双色温摄影补光灯

// ============================================================
//  Photography Fill Light Controller
//  Board  : ESP32-S3 DevKitC-1
//  Power  : 2S 18650 (7.4V) via MP2762A NVDC charger
//  PD     : HUSB238 negotiates USB-C PD (asks for 20V)
//  LED    : Two PWM Buck CC drivers — warm 3000K + cool 5600K
//  UI     : KY-040 rotary encoder + SSD1306 0.96" OLED (I2C)
//  Fan    : 5V fan via N-MOSFET, speed tracks brightness
// ============================================================

#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "Adafruit_HUSB238.h"

// ── Pin definitions ──────────────────────────────────────────
#define PIN_ENC_CLK   40
#define PIN_ENC_DT    41
#define PIN_ENC_SW    42
#define PIN_PWM_WARM  14
#define PIN_PWM_COOL  21
#define PIN_FAN       38

// ── LEDC (ESP32 hardware PWM) channels ───────────────────────
#define CH_WARM  0
#define CH_COOL  1
#define CH_FAN   2
#define PWM_FREQ 25000   // 25 kHz – inaudible, good for CC modules
#define PWM_BITS 10      // 1024 steps

// ── OLED ──────────────────────────────────────────────────────
#define OLED_W    128
#define OLED_H    64
#define OLED_ADDR 0x3C

// Forward declarations
static void applyLED();
static void drawDisplay();
void IRAM_ATTR encoderISR();

Adafruit_SSD1306 display(OLED_W, OLED_H, &Wire, -1);

// ── HUSB238 ───────────────────────────────────────────────────
Adafruit_HUSB238 pd;

// ── State ─────────────────────────────────────────────────────
// UI modes: 0 = adjust brightness, 1 = adjust colour temp (CCT)
uint8_t  uiMode       = 0;
int16_t  brightness   = 80;   // 0–100%
int16_t  cct          = 50;   // 0 = full warm, 100 = full cool
bool     lightsOn     = true;

// Encoder state
volatile int8_t  encDelta     = 0;
volatile uint8_t encLastState = 0;

// Debounce
unsigned long swLastMs = 0;
bool          swWasPressed = false;

// Display dirty flag
bool displayDirty = true;

// ── Helpers ───────────────────────────────────────────────────
static void applyLED() {
    if (!lightsOn) {
        ledcWrite(CH_WARM, 0);
        ledcWrite(CH_COOL, 0);
        ledcWrite(CH_FAN,  0);
        return;
    }

    // Scale brightness (0-100) to PWM duty (0-1023)
    float bScale = brightness / 100.0f;

    // CCT: 0% warm only, 100% cool only, 50% equal blend
    float wFrac = 1.0f - (cct / 100.0f);
    float cFrac = cct / 100.0f;

    uint16_t warmDuty = (uint16_t)(bScale * wFrac * 1023);
    uint16_t coolDuty = (uint16_t)(bScale * cFrac * 1023);

    // Fan speed roughly tracks brightness (min 20% when on)
    uint16_t fanDuty  = (uint16_t)((0.20f + 0.80f * bScale) * 1023);

    ledcWrite(CH_WARM, warmDuty);
    ledcWrite(CH_COOL, coolDuty);
    ledcWrite(CH_FAN,  fanDuty);
}

static void drawDisplay() {
    display.clearDisplay();

    // ── Title / power source indicator ───────────────────────
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print(lightsOn ? "FILL LIGHT  ON" : "FILL LIGHT OFF");

    // ── Brightness bar ────────────────────────────────────────
    display.setCursor(0, 14);
    display.print("BRI ");
    display.print(brightness);
    display.print("%");
    if (uiMode == 0) {
        display.print(" <");  // active field indicator
    }
    // Draw bar
    int barW = (brightness * 100) / 100;  // maps 0-100 to 0-100 px
    display.fillRect(0,  25, barW, 6, SSD1306_WHITE);
    display.drawRect(0,  25, 100,  6, SSD1306_WHITE);

    // ── CCT bar ───────────────────────────────────────────────
    display.setCursor(0, 35);
    int cctK = 3000 + (int)((cct / 100.0f) * 2600);  // 3000-5600 K
    display.print("CCT ");
    display.print(cctK);
    display.print("K");
    if (uiMode == 1) {
        display.print(" <");  // active field indicator
    }
    // Draw bar: left = warm, right = cool
    display.fillRect(0, 46, cct, 6, SSD1306_WHITE);  // filled = cool portion
    display.drawRect(0, 46, 100, 6, SSD1306_WHITE);

    // ── W/C split label ──────────────────────────────────────
    display.setCursor(0, 56);
    display.print("W");
    int warmPct = 100 - cct;
    int coolPct = cct;
    display.print(warmPct);
    display.print("%  C");
    display.print(coolPct);
    display.print("%");

    display.display();
}

// ── Encoder ISR ───────────────────────────────────────────────
void IRAM_ATTR encoderISR() {
    uint8_t clk = digitalRead(PIN_ENC_CLK);
    uint8_t dt  = digitalRead(PIN_ENC_DT);
    uint8_t cur = (clk << 1) | dt;
    if (cur != encLastState) {
        if (encLastState == 0b10 && cur == 0b00) encDelta++;
        if (encLastState == 0b01 && cur == 0b00) encDelta--;
        encLastState = cur;
    }
}

// ── Setup ─────────────────────────────────────────────────────
void setup() {
    Serial.begin(115200);

    // LEDC PWM
    ledcSetup(CH_WARM, PWM_FREQ, PWM_BITS);
    ledcSetup(CH_COOL, PWM_FREQ, PWM_BITS);
    ledcSetup(CH_FAN,  PWM_FREQ, PWM_BITS);
    ledcAttachPin(PIN_PWM_WARM, CH_WARM);
    ledcAttachPin(PIN_PWM_COOL, CH_COOL);
    ledcAttachPin(PIN_FAN,      CH_FAN);

    // Encoder
    pinMode(PIN_ENC_CLK, INPUT_PULLUP);
    pinMode(PIN_ENC_DT,  INPUT_PULLUP);
    pinMode(PIN_ENC_SW,  INPUT_PULLUP);
    encLastState = (digitalRead(PIN_ENC_CLK) << 1) | digitalRead(PIN_ENC_DT);
    attachInterrupt(digitalPinToInterrupt(PIN_ENC_CLK), encoderISR, CHANGE);
    attachInterrupt(digitalPinToInterrupt(PIN_ENC_DT),  encoderISR, CHANGE);

    // I2C
    Wire.begin(8, 9);   // SDA=GPIO8, SCL=GPIO9

    // OLED
    if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
        Serial.println("SSD1306 init failed");
    }
    display.clearDisplay();
    display.display();

    // HUSB238 – negotiate 20V for maximum power
    if (pd.begin(0x08, &Wire)) {
        Serial.println("HUSB238 found, requesting 20V PD...");
        pd.selectVoltage(PD_20V);
    } else {
        Serial.println("HUSB238 not found (DC input assumed)");
    }

    applyLED();
    drawDisplay();
}

// ── Loop ──────────────────────────────────────────────────────
void loop() {
    // --- Encoder delta (atomic read) ---
    noInterrupts();
    int8_t delta = encDelta;
    encDelta = 0;
    interrupts();

    if (delta != 0) {
        if (uiMode == 0) {
            brightness = constrain(brightness + delta, 0, 100);
        } else {
            cct = constrain(cct + delta, 0, 100);
        }
        applyLED();
        displayDirty = true;
    }

    // --- Button (debounced) ---
    bool swPressed = (digitalRead(PIN_ENC_SW) == LOW);
    unsigned long now = millis();
    if (swPressed && !swWasPressed && (now - swLastMs > 50)) {
        swLastMs = now;
        // Short press < 600 ms: switch mode
        // Long press ≥ 600 ms: toggle on/off (handled on release)
    }
    if (!swPressed && swWasPressed) {
        unsigned long held = now - swLastMs;
        if (held < 600) {
            uiMode = 1 - uiMode;  // toggle brightness / CCT
        } else {
            lightsOn = !lightsOn;
            applyLED();
        }
        displayDirty = true;
    }
    swWasPressed = swPressed;

    // --- Display update (only when state changed) ---
    if (displayDirty) {
        drawDisplay();
        displayDirty = false;
    }

    delay(10);  // ~100 Hz poll, keeps ISR happy
}