PianoTutor+

This project has been developed for the course of Component Based Software Design, Master of Engineering in Embedded Computing Systems (University of Pisa and Sant'Anna School of Advanced Studies).

Assignment

The aim of this project was to port the PianoTutor already developed by prof. Tommaso Cucinotta to a Raspberry Pi.

For this ported version, it has been decided to substitute the Arduino Uno with a Raspberry Pi, developing an ALSA component and driving the LEDs strip using the available GPIO pins. A component like that allows you to run it independently from the host running MuseScore, either on the same host or on a different one (using aseqnet to connect ALSA ports on different nodes).

Dependencies

The component, to control the LED strip, depends on the rpi_ws281x, a simple and powerful library developed by Jeremy Garff. Refer to that repository for building instructions.

Also, you have to use the MuseScore version patched by prof. Cucinotta so to work with PianoTutor. Also in this case, refer to that repository for building it from source.

Then, you can install the other building dependencies with

$ sudo apt-get install git make g++ libasound2-dev

Build

First, move into the cloned repository. The component is shipped with a Makefile so to ease the building process. Make sure to change the LED_STRIP_LIB_FOLDER variable inside the Makefile to point to the correct install location for the rpi_ws281x library.

Then, either run

$ make debug

or

$ make

depending on if you are interested into printing debug messages or not while running the program.

Configure

The program relies on a configuration file for simply configuring its behaviour. It can be named whatever you want, as long as the content follows the right syntax. This gives you a lot of flexibility for the various parameters, without the need to recompile each time the whole program (refer to rpi_ws281x for a list of the available GPIO pins and DMA channels).

Run

You can easily run the program as

$ ./bin/pianotutor+ -f deploy.conf

Notice that the program must be up and running to connect to the MIDI port: once terminated, the port is automatically destroyed, along with all the previous made connections.

Headless Raspberry Pi

In case you are using a headless Raspberry Pi, you need to use aseqnet to allow your PC/laptop running MuseScore to correctly communicate with PianoTutor+. This configuration is depicted in the picture below

With this approach, we will call the Raspberry Pi a headless device since it would run without a monitor or peripherals such as mouse or keyboard, so you would require an SSH connection.

On the Raspberry Pi, type

$ aseqnet

to open a ALSA sequencer server. Then, type

$ aplaymidi -l

and take note of the PianoTutor+ and network sequencer ALSA ports (something like 128:0). Finally, connect them using

$ aconnect <Network port> <PianoTutor+ port>

On the host running MuseScore, type

$ aseqnet <raspberry ip address> <Network port>

to connect to the ALSA sequencer server. Then, from inside MuseScore settings, set the keyboard as MIDI input and the network sequencer as MIDI output.

Raspberry Pi with display

Having a display connected to the Raspberry Pi, you could run MuseScore directly on it (however, I had some troubles either in compiling/running MuseScore on a Raspberry Pi 2). This configuration is depicted in the functional diagram below

Anyway, with this configuration, you simply have to run MuseScore and, from its settings, set the keyboard as MIDI input and PianoTutor+ as MIDI output.