AI Pet Safety Collar

#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_NeoPixel.h>
#include <driver/i2s.h>

#define I2C_SDA 8
#define I2C_SCL 9
#define MODEM_RX 44
#define MODEM_TX 43
#define MODEM_PWRKEY 16
#define SOS_PIN 4
#define LED_PIN 5
#define BUZZER_PIN 6
#define I2S_BCLK 12
#define I2S_WS 11
#define I2S_DATA 13


// Forward declarations
void setStatus(uint32_t color);
void alertTone(uint16_t ms);
void emitEvent(const char *type, const char *detail);
void writeReg(uint8_t addr, uint8_t reg, uint8_t value);
bool readBytes(uint8_t addr, uint8_t reg, uint8_t *out, size_t n);
float readAccelerationG();
uint32_t microphoneEnergy();
void printModem();

static const uint8_t MPU_ADDR = 0x68;
static const uint8_t MAX30102_ADDR = 0x57;
Adafruit_NeoPixel pixel(1, LED_PIN, NEO_GRB + NEO_KHZ800);
HardwareSerial modem(1);
uint32_t lastMotionMs = 0, lastGnssMs = 0, loudSinceMs = 0;
bool sosActive = false;

void setStatus(uint32_t color) { pixel.setPixelColor(0, color); pixel.show(); }
void alertTone(uint16_t ms) { ledcAttach(BUZZER_PIN, 2000, 8); ledcWriteTone(BUZZER_PIN, 2000); delay(ms); ledcWriteTone(BUZZER_PIN, 0); }
void emitEvent(const char *type, const char *detail) {
  Serial.printf("{\"event\":\"%s\",\"detail\":\"%s\",\"uptime_s\":%lu}\n", type, detail, millis() / 1000UL);
  modem.print("AT+CGNSSINFO\r\n");
}
void writeReg(uint8_t addr, uint8_t reg, uint8_t value) {
  Wire.beginTransmission(addr); Wire.write(reg); Wire.write(value); Wire.endTransmission();
}
bool readBytes(uint8_t addr, uint8_t reg, uint8_t *out, size_t n) {
  Wire.beginTransmission(addr); Wire.write(reg);
  if (Wire.endTransmission(false) != 0) return false;
  if (Wire.requestFrom((int)addr, (int)n) != n) return false;
  for (size_t i = 0; i < n; ++i) out[i] = Wire.read();
  return true;
}
float readAccelerationG() {
  uint8_t b[6];
  if (!readBytes(MPU_ADDR, 0x3B, b, sizeof(b))) return -1.0f;
  int16_t ax = (b[0] << 8) | b[1], ay = (b[2] << 8) | b[3], az = (b[4] << 8) | b[5];
  float x = ax / 16384.0f, y = ay / 16384.0f, z = az / 16384.0f;
  return sqrtf(x * x + y * y + z * z);
}
uint32_t microphoneEnergy() {
  int32_t samples[256]; size_t bytesRead = 0;
  i2s_read(I2S_NUM_0, samples, sizeof(samples), &bytesRead, 30 / portTICK_PERIOD_MS);
  uint32_t count = bytesRead / sizeof(int32_t); if (!count) return 0;
  uint64_t total = 0;
  for (uint32_t i = 0; i < count; ++i) total += abs(samples[i] >> 14);
  return (uint32_t)(total / count);
}
void printModem() {
  while (modem.available()) {
    String line = modem.readStringUntil('\n'); line.trim();
    if (line.startsWith("+CGNSSINFO:")) Serial.printf("{\"gnss\":\"%s\"}\n", line.c_str());
  }
}
void setup() {
  Serial.begin(115200);
  pinMode(SOS_PIN, INPUT_PULLUP); pinMode(MODEM_PWRKEY, OUTPUT); digitalWrite(MODEM_PWRKEY, HIGH);
  pixel.begin(); setStatus(pixel.Color(0, 0, 20));
  Wire.begin(I2C_SDA, I2C_SCL); Wire.setClock(400000);
  writeReg(MPU_ADDR, 0x6B, 0x00);
  writeReg(MAX30102_ADDR, 0x09, 0x03);
  modem.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
  delay(500); modem.print("AT\r\n"); modem.print("AT+CGNSSPWR=1\r\n");
  i2s_config_t config = {};
  config.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX); config.sample_rate = 16000;
  config.bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT; config.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT;
  config.communication_format = I2S_COMM_FORMAT_STAND_I2S; config.dma_buf_count = 4; config.dma_buf_len = 128;
  i2s_pin_config_t pins = {};
  pins.bck_io_num = I2S_BCLK; pins.ws_io_num = I2S_WS; pins.data_out_num = I2S_PIN_NO_CHANGE; pins.data_in_num = I2S_DATA;
  i2s_driver_install(I2S_NUM_0, &config, 0, NULL); i2s_set_pin(I2S_NUM_0, &pins);
  emitEvent("boot", "collar prototype started");
}
void loop() {
  printModem();
  if (digitalRead(SOS_PIN) == LOW && !sosActive) {
    sosActive = true; setStatus(pixel.Color(255, 0, 0)); alertTone(300); emitEvent("sos", "manual SOS button pressed");
  }
  if (digitalRead(SOS_PIN) == HIGH) sosActive = false;
  if (millis() - lastMotionMs >= 250) {
    lastMotionMs = millis(); float g = readAccelerationG();
    if (g > 2.8f) { setStatus(pixel.Color(255, 80, 0)); alertTone(100); emitEvent("impact", "high acceleration event"); }
    if (g > 0 && g < 0.18f) emitEvent("possible_fall", "near-free-fall acceleration detected");
    uint8_t prox[2];
    if (readBytes(MAX30102_ADDR, 0xFF, prox, 2) && ((prox[0] << 8) | prox[1]) < 200) Serial.println("{\"health\":\"heart sensor lacks skin contact\"}");
  }
  uint32_t energy = microphoneEnergy();
  if (energy > 1100 && !loudSinceMs) loudSinceMs = millis();
  if (energy <= 1100 && loudSinceMs) {
    if (millis() - loudSinceMs > 10000) emitEvent("abnormal_sound_candidate", "sustained loud sound; trained dog-audio model required for diagnosis");
    loudSinceMs = 0;
  }
  if (millis() - lastGnssMs >= 60000) { lastGnssMs = millis(); modem.print("AT+CGNSSINFO\r\n"); }
  if (!sosActive) setStatus(pixel.Color(0, 10, 0));
}