AS5140 as incremental encoder

Wiring for incremental mode is shown below:

Arduino code:

/*
This sketch was developed buy Ing. Dmitry Kochubey
in Technical university of Liberec
Czech Republic
year 2013
*/

#define ENCODER_A_PIN 2
#define ENCODER_B_PIN 3

long pos = 0;

void setup()
{
   pinMode(ENCODER_A_PIN, INPUT);
   pinMode(ENCODER_B_PIN, INPUT);

   attachInterrupt(0, read_quadrature, CHANGE);
  
   Serial.begin(9600);
}

void loop()
{
   Serial.print("Position: ");
   Serial.println(pos, DEC);
   delay(1000);
}

void read_quadrature()
{ 
  // found a low-to-high on channel A
  if (digitalRead(ENCODER_A_PIN) == HIGH)
  {  
    // check channel B to see which way
    if (digitalRead(ENCODER_B_PIN) == LOW)
        pos++;
    else
        pos--;
  }
  // found a high-to-low on channel A
  else                                       
  {
    // check channel B to see which way
    if (digitalRead(ENCODER_B_PIN) == LOW)
        pos--;
    else
        pos++;
  }
}

Enjoy!