Published February 3, 2022 © GPL3+

Colour Changing Imp Lamp

The Lincoln Imp held inside an infinity light trap.

BeginnerShowcase (no instructions)137

Things used in this project

Hardware components

Arduino Nano R3

General Purpose Transistor NPN

Resistor 1k ohm

DC/DC Converter, Buck Regulator

Story

1 / 15

For the past years I've been getting back into analogue electronics and electronics project kits like I had as a boy circa 1980, I'd be 9 years old. here's the 150 in 1 kit I had originally(see photos) and the recently acquired 500 in 1 kit with micro-controller (you can see where this is going lol). Ive got quite a collection of them now small AM & FM radio kits, the 130, 150, 300 and 500 in 1 kits. I started building radios then progressed onto LED projects using transistors, 555 timers, comparators and counters to produce coloured effects on RGB led strips.

But I wanted to do more than bulky analogue circuits can do and thats where my dive into Arduino begins. I bought a handful of cheap arduino nano from ebay and set away trying to grasp the basics of C programming (not my forte tbh, I can follow what the sketches read up to a certain point then it becomes muddled lol, depends on program complexity). the sketch used in this project was written by someone else and I tailoured the code to suit my needs.

The code has a number of entries to change the colour on an RGB led including cycling through a color wheel by use of an installed library. see contributor links. I blanked out the code I didnt need and just used the color wheel code set to a 1.5 second wait to switch to the next colour. the result being a slow transition through the spectrum.

I built my own interface circuit to switch 2x LED strips (rough figures: 6 leds per strip, average 80-100mA per colour at full brightness, 250-300mA per strip, results in a 500-600mA total load) from a plug in 230v to 9Vdc power pack (1A rated). 3 x 2n3904 NPN transistor ( or any general perpose type BC547, 2n2222 etc) 3 x 1K resistors from arduino outputs to transistor bases. thats about it, real simple. my led strips are common anode, the transistors switch the negative return from the LEDs. The code sketch includes info on how to use either common anode / cathode LEDs. I used a small buck convertor to give the nano a stable supply and set it to 5.75volts for no reason in particular lol

I fried one Nano when I accidentally connected its power connection to one of the data outputs instead during testing. Nano's dont like it when you do that and they give off a puff of smoke (see photo) so take care and check everything before you power up lol.

Whats with the Imp? Its the Lincoln Imp from LIncoln City, UK. wiki.....

According to a 14th-century legend, two mischievous creatures called imps were sent by Satan to do evil work on Earth. After causing mayhem in Northern England, the two imps headed to Lincoln Cathedral, where they smashed tables and chairs and tripped up the Bishop. When an angel came out of a book of hymns and told them to stop, one of the imps was brave and started throwing rocks at the angel, but the other imp cowered under the broken tables and chairs. The angel turned the first imp to stone, giving the second imp a chance to escape. It is said that even on still days it is always windy around the cathedral, which is the second imp circling the building looking for his friend.

trippin' the Bishop eh? very naughty lol

My Gran had a Brass coal fire set, tongs, brush, and dust pan. This Imp used to be on the brush handle (see photo). the set has long gone and I kept the one remaining Imp safe all this time. now he's sat on top of an infinity mirror, trapped in a cage and glass cover for all time, Muhahahahahaaaa lol. A friend said my lamp looks like a Demonic Valve to fit into a Satanic guitar amplifier. I said yeah it does, if we made another 2 or three of these lamps we could make such an amplifier.

All in all it was a fun project to conceive and build.

Code

RGB led

/*
  RGBLedExample
  Example for the RGBLED Library
  Created by Bret Stateham, November 13, 2014
  You can get the latest version from http://github.com/BretStateham/RGBLED
*/
#include <RGBLED.h>

// Declare an RGBLED instanced named rgbLed
// Red, Green and Blue LED legs are connected to PWM pins 11,9 & 6 respectively
// In this example, we have a COMMON_ANODE LED, use COMMON_CATHODE otherwise
RGBLED rgbLed(11,9,6,COMMON_CATHODE);

//How long to show each color in the example code (in milliseconds);
int delayMs = 50;

void setup() {
  //Initialize Serial communications
  Serial.begin(9600);
  
  //Report the LED type and pins in use to the serial port...
  Serial.println("Welcome to the RGBLED Sample Sketch");
  String ledType = (rgbLed.commonType==0) ? "COMMON_CATHODE" : "COMMON_ANODE";
  Serial.println("Your RGBLED instancse is a " + ledType + " LED");
  Serial.println("And the Red, Green, and Blue legs of the LEDs are connected to pins:");
  Serial.println("r,g,b = " + String(rgbLed.redPin) + "," + String(rgbLed.greenPin) + "," + String(rgbLed.bluePin) );
  Serial.println("");
}

void loop() {

  //The code in the loop shows multiple exampls

  //Set the RGBLED to show RED only
  //printRgbValues() prints various LED values to the Serial port
  //you can monitor the serial port to see the values printed
  //The delay(delayMs) waits for 1 second to be able to see the color shown
  //rgbLed.writeRGB(255,0,0);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show GREEN only
  //rgbLed.writeRGB(0,255,0);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show BLUE only
  //rgbLed.writeRGB(0,0,255);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show YELLOW (RED & GREEN) only
  //rgbLed.writeRGB(255,255,0);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show ORANGE (RED & partial GREEN) only
  //rgbLed.writeRGB(255,128,0);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show PURPLE (RED & BLUE) only
  //rgbLed.writeRGB(255,0,255);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show PINK (RED & partial BLUE) only
  //rgbLed.writeRGB(255,0,128);
  //printRgbValues();
  //delay(delayMs);

  //Set the RGBLED to show a random color
  //rgbLed.writeRandom();
  //printRgbValues();
  //delay(delayMs);
  
  //Set the pins individually if needed
  //rgbLed.writeRed(255);
  //rgbLed.writeGreen(255);
  //rgbLed.writeBlue(255);
  //printRgbValues();
  //delay(delayMs);
  
  //The above code does the same thing as...
  //rgbLed.writeRGB(255,255,255);
  //printRgbValues();
  //delay(delayMs);

  //Show the color wheel
  Serial.println("Showing RGB Color Wheel...");
  Serial.println("------------------------------");
  //Use a 25ms delay between each color in the wheel
  rgbLed.writeColorWheel(1500);

  //Turn off the RGBLED
  //rgbLed.turnOff();
  //printRgbValues();
  //delay(delayMs);

}

//printRgbValues prints the LED pins and values to the serial port
//You can monitor the serial port to see those values
void printRgbValues() {
  Serial.println("Requested RGB Values:");
  Serial.println("(r,g,b)=(" + String(rgbLed.redValue) + "," + String(rgbLed.greenValue) + "," + String(rgbLed.blueValue) + ")");
  Serial.println("Mapped RGB Values based on type (COMMON_ANODE or COMMON_CATHODE):");
  Serial.println("Mapped(r,g,b)=(" + String(rgbLed.redMappedValue) + "," + String(rgbLed.greenMappedValue) + "," + String(rgbLed.blueMappedValue) + ")");
  Serial.println("------------------------------");
}

Colour Changing Imp Lamp

Things used in this project

Hardware components

Story

Schematics

circuit board

Code

RGB led

Credits

petestone

Comments

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Colour Changing Imp Lamp

Colour Changing Imp Lamp

Things used in this project

Hardware components

Story

Schematics

circuit board

Code

RGB led

Credits

petestone

Comments

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