Description

I modified the Analog Input code found on the Arduino website to have one potentiometer control the blinking rates of two LEDs. In addition, the code has one LED shine at a time, making the LEDs resemble the on and off blinking of christmas lights. (I used green and red lights to enhance this effect.)

Components

• Previous lab setup: green and red LEDs, resistors, breadboard, arduino, yellow and green wires

• Potentiometer with three soldered wires, red yellow and black wires

Code

/*
 * AnalogInput
 * by DojoDave <http://www.0j0.org>
 *
 * Turns on and off a light emitting diode(LED) connected to digital 
 * pin 13. The amount of time the LED will be on and off depends on
 * the value obtained by analogRead(). In the easiest case we connect
 * a potentiometer to analog pin 2.
 *
 * In Jess' modified version the code turns on and off two LEDs connected
 * to digital pins 9 and 11. The potentiometer is connected to analog pin
 * 0.
 */

int potPin = 0;    // select the input pin for the potentiometer
int ledPin1 = 9;   // select the pin for the first LED
int ledPin2 = 11;   // select the pin for the second LED
int val = 0;       // variable to store the value coming from the sensor

void setup() {
  pinMode(ledPin1, OUTPUT);  // declare the ledPin1 as an OUTPUT
  pinMode(ledPin2, OUTPUT);  // declare the ledPin2 as an OUTPUT
}

void loop() {
  val = analogRead(potPin);    // read the value from the sensor
  digitalWrite(ledPin1, HIGH);  // turn the ledPin1 on
  digitalWrite(ledPin2, LOW);  // turn the ledPin2 on
  delay(val);                  // stop the program for some time
  digitalWrite(ledPin1, LOW);   // turn the ledPin off
  digitalWrite(ledPin2, HIGH);   // turn the ledPin off
  delay(val);                  // stop the program for some time
}

Pictures