1  // I2C Digital Potentiometer
 2  // by Nicholas Zambetti <http://www.zambetti.com>
 3  // and Shawn Bonkowski <http://people.interaction-ivrea.it/s.bonkowski/>
 4  
 5  // Demonstrates use of the Wire library
 6  // Controls AD5171 digital potentiometer via I2C/TWI
 7  
 8  // Created 31 March 2006
 9  
10  // This example code is in the public domain.
11  
12  // This example code is in the public domain.
13  
14  
15  #include <Wire.h>
16  
17  void setup()
18  {
19    Wire.begin(); // join i2c bus (address optional for master)
20  }
21  
22  byte val = 0;
23  
24  void loop()
25  {
26    Wire.beginTransmission(44); // transmit to device #44 (0x2c)
27    // device address is specified in datasheet
28    Wire.write(byte(0x00));            // sends instruction byte
29    Wire.write(val);             // sends potentiometer value byte
30    Wire.endTransmission();     // stop transmitting
31  
32    val++;        // increment value
33    if (val == 64) // if reached 64th position (max)
34    {
35      val = 0;    // start over from lowest value
36    }
37    delay(500);
38  }
39