![](/media/cache/profiles/7c39a5f991bef4a1e34187677a65871d.jpg.50x50_q85.jpg)
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:
Zoom in
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:
Zoom in
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.
Zoom in
Patchage
: Provides a graphical interface to connect jack and midi inputs and outputs.
Zoom in
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 :-)
main.cpp@1:41d2a3984dd7, 2020-04-09 (annotated)
- Committer:
- hudakz
- Date:
- Thu Apr 09 08:23:32 2020 +0000
- Revision:
- 1:41d2a3984dd7
- Parent:
- 0:75d307e38488
Converting Piano Toy to MIDI Keyboard.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
hudakz | 0:75d307e38488 | 1 | #include "stm32f103c8t6.h" |
hudakz | 0:75d307e38488 | 2 | #include "mbed.h" |
hudakz | 0:75d307e38488 | 3 | #include "MidiKey.h" |
hudakz | 0:75d307e38488 | 4 | |
hudakz | 0:75d307e38488 | 5 | DigitalIn a3(PA_3, PullDown); |
hudakz | 0:75d307e38488 | 6 | DigitalIn a4(PA_4, PullDown); |
hudakz | 0:75d307e38488 | 7 | DigitalIn a5(PA_5, PullDown); |
hudakz | 0:75d307e38488 | 8 | DigitalIn a6(PA_6, PullDown); |
hudakz | 0:75d307e38488 | 9 | DigitalIn a7(PA_7, PullDown); |
hudakz | 0:75d307e38488 | 10 | |
hudakz | 0:75d307e38488 | 11 | DigitalInOut a0(PA_0, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 12 | DigitalInOut a1(PA_1, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 13 | DigitalInOut a2(PA_2, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 14 | DigitalInOut b0(PB_0, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 15 | DigitalInOut b1(PB_1, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 16 | DigitalInOut b10(PB_10, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 17 | DigitalInOut b11(PB_11, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 18 | DigitalInOut c15(PC_15, PIN_INPUT, PullDown, 0); |
hudakz | 0:75d307e38488 | 19 | |
hudakz | 0:75d307e38488 | 20 | /** |
hudakz | 0:75d307e38488 | 21 | * @brief |
hudakz | 0:75d307e38488 | 22 | * @note |
hudakz | 0:75d307e38488 | 23 | * @param |
hudakz | 0:75d307e38488 | 24 | * @retval |
hudakz | 0:75d307e38488 | 25 | */ |
hudakz | 0:75d307e38488 | 26 | int main() |
hudakz | 0:75d307e38488 | 27 | { |
hudakz | 0:75d307e38488 | 28 | confSysClock(); //Configure system clock (72MHz HSE clock, 48MHz USB clock) |
hudakz | 0:75d307e38488 | 29 | USBMIDI midi; |
hudakz | 0:75d307e38488 | 30 | MidiKey key[] = |
hudakz | 0:75d307e38488 | 31 | { |
hudakz | 0:75d307e38488 | 32 | MidiKey(midi, 53, a0, a5), // S1 |
hudakz | 0:75d307e38488 | 33 | MidiKey(midi, 54, a1, a5), // S2 |
hudakz | 0:75d307e38488 | 34 | MidiKey(midi, 55, a2, a5), // S3 |
hudakz | 0:75d307e38488 | 35 | MidiKey(midi, 56, b11, a5), // S4 |
hudakz | 0:75d307e38488 | 36 | MidiKey(midi, 57, b10, a5), // S5 |
hudakz | 0:75d307e38488 | 37 | MidiKey(midi, 58, b1, a5), // S6 |
hudakz | 0:75d307e38488 | 38 | MidiKey(midi, 59, b0, a5), // S7 |
hudakz | 0:75d307e38488 | 39 | MidiKey(midi, 60, c15, a6), // S8 |
hudakz | 0:75d307e38488 | 40 | MidiKey(midi, 61, a0, a6), // S9 |
hudakz | 0:75d307e38488 | 41 | MidiKey(midi, 62, a1, a6), // S10 |
hudakz | 0:75d307e38488 | 42 | MidiKey(midi, 63, a2, a6), // S11 |
hudakz | 0:75d307e38488 | 43 | MidiKey(midi, 64, b11, a6), // S12 |
hudakz | 0:75d307e38488 | 44 | MidiKey(midi, 65, b10, a6), // S13 |
hudakz | 0:75d307e38488 | 45 | MidiKey(midi, 66, b1, a6), // S14 |
hudakz | 0:75d307e38488 | 46 | MidiKey(midi, 67, b0, a6), // S15 |
hudakz | 0:75d307e38488 | 47 | MidiKey(midi, 68, c15, a7), // S16 |
hudakz | 0:75d307e38488 | 48 | MidiKey(midi, 69, a0, a7), // S17 |
hudakz | 0:75d307e38488 | 49 | MidiKey(midi, 70, a1, a7), // S18 |
hudakz | 0:75d307e38488 | 50 | MidiKey(midi, 71, a2, a7), // S19 |
hudakz | 0:75d307e38488 | 51 | MidiKey(midi, 72, b11, a7), // S20 |
hudakz | 0:75d307e38488 | 52 | MidiKey(midi, 73, b10, a7), // S21 |
hudakz | 0:75d307e38488 | 53 | MidiKey(midi, 74, b1, a7), // S22 |
hudakz | 0:75d307e38488 | 54 | MidiKey(midi, 75, b0, a7), // S23 |
hudakz | 0:75d307e38488 | 55 | MidiKey(midi, 76, c15, a4), // S24 |
hudakz | 0:75d307e38488 | 56 | MidiKey(midi, 77, a0, a4), // S25 |
hudakz | 0:75d307e38488 | 57 | MidiKey(midi, 78, a1, a4), // S26 |
hudakz | 0:75d307e38488 | 58 | MidiKey(midi, 79, a2, a4), // S27 |
hudakz | 0:75d307e38488 | 59 | MidiKey(midi, 80, b11, a4), // S28 |
hudakz | 0:75d307e38488 | 60 | MidiKey(midi, 81, b10, a4), // S29 |
hudakz | 0:75d307e38488 | 61 | MidiKey(midi, 82, b1, a4), // S30 |
hudakz | 0:75d307e38488 | 62 | MidiKey(midi, 83, b0, a4), // S31 |
hudakz | 0:75d307e38488 | 63 | MidiKey(midi, 84, c15, a3) // S32 |
hudakz | 0:75d307e38488 | 64 | }; |
hudakz | 0:75d307e38488 | 65 | size_t keyLen = sizeof(key) / sizeof(*key); |
hudakz | 0:75d307e38488 | 66 | |
hudakz | 0:75d307e38488 | 67 | while (1) { |
hudakz | 0:75d307e38488 | 68 | for (uint8_t i = 0; i < keyLen; i++) { |
hudakz | 0:75d307e38488 | 69 | key[i].scan(); |
hudakz | 1:41d2a3984dd7 | 70 | wait_ms(2); |
hudakz | 0:75d307e38488 | 71 | } |
hudakz | 0:75d307e38488 | 72 | } |
hudakz | 0:75d307e38488 | 73 | } |