Laser Harp

[Jared] had a bunch of lasers left over from a previous project that he put to use by producing this laser harp. The look of it reminds us of a very small Koto or perhaps an Autoharp (although the chords can’t be changed on this model).

We’re so glad that [Jared] spent the time to produce such a fine looking body for the instrument. The strings that would traditionally produce the sound on a harp have been replaced with laser diodes shining at Cadmium Sulfide photo resistors. When a beam of light is broken, an Arduino detects the change via the CdS cell and plays a sound through an Altec Lansing speaker inside of the case.

Unfortunately there’s no video available but we’re pretty sure it makes a “pew-pew” sound. There is a link to download the source code but it points to the overview page instead of downloadable code. From the fritzing diagram the CdS cells are part of a voltage divider which provides digital logic to the Arduino. That should be pretty easy to replicate even without seeing [Jared’s] code and we’re sure you can source other Arduino instrument projects for tips on wave shield or midi functionality.

[Thanks The Cheap Vegetable Gardener]

12 thoughts on “Laser Harp

  1. No, there is no video or indication of what the sound from this device is like.

    Since the download link for the source code is broken, this is mainly just showing off the case design at this point. Hopefully they can get the source up for download and we can at least see how he is handling the actual audio.

  2. interesting to note that VCSEL’s can be obtained from defunct laser mice. these are infrared and limited to 0.5mW internally so can be used safely.

    the beam is also single mode so can be used with any old (cheap) IR sensor from another dead optical mouse or even one from a scanner’s home sensor.

    just a thought.

  3. Perhaps it’s just me, but this is a bit bleh without any video. No info on performance or quality of sound from the duino makes Rob a sad panda. That said, a laser koto would make my year, or what’s left of it at least. I’d have to add in tuning changes but that can’t be too hard.

  4. I think the “strings” are placed too close to each other to be really playable without any tactile feedback.

    Also, from what I remember, JMJ harp detects whether the beam in particular position gets reflected off palm, so it’s an open construction shining beams into infinity.

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