How to use a digital potenciometer with Arduino (MCP 4131-103)

digital_pot.ino

/*
 * How to use a digital potenciometer with Arduino
 * Link to article: https://www.gsampallo.com/?p=952
 */
#include <SPI.h>

byte address = 0x00;
int CS = 10;

void setup() {
    pinMode (CS, OUTPUT);
    SPI.begin();
}

void loop() {
  for (int i = 0; i <= 128; i++) {
    digitalPotWrite(i);
    delay(10);
  }
  delay(500);
  for (int i = 128; i >= 0; i--) {
    digitalPotWrite(i);
    delay(10);
  }
}

int digitalPotWrite(int value) {
  digitalWrite(CS, LOW);
  SPI.transfer(address);
  SPI.transfer(value);
  digitalWrite(CS, HIGH);
}