Converting Piano Toy to MIDI Keyboard.
Dependencies: mbed mbed-STM32F103C8T6 USBDevice_STM32F103
How to turn kids' old piano toy to a MIDI keyboard
Inspired by http://www.codetinkerhack.com/2012/11/how-to-turn-piano-toy-into-midi.html I did the same with a Blue Pill module using Mbed.
The old toy was capable to play only one tone at a time:
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A bit of reverse-engineering was needed to re-use the original printed boards. The results are below.
Original PCBs with switches traced to the connector pins:
Schematic:
Wiring:
Then I replaced the original chip with a Blue Pill module and added a USB connector:
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Works great when connected over an USB cable to a Linux Ubuntu 18.04 machine
Installed software:
Yoshimi
: An excellent MIDI software synthesizer for Linux.
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Patchage
: Provides a graphical interface to connect jack and midi inputs and outputs.
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How to use it:
- Connect the Keyboard to the PC over an USB cable.
- Run
Yoshimi
. - Run
Patchage
and connect theMbed USB Audio MIDI 1
output toYoshimi
's input (dragMbed Audio MIDI 1
overyoshimi input
and drop)
- To apply the changes close the
Patchage
! - On
Yoshimi
's toolbar click onInstruments
and selectShow Stored ...
- Select a bank and click on the instrument you'd like to play.
Have fun :-)
Diff: MidiKey.h
- Revision:
- 0:75d307e38488
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MidiKey.h Wed Apr 08 17:47:23 2020 +0000 @@ -0,0 +1,23 @@ +#ifndef MIDIKEY_H +#define MIDIKEY_H + +#include "mbed.h" +#include "USBMIDI.h" + +class MidiKey +{ +public: + MidiKey(USBMIDI& midi, uint8_t note, DigitalInOut& row, DigitalIn& col) : + _midi(midi), _note(note), _row(row), _col(col), _position(0), _lastPos(0) {} + virtual ~MidiKey() {} + void scan(); +private: + USBMIDI& _midi; + uint8_t _note; + DigitalInOut& _row; + DigitalIn& _col; + uint8_t _position; + uint8_t _lastPos; +}; + +#endif // MIDIKEY_H