Convert an outdated phone right into a MIDI instrument

MIDI (Musical Instrument Digital Interface) is a unbelievable commonplace as a result of it’s versatile sufficient to embody nearly all devices, however easy sufficient to work with utilizing low-power digital {hardware}. A typical MIDI message accommodates three bytes. The primary is a standing byte that describes the motion (like “word on”) and the channel to make use of, the second byte accommodates the word to play, and the third byte defines the rate. As a result of a single change can act as a set off to ship a MIDI message, one can flip an outdated contact tone phone right into a MIDI instrument.

The telephone used on this challenge and most others prefer it have numeric keypads arrange in the identical manner as keyboards, with a matrix decreasing the variety of I/O pins wanted on a related microcontroller. Multiply the quantity or rows within the matrix by the variety of columns to get the utmost variety of keys. This specific keypad had a mixed row/column whole of 11, which suggests it might help as much as 30 distinctive keys. However solely 12 of these are related, so the tutorial consists of directions on how you can determine the important thing that every row/column combo triggers. As soon as you already know that data, you’ll be able to join the row and column wires to the I/O pins of an Arduino.

The supplied Arduino sketch will deal with just about every little thing else after you assign the pin numbers, however it’s nonetheless price understanding the way it works. First, it loops by way of the entire crucial rows and columns to find out the states of each button. From there, it sends the assigned MIDI message by way of a MIDI jack related to the Arduino by way of three wires. You may assign pre-made messages to particular keys, or you will get artistic and create particular algorithms that alter the messages based mostly on key combos or sequences. Join any MIDI output gadget to the MIDI jack to synthesize or pattern the notes, or join it to a pc to document MIDI sequences.

As a bonus, this tutorial even explains how you can convert the handset right into a useful microphone you can amplify, so you’ll be able to have vocals to accompany your MIDI music.