Mini invisible MIDI Harp

Picture of Mini invisible MIDI Harp
This is a simple and easy to make MIDI harp, it runs on an Arduino UNO and uses infrared sensors as strings.
It communicates with every recording software that has MIDI.
Its really fun to play with and also very cheap, so enjoy!!

Este es un simple y facil de hacer harpa MIDI, funciona con un Arduino UNO como controlador y tiene sensores infrarojos como cuerdas.
Puede comunicarse con cualquier software de grabacion que tenga la opcion de usar instrumentos MIDI.

Es muy divertida y bastante barato, disfruten! 

Made on August 17th 2013 for the August Build night with Jameco

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Step 1: Materials

List of materials:

- 2N2222 Transistor (x14) 
- Infrared LED's (x7)
-Infrared reciever (x7)
-100 ohm resistors (x7)
-1K ohm resistors (x7)
-10K ohm resistors (x7)
-400 ohm resistors (x7)
-One sided PCB
-Arduino UNO
-Stranded cable, plenty.
-Breadboard pins 
-Glue for wood
- PCB etching solution (Ferric chloride) 

- Dremmel
-Solder iron
-Insulating tape
Permanent marker
-Nail polish remover
-And everything you find helpful

- Transistor 2N2222  (x14)
- LEDs infrarojos (x7)
-Receptores infrarojos (x7)
-100 ohm resistores (x7)
-1K ohm resistores (x7)
-10K ohm resistores (x7)
-400 ohm resistores (x7)
-PCB con cobre de un solo lado
-Arduino UNO
-Cable multifilar en cantidades necesarias.
-Pines de protoboard
-Pegamento de madera
-Liquido para PCB (Clorato de ferro)

- Dremmel
- Alicates
-Soldadora o cautin.
-Cinta aislante
-Marcador permanente
-Quita esmalte de uñas.
-Todo lo que encuentres necesario.

codewizard584 months ago

Nice project, I used 6 IR beams in my Broomstick guitar you can find on youtube or I wired the IR dectors directly to the analog inputs. I multiplex 6 IR Leds and 6 optical Leds and use a PS/2 mouse for the finger board control.

abrown1257 months ago
Great little thing this but I have a problem with step 3, you say solder the components as shown on the circuit, you don't mention what value resistor goes where and the colour bands on your resistors (in the pictures) don't seem to match the resistor values in the components list. Can anyone please give me a hand with this, I am still a bit of an electronics noob.
retnaa10 months ago
hola que tal oye me podrias agregar en dropbox o pasarme el diseño del circuito
mi correo es
ep049010 months ago
Could you please email me the arduino code. Under step 5 i see arduino code dropbox link but the file is a .pd just like the other link which is a .pd file.

Wyle_E11 months ago
Ferric chloride is nasty stuff, and needs hazmat disposal. There are better etchants. I just realized that Instructables doesn't have a search function, but a Google search on "cupric chloride etchant" will find some articles. CuCl2 is just as nasty, but you don't have to dispose of it after an etch. Bubbling air through the bath regenerates the etchant.
musictechbolivia (author)  Wyle_E11 months ago
Thanks for the tip! there has to be better ways to make a good PCB, ill do more research on it, thanks!
Jgniklu11 months ago
Where can I get the arduino code and pd file?
musictechbolivia (author)  Jgniklu11 months ago
I just uploaded the dropbox link to download the files, sorry about that. there must have been a mistake on my end.