A laser harp is an electronic instrument that lets you "pluck" laser beams like a harp to play notes. In this guide, you'll learn how to build your own version of a laser harp using a Feather M4 Express or Feather RP2040, a Music Maker FeatherWing and code written in CircuitPython. VL53L4CD time of flight sensors are used to detect when you're playing a note instead of simply detecting the break-beam. This means we can do cool stuff like use the distance data from the time of flight sensors to convert into different MIDI values such as modulation, sustain and velocity.
We use a Music Maker wing which has audio output from MIDI input and a wide variety of musical instruments it can generate sound effects for, see page 32 of the VS1053 datasheet for a full list! Of course you can also generate MIDI-over-USB signals that can be used to control your favorite software synth.
It's hard to mount sensors on the other side of the lasers so we 'cheat' and use high quality ToF distance sensors with precise distance measurements and narrow detection paths. The lasers are only there help you to visualize the detection path of the time of flight sensors so feel free to change the laser colors or positions as you please. The sensors and lasers are mounted so that they are sitting at the same angle.
The Music Maker FeatherWing is used as a MIDI synth. You can change the instrument sound in the CircuitPython code.
The TCA9548A I2C multiplexer allows you to use eight of the VL53L4CD time of flight sensors at the same time even though they all have the same I2C address.
Please look over the following Adafruit Learning System guides for information on the components used.