Description

One potentiometer cross fades 3 LEDs, red, green and blue. A second potentiometer controls the blinking of the LED with the smallest value (from the first pot). 

components Used

• 3 - 220 ohm resistors
• 3 LEDs (red, green, blue)
• wiring
• light bulb for the diffuser
• 2 potentiometers
• arduino board
• breadboard  

 /** Modified code by Clay Shirky <clay.shirky@nyu.edu>for making one potentiometer * control 3 LEDs, red, grn and blue. Added support for a second potentiometer to * control the blinking of the LED with the smallest value. *///pot for fading colorsint potPin = 4; // pot to fade the LEDsint potVal = 0; // store the input from the pot//pot for blinkingint potPinBlink = 5; // pot to blink the LEDint potValBlink = 0; // store the input from the pot//LED placementint redPin = 9;   // Red LED,   connected to digital pin 9int grnPin = 10;  // Green LED, connected to digital pin 10int bluPin = 11;  // Blue LED,  connected to digital pin 11// Program variablesint redVal = 0;   // Variables to store the values to send to the pinsint grnVal = 0;int bluVal = 0;int DEBUG = 1;          // Set to 1 to turn on debugging outputvoid setup(){  pinMode(redPin, OUTPUT);   // sets the pins as output  pinMode(grnPin, OUTPUT);     pinMode(bluPin, OUTPUT);   if (DEBUG) {           // If we want to see the pin values for debugging...    Serial.begin(9600);  // ...set up the serial ouput in 0004 format  }}// Main programvoid loop(){  potVal = analogRead(potPin);   // read the potentiometer (Fade) value at the input pin  potValBlink = analogRead(potPinBlink);   // read the potentiometer (Blink) value at the input pin    if (potVal < 341)  // Lowest third of the potentiometer's range (0-340)  {                      potVal = (potVal * 3) / 4; // Normalize to 0-255    redVal = 256 - potVal;  // Red from full to off    grnVal = potVal;        // Green from off to full    bluVal = 1;             // Blue off        analogWrite(redPin, redVal);   // Write values to LED pins    analogWrite(grnPin, grnVal);     analogWrite(bluPin, bluVal);       delay(potValBlink);    analogWrite(redPin, 0);   // Write values to LED pins    analogWrite(grnPin, grnVal);     analogWrite(bluPin, bluVal);      delay(potValBlink);      }  else if (potVal < 682) // Middle third of potentiometer's range (341-681)  {    potVal = ( (potVal-341) * 3) / 4; // Normalize to 0-255    redVal = 1;            // Red off    grnVal = 256 - potVal; // Green from full to off    bluVal = potVal;       // Blue from off to full        analogWrite(redPin, redVal);   // Write values to LED pins    analogWrite(grnPin, grnVal);     analogWrite(bluPin, bluVal);       delay(potValBlink);    analogWrite(redPin, redVal);   // Write values to LED pins    analogWrite(grnPin, grnVal);     analogWrite(bluPin, 0);      delay(potValBlink);    }  else  // Upper third of potentiometer"s range (682-1023)  {    potVal = ( (potVal-683) * 3) / 4; // Normalize to 0-255    redVal = potVal;       // Red from off to full    grnVal = 1;            // Green off    bluVal = 256 - potVal; // Blue from full to off        analogWrite(redPin, redVal);   // Write values to LED pins    analogWrite(grnPin, grnVal);     analogWrite(bluPin, bluVal);       delay(potValBlink);    analogWrite(redPin, redVal);   // Write values to LED pins    analogWrite(grnPin, 0);     analogWrite(bluPin, bluVal);      delay(potValBlink);        }    //analogWrite(redPin, redVal);   // Write values to LED pins  //analogWrite(grnPin, grnVal);   //analogWrite(bluPin, bluVal);    if (DEBUG) { // If we want to read the output    DEBUG += 1;      // Increment the DEBUG counter    if (DEBUG > 100) // Print every hundred loops    {      DEBUG = 1;     // Reset the counter                             // Serial output using 0004-style functions      Serial.print("R:");    // Indicate that output is red value      Serial.print(redVal);  // Print red value      Serial.print("\t");    // Print a tab      Serial.print("G:");    // Repeat for grn and blu...      Serial.print(grnVal);      Serial.print("\t");          Serial.print("B:");          Serial.println(bluVal); // println, to end with a carriage return    }  }}

Images 

lab3_1

lab3_2