Introduction: IHarp

Learn how to turn a cheap plastic harp into a fancy iHarp! Simply add a led strip driven by a microcontroller to make the harp an eyecatcher.

Step 1: Parts and Tools

You can use the following parts:

  • A harp (plastic or a real one if you want to go fancy :D)
  • ATTiny 85-20PU microcontroller
  • Resistor 470 Ohms
  • LED strip with WS2812B diodes
  • Breadboard
  • Battery case with on/off switch
  • Cable ties, double sided tape, tape


  • Soldering iron
  • wire stripper (or a knife or scissors)

Step 2: Soldering

Assemble the microcontroller, the led strip and the battery case as shown on the drawing. I used some leftover breadboard. I recommend putting the microcontroller in a socket - this way you can easily reprogram it. Make sure to attach the data line onto the input side of the led strip, it's usually labeled Din or similar.

Step 3: Programming the ATTiny

There are some great instructables out there on how to program the ATTiny. I recommend this one by fellow instructables user danasf: USE A $1 ATTINY TO DRIVE ADDRESSABLE RGB LEDS It also includes a link to Github where you can find a working example. I stripped this example a bit by removing the button support and hardwiring a fix pattern to be shown by the leds.

If you have an Arduino Uno board you can use it as a programmer for programming the ATTiny. Check out these great instructions on details how to set everything up: Programming ATtiny85 with Arduino Uno

Step 4: Put Everything Together

Stick the led strip to the harp. I added some cable ties because I didn't trust the glue. Run the wires to the backside and along the harp to the bottom. I used some brownish tape which matched the harps color quite well. Using some double sided tape stick the battery box to the harp. Again I reinforced with some cable ties.

Step 5: Enjoy the Show!

Flip the switch and enjoy the light show!


  • Add a button and cycle through different patterns - check out the example code referenced in step 3.
  • Add a shake sensor or gyroscope and cycle through different patterns accrodingly
  • ...

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