AD5292 mit Arduino SPI Kommunikation

#include <SPI.h>

int resistorPin = A0;   // select the input pin for the potentiometer

int resistanceValue;  // variable to store the value coming from the sensor

const int slaveSelectPin = 10;  // set pin 10 as the slave select for the digital pot

//int COMMAND_1 = 0x0400;   //Write contents of serial data to RDAC; muesste danach die 1024 positionen sein

//int COMMAND_2 = 0x0800;    //Read RDCAC wiper setting from the SDO ouput in the next frame 800 VS 803

//int COMMAND_3 = 0x0C00;    //Store wiper settings

int COMMAND_6 = 0x1802;     //serial data to control register; Table 13 & 14 for details; 1802 or 1803

//int COMMAND_7 =0x1C00;   //read control register from SDO output in next frame

void setup(){

   Serial.begin(9600);  // initialize serial communication at 9600 bits per second

   pinMode (slaveSelectPin, OUTPUT); // set the slaveSelectPin as an output

   // initialize SPI (page 9 in datasheet & http://www.arduino.cc/en/Reference/SPI)

   SPI.setDataMode(SPI_MODE3);               //low clock polarity (low idle) & low phase (falling edge)

   SPI.setBitOrder(MSBFIRST);               //either LSBFIRST or MSBFIRST ; looks like MSB from datasheet

//   SPI.setClockDivider(SPI_CLOCK_DIV16);    //shouldnt matter much here

   SPI.begin();

}

void loop(){

  //change the resistance on this channel from min to max:

  for (int level = 0; level < 1023; level++){

    digitalPotWrite(level); //send info for SPI communication     

    // read out the value from the changed resistance back into the arduino ADC:

    resistanceValue= analogRead(resistorPin);

  } 

}

void digitalPotWrite(int DataBits){

   int new_poti_pos;

   digitalWrite(slaveSelectPin,LOW);   // take the SS pin low to select the chip:

   SPI.transfer(COMMAND_6);                //  allow update of wiper position through digital interface

  delay(200);

   if ( DataBits % 2 ==1){

        new_poti_pos=0x0402;   //Poti position #1

    }

    else{

      new_poti_pos=0x06C2;     //Poti position #2

    }

   SPI.transfer(new_poti_pos);          //send this position to the Poti

   digitalWrite(slaveSelectPin,HIGH);    // take the SS pin high to de-select the chip:

}