// ─────────────────────────────────────────────────────────────────────────────
// LED + Motor + I2S Speaker — XIAO ESP32-S3
// ─────────────────────────────────────────────────────────────────────────────
//
//  LED filaments  : GPIO7  (D8)  → MOSFET gate → filaments → GND
//  Motor PWM      : GPIO4  (D3)  → MOSFET gate → motor     → GND
//  I2S DIN        : GPIO1  (D0 / A0)
//  I2S LRC        : GPIO2  (D1 / A1)
//  I2S BCLK       : GPIO3  (D2 / A2)
//
//  Library required: "AudioTools" by pschatzmann
//    Install via: Arduino IDE → Library Manager → search "AudioTools"
// ─────────────────────────────────────────────────────────────────────────────

#include "AudioTools.h"

// ── Pin definitions ───────────────────────────────────────────────────────────

#define LED_PIN       7     // GPIO7  — LED MOSFET gate (moved from GPIO5)
#define MOTOR_PIN     4     // GPIO4  — Motor MOSFET gate

#define I2S_BCLK_PIN  3     // GPIO3
#define I2S_LRC_PIN   2     // GPIO2
#define I2S_DOUT_PIN  1     // GPIO1

// ── LED breathing settings ────────────────────────────────────────────────────

const int   LED_PWM_FREQ   = 24989;   // prime, above camera flicker range
const int   LED_PWM_RES    = 8;       // 8-bit → 0–255
const int   BREATHE_MS     = 4000;    // full in-out cycle duration (ms)
//          step delay = half cycle / 255 steps
const int   LED_STEP_DELAY = BREATHE_MS / 2 / 255;

unsigned long lastLedUpdate = 0;
int brightness  = 0;
int ledStep     = 1;

// ── Motor settings ────────────────────────────────────────────────────────────

const int   MOTOR_PWM_FREQ = 20000;   // 20kHz — inaudible
const int   MOTOR_PWM_RES  = 8;       // 8-bit → 0–255

// ▼▼▼  Adjust motor speed here (0 = stopped, 255 = full) ▼▼▼
const int   MOTOR_SPEED    = 140;     // ~55% — smooth constant rotation
// ▲▲▲─────────────────────────────────────────────────────▲▲▲

// ── Audio settings ────────────────────────────────────────────────────────────

const int   SAMPLE_RATE    = 44100;
const float TONE_HZ        = 110.0;   // A2 — low, warm fundamental tone
const float TONE_VOLUME    = 0.50;    // 0.0–1.0, keep moderate for testing

// ── AudioTools objects ────────────────────────────────────────────────────────

I2SStream                      i2sOut;
SineWaveGenerator<int16_t>     sineGen;
GeneratedSoundStream<int16_t>  sineStream(sineGen);
VolumeStream                   volume(i2sOut);
StreamCopy                     copier(volume, sineStream);

AudioInfo info(SAMPLE_RATE, 2, 16);  // sample rate, stereo, 16-bit

// ─────────────────────────────────────────────────────────────────────────────

void setupLED() {
  ledcAttach(LED_PIN, LED_PWM_FREQ, LED_PWM_RES);
  ledcWrite(LED_PIN, 0);
}

void setupMotor() {
  ledcAttach(MOTOR_PIN, MOTOR_PWM_FREQ, MOTOR_PWM_RES);
  ledcWrite(MOTOR_PIN, MOTOR_SPEED);
}

void setupAudio() {
  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Warning);

  // Configure I2S output
  auto cfg          = i2sOut.defaultConfig(TX_MODE);
  cfg.pin_bck       = I2S_BCLK_PIN;
  cfg.pin_ws        = I2S_LRC_PIN;
  cfg.pin_data      = I2S_DOUT_PIN;
  cfg.copyFrom(info);
  i2sOut.begin(cfg);

  // Volume stage
  auto vcfg         = volume.defaultConfig();
  vcfg.copyFrom(info);
  volume.begin(vcfg);
  volume.setVolume(TONE_VOLUME);

  // Sine generator
  sineGen.begin(info, TONE_HZ);
  sineStream.begin(info);
}

// ── Non-blocking LED breath ───────────────────────────────────────────────────

void updateLED() {
  unsigned long now = millis();
  if (now - lastLedUpdate >= (unsigned long)LED_STEP_DELAY) {
    lastLedUpdate = now;
    ledcWrite(LED_PIN, brightness);
    brightness += ledStep;
    if (brightness >= 255) { brightness = 255; ledStep = -1; }
    if (brightness <= 0)   { brightness = 0;   ledStep =  1; }
  }
}

// ─────────────────────────────────────────────────────────────────────────────

void setup() {
  Serial.begin(115200);
  delay(500);

  setupLED();
  setupMotor();
  setupAudio();

  Serial.println("LED + Motor + Speaker running");
  Serial.print("Tone: ");   Serial.print(TONE_HZ);   Serial.println(" Hz");
  Serial.print("Motor: ");  Serial.print(MOTOR_SPEED); Serial.println(" / 255");
}

void loop() {
  copier.copy();   // feeds I2S DMA buffer — paces the loop naturally
  updateLED();     // non-blocking breath step
}