Assignment: Sensing: Potentiometers

Collaborators:

Description

Use two potentiometers to control blinking speed and brightness. For the optional part, I made one pot control blinking speed and one to control a cycle of colors.

Components Used

• 3  LEDs
• 3 220 Resistors
• Diffuser (opaque white bottle stuffed with tissue)
• 2 Potentiometers

Arduino Code

For the first part, I used the code for 2 pots on the course website. For the optional portion, I used this code:

/*
 * Modification of the blinking and fading program from class.
 * Here, one pot controls blinking, while the other cycles
 * through colors.
 */
int colorPot = 0;
int blinkPot = 1;
int colorPotVal = 0;
int blinkPotVal = 0;
int redPin = 9;
int greenPin = 10;
int bluePin = 11;
int redVal = 255;
int greenVal = 1;
int blueVal = 1;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  colorPotVal = analogRead(colorPot);   // read the value from pot 1, between 0 - 1024, for dimming
  blinkPotVal = analogRead(blinkPot);   // read the value from pot 2, between 0 - 1024, for blinking
  displayColor(colorPotVal);
  delay(blinkPotVal);                  // stop the program for some time, meaning, LED is on for this time
  blinkOff();
  delay(blinkPotVal);                  // stop the program for some time, meaning, LED is OFF for this time
}

void displayColor(int colorPotVal) {
  if (colorPotVal < 256) {
    redVal = 255 - colorPotVal;
    greenVal = colorPotVal;
    analogWrite(redPin, redVal);
    analogWrite(greenPin, greenVal);
  } else if (colorPotVal < 512) {
    greenVal = 511 - colorPotVal;
    blueVal = colorPotVal - 256;
    analogWrite(greenPin, greenVal);
    analogWrite(bluePin, blueVal);
  } else if (colorPotVal < 768) {
    blueVal = 767 - colorPotVal;
    redVal = colorPotVal - 512;
    analogWrite(bluePin, blueVal);
    analogWrite(redPin, redVal);
  } else if (colorPotVal < 1024) {
    greenVal = 1023 - colorPotVal;
    blueVal = colorPotVal - 768;
    analogWrite(redPin, 255);
    analogWrite(greenPin, greenVal);
    analogWrite(bluePin, blueVal);
  }
}

// turns off all the LEDs
void blinkOff() {
  analogWrite(redPin, 0);
  analogWrite(greenPin, 0);
  analogWrite(bluePin, 0);
}

Item

Video showing one pot controlling color cycle: