.gitignore

@@ -1,2 +0,0 @@
-noicesynth_linux
-miniaudio.h

AudioThread.cpp

@@ -17,6 +17,12 @@ const int16_t AMPLITUDE = 16383; // Use a lower amplitude to avoid clipping (max
 I2S i2s(OUTPUT);
 
 // --- Synthesizer State ---
+// Frequencies for a C-Major scale to pick from
+const float NOTE_FREQUENCIES[] = {
+  261.63, 293.66, 329.63, 349.23, 392.00, 440.00, 493.88, 523.25
+};
+const int NUM_NOTES = sizeof(NOTE_FREQUENCIES) / sizeof(NOTE_FREQUENCIES[0]);
+
 float currentFrequency = 440.0f;
 double phase = 0.0;
 unsigned long lastNoteChangeTime = 0;
@@ -44,39 +50,15 @@ void loopAudio() {
   // Every 500ms, pick a new random note to play
   if (now - lastNoteChangeTime > 500) {
     lastNoteChangeTime = now;
-    int noteIndex = random(0, SCALES[currentScaleIndex].numNotes);
+    int noteIndex = random(0, NUM_NOTES);
-    
+    currentFrequency = NOTE_FREQUENCIES[noteIndex];
-    // Calculate frequency based on key, scale, and octave
-    const float baseFrequency = 261.63f; // C4
-    float keyFrequency = baseFrequency * pow(2.0f, currentKeyIndex / 12.0f);
-    int semitoneOffset = SCALES[currentScaleIndex].semitones[noteIndex];
-    currentFrequency = keyFrequency * pow(2.0f, semitoneOffset / 12.0f);
-
     Serial.println("Playing note: " + String(currentFrequency) + " Hz");
   }
 
   // Generate the sine wave sample
-  int16_t sample;
   double phaseIncrement = 2.0 * M_PI * currentFrequency / SAMPLE_RATE;
   phase = fmod(phase + phaseIncrement, 2.0 * M_PI);
-
+  int16_t sample = static_cast<int16_t>(AMPLITUDE * sin(phase));
-  switch (currentWavetableIndex) {
-    case 0: // Sine
-        sample = static_cast<int16_t>(AMPLITUDE * sin(phase));
-        break;
-    case 1: // Square
-        sample = (phase < M_PI) ? AMPLITUDE : -AMPLITUDE;
-        break;
-    case 2: // Saw
-        sample = static_cast<int16_t>(AMPLITUDE * (1.0 - (phase / M_PI)));
-        break;
-    case 3: // Triangle
-        sample = static_cast<int16_t>(AMPLITUDE * (2.0 * fabs(phase / M_PI - 1.0) - 1.0));
-        break;
-    default:
-        sample = 0;
-        break;
-  }
 
   // Write the same sample to both left and right channels (mono audio).
   // This call is blocking and will wait until there is space in the DMA buffer.

EMULATOR.md

@@ -1,43 +0,0 @@
-# NoiceSynth Linux Emulator
-
-This folder contains a Linux-based prototype for the NoiceSynth engine. It allows you to develop and visualize the DSP code on a desktop computer before deploying it to the RP2040 hardware.
-
-## Architecture
-
-*   **Engine (`synth_engine.cpp`):** The exact same C++ code used on the microcontroller. It uses fixed-point math (or integer-based phase accumulation) to generate audio.
-*   **Host (`main.cpp`):** A Linux wrapper that uses:
-    *   **Miniaudio:** For cross-platform audio output.
-    *   **SDL2:** For real-time oscilloscope visualization.
-
-## Quick Start (Distrobox)
-
-If you don't want to install dependencies manually, use the included script. It creates a lightweight container, installs the tools, and compiles the project.
-
-1.  Ensure you have `distrobox` and a container engine (Docker or Podman) installed.
-2.  Run the build script:
-    ```bash
-    ./compile_with_distrobox.sh
-    ```
-3.  Run the synthesizer:
-    ```bash
-    ./noicesynth_linux
-    ```
-
-## Manual Build
-
-If you prefer to build directly on your host machine:
-
-1.  **Install Dependencies:**
-    *   **Debian/Ubuntu:** `sudo apt install build-essential libsdl2-dev wget`
-    *   **Fedora:** `sudo dnf install gcc-c++ SDL2-devel wget`
-    *   **Arch:** `sudo pacman -S base-devel sdl2 wget`
-
-2.  **Download Miniaudio:**
-    ```bash
-    wget https://raw.githubusercontent.com/mackron/miniaudio/master/miniaudio.h
-    ```
-
-3.  **Compile:**
-    ```bash
-    make
-    ```

Makefile

@@ -1,18 +0,0 @@
-# Compiler and flags
-CXX = g++
-CXXFLAGS = -std=c++17 -Wall -Wextra -I. $(shell sdl2-config --cflags)
-LDFLAGS = -ldl -lm -lpthread $(shell sdl2-config --libs)
-
-# Source files
-SRCS = main.cpp synth_engine.cpp
-
-# Output binary
-TARGET = noicesynth_linux
-
-all: $(TARGET)
-
-$(TARGET): $(SRCS)
-	$(CXX) $(CXXFLAGS) -o $(TARGET) $(SRCS) $(LDFLAGS)
-
-clean:
-	rm -f $(TARGET)

SharedState.cpp

@@ -2,31 +2,4 @@
 
 volatile unsigned long lastLoop0Time = 0;
 volatile unsigned long lastLoop1Time = 0;
-volatile bool watchdogActive = false;
+volatile bool watchdogActive = false;
-
-UIState currentState = UI_MENU;
-volatile int menuSelection = 0;
-
-const MenuItem MENU_ITEMS[] = {
-  { "Scale Type", UI_EDIT_SCALE_TYPE },
-  { "Scale Key", UI_EDIT_SCALE_KEY },
-  { "Wavetable", UI_EDIT_WAVETABLE }
-};
-const int NUM_MENU_ITEMS = sizeof(MENU_ITEMS) / sizeof(MENU_ITEMS[0]);
-
-const Scale SCALES[] = {
-  { "Major",      { 0, 2, 4, 5, 7, 9, 11, 12 }, 8 },
-  { "Minor",      { 0, 2, 3, 5, 7, 8, 10, 12 }, 8 },
-  { "Pentatonic", { 0, 2, 4, 7, 9, 12, 14, 16 }, 8 },
-  { "Blues",      { 0, 3, 5, 6, 7, 10, 12, 14 }, 8 }
-};
-const int NUM_SCALES = sizeof(SCALES) / sizeof(SCALES[0]);
-volatile int currentScaleIndex = 0;
-
-const char* KEY_NAMES[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
-const int NUM_KEYS = sizeof(KEY_NAMES) / sizeof(KEY_NAMES[0]);
-volatile int currentKeyIndex = 0; // C
-
-const char* WAVETABLE_NAMES[] = {"Sine", "Square", "Saw", "Triangle"};
-const int NUM_WAVETABLES = sizeof(WAVETABLE_NAMES) / sizeof(WAVETABLE_NAMES[0]);
-volatile int currentWavetableIndex = 0; // Sine

SharedState.h

@@ -7,39 +7,4 @@ extern volatile unsigned long lastLoop0Time;
 extern volatile unsigned long lastLoop1Time;
 extern volatile bool watchdogActive;
 
-enum UIState {
-  UI_MENU,
-  UI_EDIT_SCALE_TYPE,
-  UI_EDIT_SCALE_KEY,
-  UI_EDIT_WAVETABLE
-};
-
-struct Scale {
-  const char* name;
-  const int semitones[8];
-  int numNotes;
-};
-
-struct MenuItem {
-  const char* label;
-  UIState editState;
-};
-
-extern UIState currentState;
-extern const MenuItem MENU_ITEMS[];
-extern const int NUM_MENU_ITEMS;
-extern volatile int menuSelection;
-
-extern const Scale SCALES[];
-extern const int NUM_SCALES;
-extern volatile int currentScaleIndex;
-
-extern const char* KEY_NAMES[];
-extern const int NUM_KEYS;
-extern volatile int currentKeyIndex;
-
-extern const char* WAVETABLE_NAMES[];
-extern const int NUM_WAVETABLES;
-extern volatile int currentWavetableIndex;
-
 #endif // SHAREDSTATE_H

UIThread.cpp

@@ -1,188 +1,12 @@
 #include "UIThread.h"
 #include "SharedState.h"
 #include <Arduino.h>
-#include <Wire.h>
-#include <Adafruit_GFX.h>
-#include <Adafruit_SSD1306.h>
-
-#define SCREEN_WIDTH 128
-#define SCREEN_HEIGHT 64
-#define OLED_RESET    -1
-#define SCREEN_ADDRESS 0x3C
-
-// I2C Pins (GP4/GP5)
-#define PIN_SDA 4
-#define PIN_SCL 5
-
-// Encoder Pins
-#define PIN_ENC_CLK 12
-#define PIN_ENC_DT  13
-#define PIN_ENC_SW 14
-
-Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
-
-volatile int8_t encoderDelta = 0;
-static uint8_t prevNextCode = 0;
-static uint16_t store = 0;
-
-// Button state
-static int lastButtonReading = HIGH;
-static int currentButtonState = HIGH;
-static unsigned long lastDebounceTime = 0;
-static bool buttonClick = false;
-
-void handleInput();
-void drawUI();
-
-// --- ENCODER INTERRUPT ---
-// Robust Rotary Encoder reading
-void readEncoder() {
-  static int8_t rot_enc_table[] = {0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0};
-
-  prevNextCode <<= 2;
-  if (digitalRead(PIN_ENC_DT)) prevNextCode |= 0x02;
-  if (digitalRead(PIN_ENC_CLK)) prevNextCode |= 0x01;
-  prevNextCode &= 0x0f;
-
-  // If valid state
-  if (rot_enc_table[prevNextCode]) {
-    store <<= 4;
-    store |= prevNextCode;
-    if ((store & 0xff) == 0x2b) encoderDelta--;
-    if ((store & 0xff) == 0x17) encoderDelta++;
-  }
-}
 
 void setupUI() {
-  Wire.setSDA(PIN_SDA);
+  // This is the UI thread, running on core 0. For this example, we do nothing here.
-  Wire.setSCL(PIN_SCL);
-  Wire.begin();
-
-    pinMode(PIN_ENC_CLK, INPUT_PULLUP);
-    pinMode(PIN_ENC_DT, INPUT_PULLUP);
-    pinMode(PIN_ENC_SW, INPUT_PULLUP);
-    attachInterrupt(digitalPinToInterrupt(PIN_ENC_CLK), readEncoder, CHANGE);
-    attachInterrupt(digitalPinToInterrupt(PIN_ENC_DT), readEncoder, CHANGE);
-
-  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
-    Serial.println(F("SSD1306 allocation failed"));
-    for(;;);
-  }
-
-  display.clearDisplay();
-  display.display();
-}
-
-void handleInput() {
-    // Handle Encoder Rotation
-    int rotation = 0;
-    noInterrupts();
-    rotation = encoderDelta;
-    encoderDelta = 0;
-    interrupts();
-
-    if (rotation != 0) {
-        switch (currentState) {
-            case UI_MENU:
-                menuSelection += rotation;
-                while (menuSelection < 0) menuSelection += NUM_MENU_ITEMS;
-                menuSelection %= NUM_MENU_ITEMS;
-                break;
-            case UI_EDIT_SCALE_TYPE:
-                currentScaleIndex += rotation;
-                while (currentScaleIndex < 0) currentScaleIndex += NUM_SCALES;
-                currentScaleIndex %= NUM_SCALES;
-                break;
-            case UI_EDIT_SCALE_KEY:
-                currentKeyIndex += rotation;
-                while (currentKeyIndex < 0) currentKeyIndex += NUM_KEYS;
-                currentKeyIndex %= NUM_KEYS;
-                break;
-            case UI_EDIT_WAVETABLE:
-                currentWavetableIndex += rotation;
-                while (currentWavetableIndex < 0) currentWavetableIndex += NUM_WAVETABLES;
-                currentWavetableIndex %= NUM_WAVETABLES;
-                break;
-        }
-    }
-
-    // Handle Button Click
-    int reading = digitalRead(PIN_ENC_SW);
-    if (reading != lastButtonReading) {
-        lastDebounceTime = millis();
-    }
-
-    if ((millis() - lastDebounceTime) > 50) {
-        if (reading != currentButtonState) {
-            currentButtonState = reading;
-            if (currentButtonState == LOW) {
-                buttonClick = true;
-            }
-        }
-    }
-    lastButtonReading = reading;
-
-    if (buttonClick) {
-        buttonClick = false;
-        if (currentState == UI_MENU) {
-            currentState = MENU_ITEMS[menuSelection].editState;
-        } else {
-            currentState = UI_MENU;
-        }
-    }
-}
-
-void drawUI() {
-    display.clearDisplay();
-    display.setTextSize(1);
-    display.setTextColor(SSD1306_WHITE);
-    display.setCursor(0, 0);
-
-    if (currentState == UI_MENU) {
-        for (int i = 0; i < NUM_MENU_ITEMS; i++) {
-            if (i == menuSelection) {
-                display.fillRect(0, i * 10, SCREEN_WIDTH, 10, SSD1306_WHITE);
-                display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
-            } else {
-                display.setTextColor(SSD1306_WHITE);
-            }
-            display.setCursor(2, i * 10 + 1);
-            display.print(MENU_ITEMS[i].label);
-            display.print(": ");
-
-            // Display current value
-            switch (MENU_ITEMS[i].editState) {
-                case UI_EDIT_SCALE_TYPE: display.print(SCALES[currentScaleIndex].name); break;
-                case UI_EDIT_SCALE_KEY: display.print(KEY_NAMES[currentKeyIndex]); break;
-                case UI_EDIT_WAVETABLE: display.print(WAVETABLE_NAMES[currentWavetableIndex]); break;
-                default: break;
-            }
-        }
-    } else {
-        // In an edit screen
-        const char* title = MENU_ITEMS[menuSelection].label;
-        const char* value = "";
-        switch (currentState) {
-            case UI_EDIT_SCALE_TYPE: value = SCALES[currentScaleIndex].name; break;
-            case UI_EDIT_SCALE_KEY: value = KEY_NAMES[currentKeyIndex]; break;
-            case UI_EDIT_WAVETABLE: value = WAVETABLE_NAMES[currentWavetableIndex]; break;
-            default: break;
-        }
-        display.println(title);
-        display.drawLine(0, 10, SCREEN_WIDTH, 10, SSD1306_WHITE);
-        display.setCursor(10, 25);
-        display.setTextSize(2);
-        display.print(value);
-        display.setTextSize(1);
-        display.setCursor(0, 50);
-        display.println(F("(Press to confirm)"));
-    }
-
-    display.display();
 }
 
 void loopUI() {
-  handleInput();
+  // The loop on core 0 is responsible for updating the UI. In this simple example, it does nothing.
-  drawUI();
+  delay(100);
-  delay(20); // Prevent excessive screen refresh
 }

compile_with_distrobox.sh

@@ -1,44 +0,0 @@
-#!/bin/bash
-set -e
-
-# Configuration
-CONTAINER_NAME="noicesynth-builder"
-IMAGE="archlinux:latest"
-
-# 1. Check for Distrobox
-if ! command -v distrobox &> /dev/null; then
-    echo "Error: distrobox is not installed on your system."
-    exit 1
-fi
-
-# 2. Create Container (if it doesn't exist)
-# We use Arch Linux for easy access to latest toolchains and SDL2
-if ! distrobox list | grep -q "$CONTAINER_NAME"; then
-    echo "Creating container '$CONTAINER_NAME'..."
-    distrobox create --image "$IMAGE" --name "$CONTAINER_NAME" --yes
-fi
-
-# 3. Execute Build Inside Container
-PROJECT_DIR=$(pwd)
-echo "Entering container to build..."
-distrobox enter "$CONTAINER_NAME" --additional-flags "--workdir $PROJECT_DIR" -- sh -c '
-    set -e # Ensure script exits on error inside the container too
-    # A. Install Dependencies (only if missing)
-    # We check for sdl2-config and wget to see if dev tools are present
-    if ! command -v sdl2-config &> /dev/null || ! command -v wget &> /dev/null; then
-        echo "Installing compiler and libraries..."
-        sudo pacman -Syu --noconfirm base-devel sdl2 wget
-    fi
-
-    # B. Download miniaudio.h (if missing)
-    if [ ! -f miniaudio.h ]; then
-        echo "Downloading miniaudio.h..."
-        wget https://raw.githubusercontent.com/mackron/miniaudio/master/miniaudio.h
-    fi
-
-    # C. Compile
-    echo "Compiling Project..."
-    make
-'
-
-echo "Build Success! Run ./noicesynth_linux to start the synth."

main.cpp

@@ -1,150 +0,0 @@
-#define MINIAUDIO_IMPLEMENTATION
-#include "miniaudio.h"
-#include <SDL2/SDL.h>
-#include <vector>
-#include <atomic>
-#include "synth_engine.h" // Include our portable engine
-
-#include <stdio.h>
-
-// --- Configuration ---
-const uint32_t SAMPLE_RATE = 44100;
-const uint32_t CHANNELS = 1; // Mono
-const int WINDOW_WIDTH = 800;
-const int WINDOW_HEIGHT = 600;
-
-// --- Visualization Buffer ---
-const size_t VIS_BUFFER_SIZE = 8192;
-std::vector<int16_t> vis_buffer(VIS_BUFFER_SIZE, 0);
-std::atomic<size_t> vis_write_index{0};
-
-// --- Global Synth Engine Instance ---
-// The audio callback needs access to our synth, so we make it global.
-SynthEngine engine(SAMPLE_RATE);
-
-/**
- * @brief The audio callback function that miniaudio will call.
- *
- * This function acts as the bridge between the audio driver and our synth engine.
- * It asks the engine to fill the audio buffer provided by the driver.
- */
-void data_callback(ma_device* pDevice, void* pOutput, const void* pInput, ma_uint32 frameCount) {
-    (void)pDevice; // Unused
-    (void)pInput;  // Unused
-
-    // Cast the output buffer to the format our engine expects (int16_t).
-    int16_t* pOutputS16 = (int16_t*)pOutput;
-
-    // Tell our engine to process `frameCount` samples and fill the buffer.
-    engine.process(pOutputS16, frameCount);
-
-    // Copy to visualization buffer
-    size_t idx = vis_write_index.load(std::memory_order_relaxed);
-    for (ma_uint32 i = 0; i < frameCount; ++i) {
-        vis_buffer[idx] = pOutputS16[i];
-        idx = (idx + 1) % VIS_BUFFER_SIZE;
-    }
-    vis_write_index.store(idx, std::memory_order_relaxed);
-}
-
-int main(int argc, char* argv[]) {
-    (void)argc; (void)argv;
-
-    // --- Init SDL ---
-    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
-        printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
-        return -1;
-    }
-
-    SDL_Window* window = SDL_CreateWindow("NoiceSynth Scope", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_SHOWN);
-    if (!window) return -1;
-
-    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
-    if (!renderer) return -1;
-
-    ma_device_config config = ma_device_config_init(ma_device_type_playback);
-    config.playback.format   = ma_format_s16; // Must match our engine's output format
-    config.playback.channels = CHANNELS;
-    config.sampleRate        = SAMPLE_RATE;
-    config.dataCallback      = data_callback;
-
-    ma_device device;
-    if (ma_device_init(NULL, &config, &device) != MA_SUCCESS) {
-        printf("Failed to initialize playback device.\n");
-        SDL_DestroyRenderer(renderer);
-        SDL_DestroyWindow(window);
-        SDL_Quit();
-        return -1;
-    }
-
-    printf("Device Name: %s\n", device.playback.name);
-
-    ma_device_start(&device);
-
-    // --- Main Loop ---
-    bool quit = false;
-    SDL_Event e;
-
-    while (!quit) {
-        while (SDL_PollEvent(&e) != 0) {
-            if (e.type == SDL_QUIT) {
-                quit = true;
-            }
-        }
-
-        // Clear screen
-        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
-        SDL_RenderClear(renderer);
-
-        // Draw Waveform
-        SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255); // Green
-
-        // Determine read position (snapshot atomic write index)
-        size_t write_idx = vis_write_index.load(std::memory_order_relaxed);
-        
-        // Find trigger (zero crossing) to stabilize the display
-        // Look back from write_idx to find a stable point
-        size_t search_start_offset = 2000; 
-        size_t read_idx = (write_idx + VIS_BUFFER_SIZE - search_start_offset) % VIS_BUFFER_SIZE;
-        
-        // Simple trigger search: find crossing from negative to positive
-        for (size_t i = 0; i < 1000; ++i) {
-            int16_t s1 = vis_buffer[read_idx];
-            size_t next_idx = (read_idx + 1) % VIS_BUFFER_SIZE;
-            int16_t s2 = vis_buffer[next_idx];
-            
-            if (s1 <= 0 && s2 > 0) {
-                read_idx = next_idx; // Found trigger
-                break;
-            }
-            read_idx = next_idx;
-        }
-
-        // Draw points
-        int prev_x = 0;
-        int prev_y = WINDOW_HEIGHT / 2;
-        
-        for (int x = 0; x < WINDOW_WIDTH; ++x) {
-            int16_t sample = vis_buffer[read_idx];
-            read_idx = (read_idx + 1) % VIS_BUFFER_SIZE;
-
-            // Map 16-bit sample (-32768 to 32767) to screen height
-            // Invert Y because screen Y grows downwards
-            int y = WINDOW_HEIGHT / 2 - (sample * (WINDOW_HEIGHT / 2) / 32768);
-            
-            if (x > 0) {
-                SDL_RenderDrawLine(renderer, prev_x, prev_y, x, y);
-            }
-            prev_x = x;
-            prev_y = y;
-        }
-
-        SDL_RenderPresent(renderer);
-    }
-
-    ma_device_uninit(&device);
-    SDL_DestroyRenderer(renderer);
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-    return 0;
-}

synth_engine.cpp

@@ -1,35 +0,0 @@
-#include "synth_engine.h"
-
-SynthEngine::SynthEngine(uint32_t sampleRate)
-    : _sampleRate(sampleRate),
-      _phase(0),
-      _increment(0)
-{
-    // Initialize with a default frequency
-    setFrequency(440.0f);
-}
-
-void SynthEngine::setFrequency(float freq) {
-    // Calculate the phase increment for a given frequency.
-    // The phase accumulator is a 32-bit unsigned integer (0 to 2^32 - 1).
-    // One full cycle of the accumulator represents one cycle of the waveform.
-    // increment = (frequency * 2^32) / sampleRate
-    // We use a 64-bit intermediate calculation to prevent overflow.
-    _increment = static_cast<uint32_t>((static_cast<uint64_t>(freq) << 32) / _sampleRate);
-}
-
-void SynthEngine::process(int16_t* buffer, uint32_t numFrames) {
-    for (uint32_t i = 0; i < numFrames; ++i) {
-        // 1. Advance the phase. Integer overflow automatically wraps it,
-        //    which is exactly what we want for a continuous oscillator.
-        _phase += _increment;
-
-        // 2. Generate the sample. For a sawtooth wave, the sample value is
-        //    directly proportional to the phase. We take the top 16 bits
-        //    of the 32-bit phase accumulator to get a signed 16-bit sample.
-        int16_t sample = static_cast<int16_t>(_phase >> 16);
-
-        // 3. Write the sample to the buffer.
-        buffer[i] = sample;
-    }
-}

synth_engine.h

@@ -1,45 +0,0 @@
-#ifndef SYNTH_ENGINE_H
-#define SYNTH_ENGINE_H
-
-#include <stdint.h>
-
-/**
- * @class SynthEngine
- * @brief A portable, platform-agnostic synthesizer engine.
- *
- * This class contains the core digital signal processing (DSP) logic.
- * It has no dependencies on any specific hardware, OS, or audio API.
- * It works by filling a provided buffer with 16-bit signed audio samples.
- *
- * The oscillator uses a 32-bit unsigned integer as a phase accumulator,
- * which is highly efficient and avoids floating-point math in the audio loop,
- * making it ideal for the RP2040.
- */
-class SynthEngine {
-public:
-    /**
-     * @brief Constructs the synthesizer engine.
-     * @param sampleRate The audio sample rate in Hz (e.g., 44100).
-     */
-    SynthEngine(uint32_t sampleRate);
-
-    /**
-     * @brief Fills a buffer with audio samples. This is the main audio callback.
-     * @param buffer Pointer to the output buffer to be filled.
-     * @param numFrames The number of audio frames (samples) to generate.
-     */
-    void process(int16_t* buffer, uint32_t numFrames);
-
-    /**
-     * @brief Sets the frequency of the oscillator.
-     * @param freq The frequency in Hz.
-     */
-    void setFrequency(float freq);
-
-private:
-    uint32_t _sampleRate;
-    uint32_t _phase;      // Phase accumulator for the oscillator.
-    uint32_t _increment;  // Phase increment per sample, determines frequency.
-};
-
-#endif // SYNTH_ENGINE_H