Laserharp

Latest revision as of 20:52, 8 August 2023

For science fesrival we created a laser harp

Here is how to get the software part to run

MIDI libraries for the arduino, used to format midi messages sent to the usb port : https://github.com/FortySevenEffects/arduino_midi_library

On a raspberry, or linux PC, to allow the midi messages to be managed by the system, by creating an ALSA midi port on the raspberry : https://github.com/cjbarnes18/ttymidi/

And then install fluidsynth, a very nice synthesizer capable of playing hundreds of different instruments based upon freely available sound files : http://www.fluidsynth.org/

Here is a typescript:

• sudo apt-get install libasound2-dev
• git clone https://github.com/cjbarnes18/ttymidi.git
• cd ttymidi/
• make
• sudo make install

connect the harp

find the device name

• sudo dmesg

do a test run. Play some notes, the values should be displayed

• ttymidi -s /dev/ttyACM0 -v

Connect the midi device to the synth

• ttymidi -s /dev/ttyACM0 &
• fluidsynth --server --no-shell --audio-driver=pulseaudio --gain=1.0 --reverb=0.42 --chorus=0.42 /usr/share/sounds/sf2/FluidR3_GM.sf2 &
• aconnect -i
• aconnect -o

In the above outputs search for the ttymidi (usually 128) and fluidsynth (usually 129) and connect them together

• aconnect 128 129

Now you can play the harp.

Unsolved issues:

The right 2 lasers are for instrument+ and instrument-, but you can only switch between several times the same instrument and the drumkit.