Tutorial.DimmingLEDs History

Hide minor edits - Show changes to output

April 28, 2006, at 06:08 PM by Clay Shirky -
Changed line 30 from:
Serial.begin(9600); // ...set up the serial ouput
to:
Serial.begin(9600); // ...set up the serial ouput on 0004 style
Changed line 71 from:
Serial.print(i);
to:
Serial.print(i); // Serial commands in 0004 style
April 28, 2006, at 06:07 PM by Clay Shirky - Noted that the debugging code assumes 0004
Added line 6:
* The debugging code assumes Arduino 0004, as it uses the new Serial.begin()-style functions
April 18, 2006, at 08:45 PM by Clay Shirky - PWM example using timer
Added line 2:
Changed lines 4-5 from:
* Code for making one potentiometer control 3 LEDs, red, green and blue, or one tri-color LED
* The program cross-fades from red to green, green to blue, and blue to red
to:
* Code for cross-fading 3 LEDs, red, green and blue, or one tri-color LED, using PWM
* The program cross-fades slowly from red to green, green to blue, and blue to red
Changed lines 9-14 from:
// INPUT: Potentiometer should be connected to 5V and GND
int potPin = 3; // Potentiometer output connected to analog pin 3
int potVal = 0; // Variable to store the input from the potentiometer

// OUTPUT: Use digital pins 9-11, the Pulse-width Modulation (PWM) pins
// LED's cathodes should be connected to digital GND
to:
// Output
Changed lines 15-20 from:
int redVal = 0; // Variables to store the values to send to the pins
int greenVal = 0;
int blueVal = 0;

int DEBUG = 1; // Set to 1 to turn on debugging output
to:
int redVal = 255; // Variables to store the values to send to the pins
int greenVal = 1; // Initial values are Red full, Green and Blue off
int blueVal = 1;

int i = 0; // Loop counter
int wait = 50; // 50ms (.05 second) delay; shorten for faster fades
int DEBUG = 0; // DEBUG counter; if set to 1, will write values back via serial
Changed lines 36-46 from:
potVal = analogRead(potPin); // read the potentiometer value at the input pin

if (potVal < 342) // Lowest third of the potentiometer's range (0-341)
{
potVal = (potVal * 3) / 4; // Normalize to 0-255

redVal = 255 - potVal; // Red from full to zero
greenVal = potVal; // Green from zero to full
blueVal = 0; // Blue off
}
else if (potVal < 683) // Middle third of potentiometer's range (342-682)
to:
i += 1; // Increment counter
if (i < 255) // First phase of fades
Changed lines 39-43 from:
potVal = ( (potVal-341) * 3) / 4; // Normalize to 0-255

redVal = 0; // Red off
greenVal = 255 - potVal; // Green from full to zero
blueVal = potVal; // Blue from zero to full
to:
redVal -= 1; // Red down
greenVal += 1; // Green up
blueVal = 1; // Blue low
Changed line 43 from:
else // Upper third of potentiometer"s range (683-1023)
to:
else if (i < 509) // Second phase of fades
Changed lines 45-49 from:
potVal = ( (potVal-682) * 3) / 4; // Normalize to 0-255

redVal = potVal; // Red from zero to full
greenVal = 0; // Green off
blueVal = 255 - potVal; // Blue from full to zero
to:
redVal = 1; // Red low
greenVal -= 1; // Green down
blueVal += 1; // Blue up
}
else if (i < 763) // Third phase of fades
{
redVal += 1; // Red up
greenVal = 1; // Green low
blueVal -= 1; // Blue down
Changed lines 55-60 from:
analogWrite(redPin, redVal); // Write values to LED pins
to:
else // Re-set the counter, and start the fades again
{
i = 1;
}

analogWrite(redPin, redVal); // Write current values to LED pins
Changed lines 65-66 from:
DEBUG += 1; // Increment the DEBUG counter
if (DEBUG > 100) // Print every hundred loops
to:
DEBUG += 1; // Increment the DEBUG counter
if (DEBUG > 10) // Print every 10 loops
Added lines 70-71:
Serial.print(i);
Serial.print("\t"); // Print a tab
Added line 82:
delay(wait); // Pause for 'wait' milliseconds before resuming the loop
Changed lines 84-85 from:
@]
to:
@]
April 18, 2006, at 05:27 PM by Clay Shirky -
Changed line 12 from:
// OUTPUT, using digital pins 9-11, the Pulse-width Modulation (PWM) pins
to:
// OUTPUT: Use digital pins 9-11, the Pulse-width Modulation (PWM) pins
April 18, 2006, at 05:27 PM by Clay Shirky -
Changed lines 8-9 from:
// INPUT
int potPin = 3; // Potentiometer connected to analog pin 3
to:
// INPUT: Potentiometer should be connected to 5V and GND
int potPin = 3; // Potentiometer output connected to analog pin 3
Added line 13:
// LED's cathodes should be connected to digital GND
April 18, 2006, at 05:21 PM by Clay Shirky -
Changed line 12 from:
// Output
to:
// OUTPUT, using digital pins 9-11, the Pulse-width Modulation (PWM) pins
April 18, 2006, at 05:19 PM by Clay Shirky -
Added lines 1-84:
[@
/*
* Code for making one potentiometer control 3 LEDs, red, green and blue, or one tri-color LED
* The program cross-fades from red to green, green to blue, and blue to red
* Clay Shirky <clay.shirky@nyu.edu>
*/

// INPUT
int potPin = 3; // Potentiometer connected to analog pin 3
int potVal = 0; // Variable to store the input from the potentiometer

// Output
int redPin = 9; // Red LED, connected to digital pin 9
int greenPin = 10; // Green LED, connected to digital pin 10
int bluePin = 11; // Blue LED, connected to digital pin 11

// Program variables
int redVal = 0; // Variables to store the values to send to the pins
int greenVal = 0;
int blueVal = 0;

int DEBUG = 1; // Set to 1 to turn on debugging output

void setup()
{
pinMode(redPin, OUTPUT); // sets the pins as output
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
if (DEBUG) { // If we want to see the pin values for debugging...
Serial.begin(9600); // ...set up the serial ouput
}
}

// Main program
void loop()
{
potVal = analogRead(potPin); // read the potentiometer value at the input pin

if (potVal < 342) // Lowest third of the potentiometer's range (0-341)
{
potVal = (potVal * 3) / 4; // Normalize to 0-255

redVal = 255 - potVal; // Red from full to zero
greenVal = potVal; // Green from zero to full
blueVal = 0; // Blue off
}
else if (potVal < 683) // Middle third of potentiometer's range (342-682)
{
potVal = ( (potVal-341) * 3) / 4; // Normalize to 0-255

redVal = 0; // Red off
greenVal = 255 - potVal; // Green from full to zero
blueVal = potVal; // Blue from zero to full
}
else // Upper third of potentiometer"s range (683-1023)
{
potVal = ( (potVal-682) * 3) / 4; // Normalize to 0-255

redVal = potVal; // Red from zero to full
greenVal = 0; // Green off
blueVal = 255 - potVal; // Blue from full to zero
}
analogWrite(redPin, redVal); // Write values to LED pins
analogWrite(greenPin, greenVal);
analogWrite(bluePin, blueVal);

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.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 green and blue...
Serial.print(greenVal);
Serial.print("\t");
Serial.print("B:");
Serial.println(blueVal); // println, to end with a carriage return
}
}
}
@]

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