This weekend project consists in turning your MIDI-capable keyboard or digital piano into a full piano learning & tutoring system, i.e., an interactive lighted keyboard/piano based on the opensource MuseScore sheet music editor & player, a common Arduino board and an LED stripe. The system will let you practice a piano piece on the keyboard without any need for reading sheet music: just load any MIDI file on MuseScore, play it activating the Piano Tutor function, and then follow the LEDs lighting up on the stripe deployed along your keyboard, repeating as many times as needed.

Project Concept and System Operation

The core of this project is to build a "bridge" between digital data (MIDI) and physical display (LED). The system operates collaboratively as follows:

1. MuseScore (The Conductor): Acts as the data source. When we open a MIDI file or sheet music and start playing a song, MuseScore sends MIDI Out signals via the USB port.
2. Arduino (The Translator): The Arduino board receives MIDI data via Serial Communication, then "decodes" (parses) which notes are pressed (Note On) or released (Note Off), and converts that MIDI Note Number value into a pixel position on the LED strip.
3. LED Strip (The Visualizer): The LED strip (often an Addressable type like WS2812B) is installed above the piano keys. Upon receiving commands from the Arduino, the lights illuminate immediately at the position of the key that needs to be pressed.

In-depth Look at Equipment and Engineering Principles

For the project to work precisely and without latency, we need to understand the main components as follows:

1. Arduino Board (Microcontroller)

Arduino boards (such as Uno, Nano, or Leonardo) perform logic processing. Especially boards with a USB-to-Serial chip that supports high-speed data transmission, or if using a Leonardo/Micro, we can implement Native MIDI-over-USB directly, which allows the computer to recognize the Arduino as a musical instrument.

2. Addressable LED Strip (WS2812B)

Why this model? Because the WS2812B uses a single signal wire (One-wire protocol) to control each LED independently. Engineers will map the MIDI Note Number (which for an 88-key piano typically starts from note number 21 to 108) to the LED Index (0, 1, 2, ...) according to the actual installation position.

3. Power Management

An 88-LED strip can draw a relatively high current (approximately 3-4 Amps if illuminated at full white brightness). Therefore, connecting an external 5V power supply directly to the LED strip (not through the Arduino board) is crucial to prevent damage to the board from overcurrent.

Code Logic Analysis

The internal operation process of the Arduino Code will have the following key structure:

• MIDI Message Parsing: The program will constantly listen for data bytes sent from MuseScore, focusing on the Status Byte that indicates whether it's a Note On (start playing note) or Note Off (stop playing note) event.
• Data Byte Mapping: When a Note On event is detected, the program will read Data Byte 1 (Note Number) to identify the key position and Data Byte 2 (Velocity) to determine the light's brightness.
• FastLED Library: Using a library like FastLED allows for smooth control of RGB pixels. In the code, commands such as leds[mapped_index] = CRGB::Blue; will be used when a note is pressed, and leds[mapped_index] = CRGB::Black; when a note is released.

Conclusion and Project Highlights

This project is not only an excellent music practice tool but also a great exercise for Embedded Developers to learn about:

• Serial Communication Protocol between computer software and hardware.
• Real-time Data management to ensure the lights display in sync with the audible music.
• Mathematical Data Mapping for matching data sets (Note Number) to display pixels.

If you have an electric piano at home and an unused Arduino board, try dedicating a weekend to building this tool. You'll find that practicing your favorite piano pieces becomes much easier and more enjoyable!

Please check out instructions in this tutorial.