The AS5048A Magnetic Rotary Encoder reading data with Arduino.

The AS5048A is an easy to use 360° angle position sensor (absolute encoder) with a 14-bit high resolution output and SPI interface. The maximum system accuracy is 0.05° assuming linearization and averaging is done by the external microcontroller.

Please use Diametrically Magnetized Magnets.
like

http://www.amazon.com/Neodymium-Magnets-Disc-Diametrically-Magnetized/dp/B0089FFO68/ref=sr_1_2?ie=UTF8&qid=1361910412&sr=8-2&keywords=Diametrically+magnet

or

[url= http://www.ams.com/eng/Products/Magnetic-Position-Sensors/Magnets3/AS5000-MD6H-3] http://www.ams.com/eng/Products/Magnetic-Position-Sensors/Magnets3/AS5000-MD6H-3[/url]















Tested code:

Code:


#include "SPI.h"
  unsigned int result = 0;
  unsigned int result1 = 0;
  unsigned int result2 = 0;

void setup ()
{
Serial.begin(9600);
SPI.begin();
SPI.setBitOrder(MSBFIRST);
}

void loop () {

digitalWrite(SS, LOW);

  //Reading 8 bit frame (the first half of 16-bit SPI transfer)
  result1 = SPI.transfer(0b00000000);
  Serial.print("byte 1: ");
  Serial.println(result1, BIN);
 
  // removing (masking) first 2 bit
  result1 &= 0b00111111;
  Serial.print("byte 1 masked: ");
  Serial.println(result1, BIN);
 
  //shifting 8 bit to left. to create emty space for last 8 bit transfer
  result1 = result1 << 8;
  Serial.print("byte 1 shifted: ");
  Serial.println(result, BIN);
 
  // getting last 8 bits (the last half of 16-bit SPI transfer)
  result2 = SPI.transfer(0b00000000);
  Serial.print("byte 2: ");
  Serial.println(result2, BIN);
 
  // merging
  result = result1 | result2;
  Serial.print("Result: ");
  Serial.print(result, BIN);
  Serial.print(" = ");
  Serial.println(result, DEC);
  Serial.println();
   
digitalWrite(SS, HIGH);
delay(1000);

}


Serial output:

Code:


byte 1: 10110110
byte 1 masking: 110110
byte 1 shifted: 11011000000000
byte 2: 111010
Result: 11011000111010 = 13882