Text
platformio.ini
src/main.cpp

Ini
[env:esp32-s3-wroom-1-n8r2]
platform = espressif32@^6.7.0
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.flash_size = 8MB
board_build.psram_type = opi
board_build.arduino.memory_type = qio_opi
build_flags =
  -DARDUINO_USB_MODE=1
  -DARDUINO_USB_CDC_ON_BOOT=1
lib_deps =
  sparkfun/SparkFun MAX3010x Pulse and Proximity Sensor Library@^1.1.2
  adafruit/Adafruit TMP117@^1.1.0
  adafruit/Adafruit Unified Sensor@^1.1.14
  mikalhart/TinyGPSPlus@^1.1.0

Cpp
#include <Arduino.h>
#include <Wire.h>
#include <SparkFun_MAX3010x.h>
#include <Adafruit_TMP117.h>
#include <Adafruit_Sensor.h>
#include <TinyGPSPlus.h>
#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>
#include <driver/i2s.h>
#include <math.h>

namespace Pins {
constexpr int SDA = 8, SCL = 9;
constexpr int HR_INT = 10, IMU_INT = 11;
constexpr int GPS_RX = 18, GPS_TX = 17;
constexpr int MIC_BCLK = 4, MIC_WS = 5, MIC_DATA = 6;
}
constexpr uint32_t I2C_HZ = 400000;
constexpr uint32_t GPS_BAUD = 9600;
constexpr uint8_t BMI270_ADDR = 0x68;
constexpr uint8_t BMI270_CHIP_ID_REG = 0x00;
constexpr uint8_t BMI270_EXPECTED_ID = 0x24;

MAX30105 ppg;
Adafruit_TMP117 tmp117;
TinyGPSPlus gps;
HardwareSerial gpsUart(1);
BLECharacteristic *telemetry = nullptr;
bool ppgOK = false, tmpOK = false, bmiOK = false, bleConnected = false;
uint32_t lastReport = 0;

class ServerCallbacks : public BLEServerCallbacks {
  void onConnect(BLEServer*) override { bleConnected = true; }
  void onDisconnect(BLEServer*) override {
    bleConnected = false;
    BLEDevice::startAdvertising();
  }
};

bool readReg8(uint8_t addr, uint8_t reg, uint8_t &value) {
  Wire.beginTransmission(addr);
  Wire.write(reg);
  if (Wire.endTransmission(false) != 0) return false;
  if (Wire.requestFrom(addr, (uint8_t)1) != 1) return false;
  value = Wire.read();
  return true;
}

void initBLE() {
  BLEDevice::init("PetCollar");
  BLEServer *server = BLEDevice::createServer();
  server->setCallbacks(new ServerCallbacks());
  BLEService *service = server->createService("7c010000-6d2c-4bda-9b53-6fd94c0f1000");
  telemetry = service->createCharacteristic(
      "7c010001-6d2c-4bda-9b53-6fd94c0f1000",
      BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_NOTIFY);
  telemetry->addDescriptor(new BLE2902());
  telemetry->setValue("boot");
  service->start();
  BLEAdvertising *adv = BLEDevice::getAdvertising();
  adv->addServiceUUID(service->getUUID());
  adv->setScanResponse(true);
  BLEDevice::startAdvertising();
}

bool initI2S() {
  i2s_config_t cfg{};
  cfg.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX);
  cfg.sample_rate = 16000;
  cfg.bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT;
  cfg.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT;
  cfg.communication_format = I2S_COMM_FORMAT_STAND_I2S;
  cfg.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1;
  cfg.dma_buf_count = 4;
  cfg.dma_buf_len = 128;
  cfg.use_apll = false;
  cfg.tx_desc_auto_clear = false;
  cfg.fixed_mclk = 0;
  i2s_pin_config_t pins{};
  pins.bck_io_num = Pins::MIC_BCLK;
  pins.ws_io_num = Pins::MIC_WS;
  pins.data_out_num = I2S_PIN_NO_CHANGE;
  pins.data_in_num = Pins::MIC_DATA;
  return i2s_driver_install(I2S_NUM_0, &cfg, 0, nullptr) == ESP_OK &&
         i2s_set_pin(I2S_NUM_0, &pins) == ESP_OK;
}

uint32_t readMicLevel() {
  int32_t samples[128];
  size_t bytes = 0;
  if (i2s_read(I2S_NUM_0, samples, sizeof(samples), &bytes,
               pdMS_TO_TICKS(20)) != ESP_OK) return 0;
  const size_t count = bytes / sizeof(samples[0]);
  uint64_t sum = 0;
  for (size_t i = 0; i < count; ++i) {
    int32_t s = samples[i] >> 14; // 18-bit SPH0645 sample in 32-bit slot
    sum += (uint32_t)abs(s);
  }
  return count ? (uint32_t)(sum / count) : 0;
}

void initSensors() {
  Wire.begin(Pins::SDA, Pins::SCL, I2C_HZ);
  pinMode(Pins::HR_INT, INPUT_PULLUP);
  pinMode(Pins::IMU_INT, INPUT);

  ppgOK = ppg.begin(Wire, I2C_SPEED_FAST);
  if (ppgOK) {
    ppg.setup(0x1F, 4, 2, 100, 411, 4096); // power, avg, red+IR, rate, width, range
  }
  tmpOK = tmp117.begin(0x48, &Wire);

  uint8_t chipId = 0;
  bmiOK = readReg8(BMI270_ADDR, BMI270_CHIP_ID_REG, chipId) &&
          chipId == BMI270_EXPECTED_ID;
  // Production motion firmware must load Bosch's BMI270 configuration blob and
  // configure accel/gyro/INT1. This starter deliberately performs a safe,
  // compilable chip-ID transaction rather than embedding a version-ambiguous blob.

  Serial.printf("MAX30102=%s TMP117=%s BMI270=%s\n",
                ppgOK ? "OK" : "FAIL", tmpOK ? "OK" : "FAIL",
                bmiOK ? "ID_OK" : "FAIL");
}

void serviceGPS() {
  while (gpsUart.available()) gps.encode(gpsUart.read());
}

void report() {
  float tempC = NAN;
  sensors_event_t event{};
  if (tmpOK && tmp117.getEvent(&event)) tempC = event.temperature;
  uint32_t red = ppgOK ? ppg.getRed() : 0;
  uint32_t ir = ppgOK ? ppg.getIR() : 0;
  uint32_t mic = readMicLevel();

  char payload[220];
  if (gps.location.isValid()) {
    snprintf(payload, sizeof(payload),
      "{\"tC\":%.2f,\"red\":%lu,\"ir\":%lu,\"mic\":%lu,\"bmi\":%s,\"lat\":%.6f,\"lon\":%.6f,\"sat\":%lu}",
      tempC, (unsigned long)red, (unsigned long)ir, (unsigned long)mic,
      bmiOK ? "true" : "false", gps.location.lat(), gps.location.lng(),
      (unsigned long)gps.satellites.value());
  } else {
    snprintf(payload, sizeof(payload),
      "{\"tC\":%.2f,\"red\":%lu,\"ir\":%lu,\"mic\":%lu,\"bmi\":%s,\"gps\":false}",
      tempC, (unsigned long)red, (unsigned long)ir, (unsigned long)mic,
      bmiOK ? "true" : "false");
  }
  Serial.println(payload);
  telemetry->setValue((uint8_t*)payload, strlen(payload));
  if (bleConnected) telemetry->notify();
}

void setup() {
  Serial.begin(115200); // native USB CDC because ARDUINO_USB_CDC_ON_BOOT=1
  const uint32_t deadline = millis() + 3000;
  while (!Serial && millis() < deadline) delay(10);
  Serial.println("Smart Pet Collar boot");
  initSensors();
  gpsUart.begin(GPS_BAUD, SERIAL_8N1, Pins::GPS_RX, Pins::GPS_TX);
  Serial.printf("I2S=%s\n", initI2S() ? "OK" : "FAIL");
  initBLE();
}

void loop() {
  serviceGPS();
  if (millis() - lastReport >= 1000) {
    lastReport = millis();
    report();
  }
  delay(2);
}

Bash
pio run
pio run -t upload
pio device monitor

• Integrate Bosch BMI270 Sensor API/configuration blob, configure ranges/ODR and map INT1 to GPIO11.
• Add PPG signal-quality, animal-contact detection, validated heart-rate algorithm, calibration and fault limits.
• Add BLE security/bonding, privacy, authenticated updates, unique device identity and production-test commands.
• Add low-power states, watchdog, brownout/reset logging, battery/charger telemetry strategy, and data retention policy.
• Freeze dependency versions and archive a clean pio run log with the released firmware binary/hash.