11. Networking &
Communications

#include <WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include <ScioSense_ENS160.h>
#include <Adafruit_AHTX0.h>

// --- Wi-Fi Credentials ---
const char* ssid     = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";

// --- MQTT Configuration ---
const char* mqtt_server      = "broker.hivemq.com";
const char* topic_eco2        = "nicole/monitor/eco2";
const char* topic_tvoc        = "nicole/monitor/tvoc";
const char* topic_temperature = "nicole/monitor/temperatura";

WiFiClient   espClient;
PubSubClient client(espClient);

// --- Sensor Objects ---
ScioSense_ENS160 ens160(0x53);
Adafruit_AHTX0   aht21;

// --- Wi-Fi Setup ---
void setup_wifi() {
  delay(10);
  Serial.print("\nConnecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
}

// --- MQTT Reconnect ---
void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "XIAO_C6_Nicole_";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("Connected to Broker!");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  delay(2000);
  Serial.println("=== MainESP-C6 Starting ===");

  setup_wifi();
  client.setServer(mqtt_server, 1883);

  Wire.begin(D4, D5);

  if (!aht21.begin()) {
    Serial.println("[ERROR] AHT21 not found.");
    while (1) delay(500);
  }

  if (!ens160.begin()) {
    Serial.println("[ERROR] ENS160 not found.");
    while (1) delay(500);
  }

  ens160.setMode(ENS160_OPMODE_STD);
  Serial.println("=== System ready. Reading data... ===\n");
}

void loop() {
  if (!client.connected()) reconnect();
  client.loop();

  sensors_event_t evtHum, evtTemp;
  aht21.getEvent(&evtHum, &evtTemp);

  float temperature = evtTemp.temperature;
  float humidity    = 50.0; // placeholder

  ens160.set_envdata210(
    (uint16_t)((temperature + 273.15f) * 64.0f),
    (uint16_t)(humidity * 512.0f)
  );

  if (ens160.measure(true)) {
    uint16_t eco2 = ens160.geteCO2();
    uint16_t tvoc = ens160.getTVOC();

    Serial.print("Temp:");  Serial.print(temperature); Serial.println("C");
    Serial.print("eCO2: "); Serial.print(eco2);         Serial.println(" ppm");
    Serial.print("TVOC: "); Serial.print(tvoc);         Serial.println(" ppb");

    char eco2String[10], tvocString[10], temperatureString[10];
    sprintf(eco2String,         "%d",   eco2);
    sprintf(tvocString,         "%d",   tvoc);
    sprintf(temperatureString,  "%.1f", temperature);

    client.publish(topic_eco2,        eco2String);
    client.publish(topic_tvoc,        tvocString);
    client.publish(topic_temperature, temperatureString);

    Serial.println("-> Data published to HiveMQ");
  }

  delay(2000);
}