MIDI Breadboard Instrument — Desk Rave & 16-Track Symphony

# 1. Clone the repository
git clone https://github.com/ertunc-ozbay/midi-breadboard-instrument.git
cd midi-breadboard-instrument

# 2. (Optional) Convert a custom .mid file into an RLE-compressed C struct array
pip install mido
python3 scripts/midi_to_c.py scripts/midillis/Alla_Turca/Alla_Turca.mid > my_track.h

# 3. Build and flash the 16-track firmware to ESP32
source ~/esp/esp-idf/export.sh
idf.py build
idf.py -p /dev/ttyUSB0 flash monitor

#!/usr/bin/env python3
import sys, mido

def convert_midi_to_c(midi_filename):
    mid = mido.MidiFile(midi_filename)
    safe_name = midi_filename.split('/')[-1].replace('.mid', '').replace('-', '_')
    print(f"const SequenceStep midi_{safe_name}[] = {{")

    active_melody_notes = set()
    time_accum = 0.0
    trigger_kick = trigger_hat = False
    rle_freq, rle_dur, rle_kick, rle_hat = -1, 0, False, False

    for msg in mid:
        time_accum += msg.time
        if msg.type in ['note_on', 'note_off'] and time_accum > 0.01:
            duration_ms = int(time_accum * 1000)
            freq = int(440.0 * (2.0 ** ((max(active_melody_notes) - 69) / 12.0))) if active_melody_notes else 0

            # RLE Engine: coalesce contiguous identical frequency & drum states
            if freq == rle_freq and trigger_kick == rle_kick and trigger_hat == rle_hat:
                rle_dur += duration_ms
            else:
                if rle_dur > 0:
                    print(f"    {{{rle_freq}, {rle_dur}, {str(rle_kick).lower()}, {str(rle_hat).lower()}}},")
                rle_freq, rle_dur, rle_kick, rle_hat = freq, duration_ms, trigger_kick, trigger_hat

            time_accum, trigger_kick, trigger_hat = 0.0, False, False

typedef struct {
    uint16_t frequency; // Melody pitch in Hz (driven by 13-bit LEDC PWM on GPIO 25)
    uint16_t duration;  // Step duration in ms (scaled live by PCNT rotary speed)
    bool kick_drum;     // Triggers Active Buzzer 1 (GPIO 26) + Kick LED (GPIO 21)
    bool hi_hat;        // Triggers Active Buzzer 2 (GPIO 27) + Hat LED (GPIO 22)
} SequenceStep;

void app_main(void) {
    printf("Desk Rave: 16-Track Symphony Edition Initializing...\n");
    init_hardware();

    // Core 0: 30 FPS SPI OLED Framebuffer Visualizer & 50ms Button Polling
    xTaskCreatePinnedToCore(oled_visualizer_task, "oled_task",  4096, NULL, 4, NULL, 0);
    xTaskCreatePinnedToCore(button_task,          "btn_task",   4096, NULL, 5, NULL, 0);

    // Core 1: Dedicated Real-Time Audio Synthesizer & PCNT Rotary Scaling
    xTaskCreatePinnedToCore(buzzer_sequence_task, "music_task", 4096, NULL, 5, NULL, 1);
}