext.Ich habs schon mit Software Spi versucht um die 
ersten 6 bits(adresse+command) zu senden und den Rest(SPI string 
Data+Cmderror bit) zu empfangen.Vielleicht kann mir jemand helfen.ICh 
befürchte das geht nur mit Soft SPI.

// Library includes
//#include <avr/io.h>
#include <avr/sleep.h>
#include <compat/deprecated.h>
#include <avr/pgmspace.h>
#include <util/delay.h>
#include <inttypes.h>
#include <avr/interrupt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "Font.h"


#define SELECT_MCP4151 PORTB &= ~(0<<PB4)
#define DESELECT_MCP4151 PORTB |= (1<<PB4)
#define DDR_SPI DDRB
#define DD_SCK  PB7
#define DD_MOSI PB5
#define DD_MISO PB6
#define DD_SS   PB4 






unsigned short read_adc(void);
void SPI_MasterInit(void);
uint8_t SPI_MasterTransmit(char cData);


// Here is the main 
int main (void)
{
unsigned char CharCol_1, CharCol_2, CharCol_3, CharCol_4, CharCol_5;
unsigned char pz, y;
unsigned int pos;
unsigned short test=0x0000;
unsigned char sign;  // setup all pins to outputs
  SPI_MasterInit();
  
  DDRD  = 0xff;
  DDRA  = 0xfe;



PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);


int i=0;
while(i<2)
{i++;
test=read_adc();
}


if (test==0x430F)
sign=0x32;
else sign=0x31;






  if ((sign<0x20) || (sign>0x7F)) { sign = 0x20; } 
  pos = 5*(sign-0x20);

  CharCol_5 = pgm_read_byte(&code5x7[pos++]);
  CharCol_4 = pgm_read_byte(&code5x7[pos++]);
  CharCol_3 = pgm_read_byte(&code5x7[pos++]);
  CharCol_2 = pgm_read_byte(&code5x7[pos++]);
  CharCol_1 = pgm_read_byte(&code5x7[pos++]);

while (1)
{

PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);

if (CharCol_1>0x00)
{
PORTD=(1<<PD2);
PORTA=(!((CharCol_1&0b01000000)>>6)<<PA1)|(!((CharCol_1&0b00100000)>>5)<<PA2)|(!((CharCol_1&0b00010000)>>4)<<PA3)|(!((CharCol_1&0b00001000)>>3)<<PA4)|(!((CharCol_1&0b00000100)>>2)<<PA5)|(!((CharCol_1&0b00000010)>>1)<<PA6)|(!((CharCol_1&0b00000001))<<PA7);

_delay_us(4000);

}

PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);

if (CharCol_2>0x00)
{
PORTD=(1<<PD3);
PORTA=(!((CharCol_2&0b01000000)>>6)<<PA1)|(!((CharCol_2&0b00100000)>>5)<<PA2)|(!((CharCol_2&0b00010000)>>4)<<PA3)|(!((CharCol_2&0b00001000)>>3)<<PA4)|(!((CharCol_2&0b00000100)>>2)<<PA5)|(!((CharCol_2&0b00000010)>>1)<<PA6)|(!((CharCol_2&0b00000001))<<PA7);
_delay_us(4000);


}

PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);



if (CharCol_3>0x00)
{
PORTD=(1<<PD4);
PORTA=(!((CharCol_3&0b01000000)>>6)<<PA1)|(!((CharCol_3&0b00100000)>>5)<<PA2)|(!((CharCol_3&0b00010000)>>4)<<PA3)|(!((CharCol_3&0b00001000)>>3)<<PA4)|(!((CharCol_3&0b00000100)>>2)<<PA5)|(!((CharCol_3&0b00000010)>>1)<<PA6)|(!((CharCol_3&0b00000001))<<PA7);
_delay_us(4000);

}

PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);

if (CharCol_4>0x00)
{
PORTD=(1<<PD5);

PORTA=(!((CharCol_4&0b01000000)>>6)<<PA1)|(!((CharCol_4&0b00100000)>>5)<<PA2)|(!((CharCol_4&0b00010000)>>4)<<PA3)|(!((CharCol_4&0b00001000)>>3)<<PA4)|(!((CharCol_4&0b00000100)>>2)<<PA5)|(!((CharCol_4&0b00000010)>>1)<<PA6)|(!((CharCol_4&0b00000001))<<PA7);


_delay_us(4000);

}

PORTD |= (0<<PD2)|(0<<PD3)|(0<<PD4)|(0<<PD5)|(0<<PD6);


if (CharCol_5>0x00)
{
PORTD=(1<<PD6);
PORTA=(!((CharCol_5&0b01000000)>>6)<<PA1)|(!((CharCol_5&0b00100000)>>5)<<PA2)|(!((CharCol_5&0b00010000)>>4)<<PA3)|(!((CharCol_5&0b00001000)>>3)<<PA4)|(!((CharCol_5&0b00000100)>>2)<<PA5)|(!((CharCol_5&0b00000010)>>1)<<PA6)|(!((CharCol_5&0b00000001))<<PA7);

_delay_us(4000);

}
}
}

void SPI_MasterInit(void)
{volatile char IOReg;
/* Set MOSI and SCK output, all others input */

DDR_SPI =(1<<DD_MOSI)|(1<<DD_SCK)|(1<<DD_SS);


/* Enable SPI, Master, set clock rate fck/16 */
SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR1);
SPSR=(1<<SPI2X);
IOReg=SPSR;                   // clear SPIF bit in SPSR
IOReg=SPDR;

}


uint8_t SPI_MasterTransmit(char cData)
{
/* Start transmission */
SPDR = cData;

/* Wait for transmission complete */
while(!(SPSR & (1<<SPIF)));
return SPDR;
}




unsigned short read_adc(void)
{
  // select ADC wait 100 microseconds then read two bytes
 SELECT_MCP4151;
_delay_us(100);
unsigned char one =SPI_MasterTransmit(0x43);
_delay_us(100); 
unsigned char two = SPI_MasterTransmit(0x0F);
DESELECT_MCP4151;

//move into 16 bit int
 return ((one<<8)|two) ;
}