Posts with «strip» label

Experimenting with Arduino and IKEA DIODER LED Strips

Introduction

A few weeks ago I found a DIODER LED strip set from a long-ago trek to IKEA, and considered that something could be done with it.  So in this article you can see how easy it is to control the LEDs using an Arduino or compatible board with ease… opening it up to all sorts of possibilities.

This is not the most original project – however things have been pretty quiet around here, so I thought it was time to share something new with you. Furthermore the DIODER control PCB has changed, so this will be relevant to new purchases. Nevertheless, let’s get on with it.

So what is DIODER anyhow? 

As you can see in the image below, the DIODER pack includes four RGB LED units each with nine RGB LEDs per unit. A controller box allows power and colour choice, a distribution box connects between the controller box and the LED strips, and the whole thing is powered by a 12V DC plugpack:

The following is a quick video showing the DIODER in action as devised by IKEA:

 

Thankfully the plugpack keeps us away from mains voltages, and includes a long detachable cable which connects to the LED strip distribution box. The first thought was to investigate the controller, and you can open it with a standard screwdriver. Carefully pry away the long-side, as two clips on each side hold it together…


… which reveals the PCB. Nothing too exciting here – you can see the potentiometer used for changing the lighting effects, power and range buttons and so on:

Our DIODER has the updated PCB with the Chinese market microcontroller. If you have an older DIODER with a Microchip PIC – you can reprogram it yourself.

The following three MOSFETs are used to control the current to each of the red, green and blue LED circuits. These will be the key to controlling the DIODER’s strips – but are way too small for me to solder to. The original plan was to have an Arduino’s PWM outputs tap into the MOSFET’s gates – but instead I will use external MOSFETs.

So what’s a MOSFET?

In the past you may have used a transistor to switch higher current from an Arduino, however a MOSFET is a better solution for this function. The can control large voltages and high currents without any effort. We will use N-channel MOSFETs, which have three pins – Source, Drain and Gate. When the Gate is HIGH, current will flow into the Drain and out of the Gate:

A simplistic explanation is that it can be used like a button – and when wiring your own N-MOSFET a 10k resistor should be used between Gate and Drain to keep the Gate low when the Arduino output is set to LOW (just like de-bouncing a button). To learn more about MOSFETS – get yourself a copy of “The Art of Electronics“. It is worth every cent.

However being somewhat time poor (lazy?), I have instead used a Freetronics NDrive Shield for Arduino – which contains six N-MOSFETs all on one convenient shield  – with each MOSFET’s Gate pin connected to an Arduino PWM output.

So let’s head back to the LED strips for a moment, in order to determine how the LEDs are wired in the strip. Thanks to the manufacturer – the PCB has the markings as shown below:

They’re 12V LEDs in a common-anode configuration. How much current do they draw? Depends on how many strips you have connected together…

For the curious I measured each colour at each length, with the results in the following table:

So all four strips turned on, with all colours on – the strips will draw around 165 mA of current at 12V. Those blue LEDs are certainly thirsty.

Moving on, the next step is to connect the strips to the MOSFET shield. This is easy thanks to the cable included in the DIODER pack, just chop the white connector off as shown below:

By connecting an LED strip to the other end of the cable you can then determine which wire is common, and which are the cathodes for red, green and blue.

The plugpack included with the DIODER pack can be used to power the entire project, so you will need cut the DC plug (the plug that connects into the DIODER’s distribution box) off the lead, and use a multimeter to determine which wire is negative, and which is positive.

Connect the negative wire to the GND terminal on the shield, and the positive wire to the Vin terminal.  Then…

  • the red LED wire to the D3 terminal,
  • the green LED wire to the D9 terminal,
  • and the blue LED wire to the D10 terminal.

Finally, connect the 12V LED wire (anode) into the Vin terminal. Now double-check your wiring. Then check it again.

Testing

Now to run a test sketch to show the LED strip can easily be controlled. We’ll turn each colour on and off using PWM (Pulse-Width Modulation) – a neat way to control the brightness of each colour. The following sketch will pulse each colour in turn, and there’s also a blink function you can use.

// Controlling IKEA DIODER LED strips with Arduino and Freetronics NDRIVE N-MOSFET shield
// CC by-sa-nc John Boxall 2015 - tronixstuff.com 
// Components from tronixlabs.com

#define red 3
#define green 9
#define blue 10
#define delaya 2

void setup() 
{
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(blue, OUTPUT);
}

void blinkRGB()
{
  digitalWrite(red, HIGH);
  delay(1000);
  digitalWrite(red, LOW);
  digitalWrite(green, HIGH);
  delay(1000);
  digitalWrite(green, LOW);
  digitalWrite(blue, HIGH);
  delay(1000);
  digitalWrite(blue, LOW);
}

void pulseRed()
{
  for (int i=0; i<256; i++)
  {
    analogWrite(red,i);
    delay(delaya);
  }
  for (int i=255; i>=0; --i)
  {
    analogWrite(red,i);
    delay(delaya);
  }
}

void pulseGreen()
{
  for (int i=0; i<256; i++)
  {
    analogWrite(green,i);
    delay(delaya);
  }
  for (int i=255; i>=0; --i)
  {
    analogWrite(green,i);
    delay(delaya);
  }
}

void pulseBlue()
{
  for (int i=0; i<256; i++)
  {
    analogWrite(blue,i);
    delay(delaya);
  }
  for (int i=255; i>=0; --i)
  {
    analogWrite(blue,i);
    delay(delaya);
  }
}

void loop()
{
  pulseRed();
  pulseGreen();
  pulseBlue();
}

Success. And for the non-believers, watch the following video:

Better LED control

As always, there’s a better way of doing things and one example of LED control is the awesome FASTLED library by Daniel Garcia and others. Go and download it now – https://github.com/FastLED/FastLED. Apart from our simple LEDS, the FASTLED library is also great with WS2812B/Adafruit NeoPixels and others.

One excellent demonstration included with the library is the AnalogOutput sketch, which I have supplied below to work with our example hardware:

#include <FastLED.h>

// Example showing how to use FastLED color functions
// even when you're NOT using a "pixel-addressible" smart LED strip.
//
// This example is designed to control an "analog" RGB LED strip
// (or a single RGB LED) being driven by Arduino PWM output pins.
// So this code never calls FastLED.addLEDs() or FastLED.show().
//
// This example illustrates one way you can use just the portions 
// of FastLED that you need.  In this case, this code uses just the
// fast HSV color conversion code.
// 
// In this example, the RGB values are output on three separate
// 'analog' PWM pins, one for red, one for green, and one for blue.
 
#define REDPIN   3
#define GREENPIN 9
#define BLUEPIN  10

// showAnalogRGB: this is like FastLED.show(), but outputs on 
// analog PWM output pins instead of sending data to an intelligent,
// pixel-addressable LED strip.
// 
// This function takes the incoming RGB values and outputs the values
// on three analog PWM output pins to the r, g, and b values respectively.
void showAnalogRGB( const CRGB& rgb)
{
  analogWrite(REDPIN,   rgb.r );
  analogWrite(GREENPIN, rgb.g );
  analogWrite(BLUEPIN,  rgb.b );
}



// colorBars: flashes Red, then Green, then Blue, then Black.
// Helpful for diagnosing if you've mis-wired which is which.
void colorBars()
{
  showAnalogRGB( CRGB::Red );   delay(500);
  showAnalogRGB( CRGB::Green ); delay(500);
  showAnalogRGB( CRGB::Blue );  delay(500);
  showAnalogRGB( CRGB::Black ); delay(500);
}

void loop() 
{
  static uint8_t hue;
  hue = hue + 1;
  // Use FastLED automatic HSV->RGB conversion
  showAnalogRGB( CHSV( hue, 255, 255) );
  
  delay(20);
}


void setup() {
  pinMode(REDPIN,   OUTPUT);
  pinMode(GREENPIN, OUTPUT);
  pinMode(BLUEPIN,  OUTPUT);

  // Flash the "hello" color sequence: R, G, B, black.
  colorBars();
}

You can see this in action through the following video:

Conclusion

So if you have some IKEA LED strips, or anything else that requires more current than an Arduino’s output pin can offer – you can use MOSFETs to take over the current control and have fun. And finally a plug for my own store – tronixlabs.com – offering a growing range and Australia’s best value for supported hobbyist electronics from adafruit, DFRobot, Freetronics, Seeed Studio and much much more.

As always, have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

The post Experimenting with Arduino and IKEA DIODER LED Strips appeared first on tronixstuff.

Display Your City’s Emotional State with Illuminated Snow

[Hunter] wanted to do something a bit more interesting for his holiday lights display last year. Rather than just animated lights, he wanted something that was driven by data. In this case, his display was based on the mood of people in his city. We’ve seen a very similar project in the past, but this one has a few notable differences.

The display runs off of an Arduino. [Hunter] is using an Ethernet shield to connect the Arduino to the Internet. It then monitors all of the latest tweets from users within a 15 mile radius of his area. The tweets are then forwarded to the Alchemy Sentiment API for analysis. The API uses various algorithms and detection methods to identify the overall sentiment within a body of text. [Hunter] is using it to determine the general mood indicated by the text of a given tweet.

Next [Hunter] needed a way to somehow display this information. He opted to use an LED strip. Since the range of sentiments is rather small, [Hunter] didn’t want to display the overall average sentiment. This value doesn’t change much over short periods of time, so it’s not very interesting to see. Instead, he plots the change made since the last sample. This results in a more obvious change to the LED display.

Another interesting thing to note about this project is that [Hunter] is using the snow in his yard to diffuse the light from the LEDs. He’s actually buried the strip under a layer of snow. This has the result of hiding the electronics, but blurring the light enough so you can’t see the individual LEDs. The effect is rather nice, and it’s something different to add to your holiday lights display. Be sure to check out the video below for a demonstration.


Filed under: Arduino Hacks, Holiday Hacks

Sleek Desk Lamp Changes Colors Based on Sun Position

[Connor] was working on a project for his college manufacturing class when he came up with the idea for this sleek desk lamp. As a college student, he’s not fond of having his papers glowing brightly in front of him at night. This lamp takes care of the problem by adjusting the color temperature based on the position of the sun. It also contains a capacities touch sensor to adjust the brightness without the need for buttons with moving parts.

The base is made from two sheets of aluminum and a bar of aluminum. These were cut and milled to the final shape. [Connor] found a nice DC barrel jack from Jameco that fits nicely with this design. The head of the lamp was made from another piece of aluminum bar stock. All of the aluminum pieces are held together with brass screws.

A slot was milled out of the bottom of the head-piece to make room for an LED strip and a piece of 1/8″ acrylic. This piece of acrylic acts as a light diffuser.  Another piece of acrylic was cut and added to the bottom of the base of the lamp. This makes for a nice glowing outline around the bottom that gives it an almost futuristic look.

The capacitive touch sensor is a pretty simple circuit. [Connor] used the Arduino capacitive touch sensor library to make his life a bit easier. The electronic circuit really only requires a single resistor between two Arduino pins. One of the pins is also attached to the aluminum body of the lamp. Now simply touching the lamp body allows [Connor] to adjust the brightness of the lamp.

[Connor] ended up using an Electric Imp to track the sun. The Imp uses the wunderground API to connect to the weather site and track the sun’s location. In the earlier parts of the day, the LED colors are cooler and have more blues. In the evening when the sun is setting or has already set, the lights turn more red and warm. This is easier on the eyes when you are hunched over your desk studying for your next exam. The end result is not only functional, but also looks like something you might find at that fancy gadget store in your local shopping mall.


Filed under: Arduino Hacks

Arduino Powered Digital Kaleidoscope

[Jose's] latest project brings an old visual effect toy up to date with digital electronics. Most of us are familiar with inexpensive kaleidoscope toys. Some of us have even built cheap versions of them with paper tubes, mirrors, and beads. [Jose] wanted to try to recreate the colorful pattern effects created by a kaleidoscope using an Arduino and an addressable LED strip.

The build is actually pretty simple. The base is a disc of PVC cut to just a few inches in diameter. [Jose] started with an addressable LED strip containing 60 LEDs. He then cut it into 12 sections, each containing five LEDs. The smaller strips were then mounted to the disc, similar to spokes on a bicycle wheel. The LED strip already has an adhesive backing, so that part was trivial.

The final step was to add some kind of diffuser screen. The LED strips on their own are not all that interesting. The diffuser allows the light to blend together, forming interesting patterns that are more reminiscent of the patterns you might see in a real kaleidoscope. Without the diffuser you would just see individual points of light, rather than blended color patterns.

The whole thing is controlled by a small Arduino. [Jose] has made the code available at the bottom of his blog post. Be sure to watch the video of the system in action below.


Filed under: Arduino Hacks
Hack a Day 06 Sep 12:00