ESP32 OLED 第一屏：显示传感器数值和异常状态

arduino-cli lib install --no-deps 'Sensirion Core@0.7.3'
arduino-cli lib install --no-deps 'Sensirion I2C SHT4x@1.1.2'
arduino-cli lib install --no-deps 'Adafruit BusIO@1.17.4'
arduino-cli lib install --no-deps 'Adafruit GFX Library@1.12.4'
arduino-cli lib install --no-deps 'Adafruit SSD1306@2.5.17'

// SPDX-License-Identifier: MIT
// D01: DevKitC-1 v1.1 N8R8; Adafruit PID326 + PID4885, 3.3V I2C.
#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <SensirionI2cSht4x.h>
#include <freertos/FreeRTOS.h>
#include <freertos/queue.h>
#include <freertos/task.h>
#include <math.h>

constexpr uint8_t SDA_PIN = 8, SCL_PIN = 9, BUTTON_PIN = 5;
constexpr uint8_t OLED_ADDRESS = 0x3D;
constexpr uint32_t SAMPLE_MS = 2000, FRAME_MS = 500, STALE_MS = 5000;
Adafruit_SSD1306 screen(128, 64, &Wire, -1, 100000UL, 100000UL);
SensirionI2cSht4x sensor;
struct Snapshot {
  bool busReady, screenAck, screenReady, valid;
  uint8_t page;
  int16_t sensorError;
  uint32_t samples, frames, lastGoodAt, frameDuration;
  float temperature, humidity;
};
void drawFrame(const Snapshot &s, uint32_t now);
QueueHandle_t pageQueue = nullptr, snapshotQueue = nullptr;
bool uiTaskReady = false;

uint8_t probe(uint8_t address) {
  Wire.beginTransmission(address);
  return Wire.endTransmission(true);
}
void drawFrame(const Snapshot &s, uint32_t now) {
  screen.clearDisplay();
  screen.setTextColor(SSD1306_WHITE);
  screen.setTextSize(1);
  screen.setCursor(0, 0);
  screen.print(s.page == 0 ? "D01  SHT40" : "D01  DIAGNOSTICS");
  screen.drawLine(0, 10, 127, 10, SSD1306_WHITE);
  screen.setCursor(0, 15);
  if (!s.valid) {
    screen.println(s.sensorError != 0 ? "SENSOR ERROR" : "STALE / NO SAMPLE");
    screen.println("T: -- C");
    screen.println("RH: -- %");
  } else if (s.page == 0) {
    screen.print("T: "); screen.print(s.temperature, 1); screen.println(" C");
    screen.print("RH: "); screen.print(s.humidity, 1); screen.println(" %");
    screen.print("age: "); screen.print(uint32_t(now - s.lastGoodAt)); screen.println(" ms");
  } else {
    screen.print("samples: "); screen.println(s.samples);
    screen.print("frames: "); screen.println(s.frames);
    screen.print("last TX: "); screen.print(s.frameDuration); screen.println(" ms");
  }
  screen.setCursor(0, 56);
  screen.print("button GPIO5: page "); screen.print(s.page);
  screen.display();  // synchronous I2C, isolated in this worker task
}
void i2cUiTask(void *) {
  Snapshot s{};
  s.temperature = s.humidity = NAN;
  s.busReady = Wire.begin(SDA_PIN, SCL_PIN, 100000);
  Wire.setTimeOut(20);
  sensor.begin(Wire, SHT40_I2C_ADDR_44);
  uint32_t sampledAt = millis() - SAMPLE_MS;
  uint32_t framedAt = millis() - FRAME_MS, busTriedAt = millis();
  for (;;) {
    uint32_t now = millis();
    uint8_t page;
    if (xQueueReceive(pageQueue, &page, 0) == pdTRUE) s.page = page;
    if (!s.busReady && uint32_t(now - busTriedAt) >= SAMPLE_MS) {
      busTriedAt = now;
      s.busReady = Wire.begin(SDA_PIN, SCL_PIN, 100000);
      Wire.setTimeOut(20);
    }
    if (uint32_t(now - sampledAt) >= SAMPLE_MS) {
      sampledAt = now;
      ++s.samples;
      float temperature = NAN, humidityRaw = NAN;
      s.sensorError = s.busReady ? sensor.measureHighPrecision(temperature, humidityRaw) : -1;
      s.valid = s.sensorError == 0 && isfinite(temperature) && isfinite(humidityRaw);
      if (s.sensorError == 0 && !s.valid) s.sensorError = -2;
      if (s.valid) {
        s.temperature = temperature;
        s.humidity = fminf(100.0f, fmaxf(0.0f, humidityRaw));
        s.lastGoodAt = millis();
      } else {
        s.temperature = s.humidity = NAN;  // no stale number rendered as current
      }
    }
    now = millis();
    if (s.valid && uint32_t(now - s.lastGoodAt) > STALE_MS) s.valid = false;
    if (uint32_t(now - framedAt) >= FRAME_MS) {
      framedAt = now;
      s.screenAck = s.busReady && probe(OLED_ADDRESS) == 0;
      if (!s.screenAck) s.screenReady = false;
      if (s.screenAck && !s.screenReady) {
        // PID326 auto-reset revision: no reset pin. Wire is already configured.
        s.screenReady = screen.begin(SSD1306_SWITCHCAPVCC, OLED_ADDRESS, false, false);
      }
      if (s.screenAck && s.screenReady) {
        const uint32_t startedAt = millis();
        drawFrame(s, startedAt);
        s.frameDuration = millis() - startedAt;
        ++s.frames;  // submitted, not optically verified or I2C payload-ack verified
      }
      xQueueOverwrite(snapshotQueue, &s);
    }
    vTaskDelay(pdMS_TO_TICKS(5));
  }
}
void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pageQueue = xQueueCreate(1, sizeof(uint8_t));
  snapshotQueue = xQueueCreate(1, sizeof(Snapshot));
  if (pageQueue && snapshotQueue)
    uiTaskReady = xTaskCreate(i2cUiTask, "d01-i2c", 8192, nullptr, 1, nullptr) == pdPASS;
  Serial.printf("D01 core=3.3.12 task=%u OLED=128x64@0x3D SDA=8 SCL=9 100kHz\n", uiTaskReady);
}
void loop() {
  static bool initialized = false, candidate, stable;
  static uint8_t page = 0;
  static uint32_t changedAt = 0, presses = 0, reportedAt = 0, lastLoopAt = 0, maxGap = 0;
  const uint32_t now = millis();
  const bool raw = digitalRead(BUTTON_PIN);
  if (!initialized) {
    initialized = true; candidate = stable = raw; changedAt = lastLoopAt = now;
  }
  const uint32_t gap = now - lastLoopAt;
  lastLoopAt = now;
  if (gap > maxGap) maxGap = gap;
  if (raw != candidate) { candidate = raw; changedAt = now; }
  if (candidate != stable && uint32_t(now - changedAt) >= 30) {
    stable = candidate;
    if (stable == LOW) {
      page ^= 1;
      if (uiTaskReady) xQueueOverwrite(pageQueue, &page);
      Serial.printf("BUTTON press=%lu accepted=%lu page=%u task=%u\n",
        (unsigned long)++presses, (unsigned long)now, page, uiTaskReady);
    }
  }
  if (uint32_t(now - reportedAt) >= 2000) {
    reportedAt = now;
    Snapshot s{};
    if (uiTaskReady && xQueuePeek(snapshotQueue, &s, 0) == pdTRUE) {
      Serial.printf("UI bus=%u oled_ack=%u allocated=%u valid=%u sensor_error=%d page=%u samples=%lu frames_submitted=%lu last_tx_ms=%lu max_input_gap_ms=%lu\n",
        s.busReady, s.screenAck, s.screenReady, s.valid, s.sensorError, s.page,
        (unsigned long)s.samples, (unsigned long)s.frames, (unsigned long)s.frameDuration, (unsigned long)maxGap);
    } else Serial.printf("UI unavailable task=%u; input still runs\n", uiTaskReady);
    maxGap = 0;
  }
  delay(1);
}

arduino-cli compile --fqbn 'esp32:esp32:esp32s3:FlashSize=8M,PSRAM=opi,FlashMode=qio,PartitionScheme=default_8MB,CDCOnBoot=default,USBMode=hwcdc' examples/esp32/esp32-oled-first-display
arduino-cli upload --fqbn 'esp32:esp32:esp32s3:FlashSize=8M,PSRAM=opi,FlashMode=qio,PartitionScheme=default_8MB,CDCOnBoot=default,USBMode=hwcdc' -p PORT --upload-property upload.speed=115200 examples/esp32/esp32-oled-first-display
arduino-cli monitor -p PORT --config baudrate=115200