laserHarp

The laserHarp is another Arduino based project. This is also a great excuse to buy a fog machine.

Changing the light level changes the resistance of the photo-resistor.

Essentials:

8 laser pointers aimed at 8 photo-resistors. A laser on the photo-resistor means ‘note off’; while no laser on the photo-resistor means ‘note on’.
A simple voltage divider circuit (x8) is connected to the Arduino digital input pin (x8). Changing the light level changes the resistance of the photo-resistor. When the Arduino detects a ‘high’ signal, the assigned MIDI note is sent out to external equipment, such as a synthesizer, drum machine, computer, etc.

 

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Lights on…
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…Lights off

 

 

The big picture
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Sensors and Arduino
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Freakin’ Lasers

 

 

 

 

 

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Arduino w/sloppy wiring

 

The hardest part is aiming the laser pointers – they each must hit their respective photo-resistor target. The mechanical method which solved this was to put the pointers in tubing (thin electrical conduit), then put this in another piece of tubing (thick electrical conduit), and use set screws to aim the inconsistent lasers. Because of the aiming requirements, this is best mounted to permanent, sturdy structures.

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Another challenge was powering the laser pointers. The existing batteries were replaced with a wallwart, and all the laser pointers were powered together, with the existing push button switches bypassed.

 

VIDEO:

 

 

CODE: