DHT22 MQTT ESP8266

main.cpp

#include <Adafruit_Sensor.h>
// DHT Temperature & Humidity Sensor
// Unified Sensor Library Example
// Written by Tony DiCola for Adafruit Industries
// Released under an MIT license.

// REQUIRES the following Arduino libraries:
// - DHT Sensor Library: https://github.com/adafruit/DHT-sensor-library
// - Adafruit Unified Sensor Lib: https://github.com/adafruit/Adafruit_Sensor

#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>

#include <ESP8266WiFi.h>
#include <PubSubClient.h>

const char *SSID = "";
const char *PSK = "";
const char *MQTT_BROKER = "";

#define DHTPIN 5 // Digital pin connected to the DHT sensor
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// Uncomment the type of sensor in use:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

// See guide for details on sensor wiring and usage:
//   https://learn.adafruit.com/dht/overview

DHT_Unified dht(DHTPIN, DHTTYPE);

uint32_t delayMS;

WiFiClient espClient;
PubSubClient client(espClient);

long lastMsg = 0;
char msg[50];
int value = 0;

void setup_wifi()
{
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(SSID);

  //WiFi.mode(WIFI_STA);
  WiFi.begin(SSID, PSK);

  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect()
{
  while (!client.connected())
  {
    Serial.print("Reconnecting...");
    if (!client.connect("ESP8266Client", "", ""))
    {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying in 5 seconds");
      delay(5000);
    }
  }
}

void setup()
{
  Serial.begin(9600);
  // Initialize device.
  dht.begin();
  setup_wifi();
  client.setServer(MQTT_BROKER, 1883);

  Serial.println(F("DHTxx Unified Sensor Example"));
  // Print temperature sensor details.
  sensor_t sensor;
  dht.temperature().getSensor(&sensor);
  Serial.println(F("------------------------------------"));
  Serial.println(F("Temperature Sensor"));
  Serial.print(F("Sensor Type: "));
  Serial.println(sensor.name);
  Serial.print(F("Driver Ver:  "));
  Serial.println(sensor.version);
  Serial.print(F("Unique ID:   "));
  Serial.println(sensor.sensor_id);
  Serial.print(F("Max Value:   "));
  Serial.print(sensor.max_value);
  Serial.println(F("°C"));
  Serial.print(F("Min Value:   "));
  Serial.print(sensor.min_value);
  Serial.println(F("°C"));
  Serial.print(F("Resolution:  "));
  Serial.print(sensor.resolution);
  Serial.println(F("°C"));
  Serial.println(F("------------------------------------"));
  // Print humidity sensor details.
  dht.humidity().getSensor(&sensor);
  Serial.println(F("Humidity Sensor"));
  Serial.print(F("Sensor Type: "));
  Serial.println(sensor.name);
  Serial.print(F("Driver Ver:  "));
  Serial.println(sensor.version);
  Serial.print(F("Unique ID:   "));
  Serial.println(sensor.sensor_id);
  Serial.print(F("Max Value:   "));
  Serial.print(sensor.max_value);
  Serial.println(F("%"));
  Serial.print(F("Min Value:   "));
  Serial.print(sensor.min_value);
  Serial.println(F("%"));
  Serial.print(F("Resolution:  "));
  Serial.print(sensor.resolution);
  Serial.println(F("%"));
  Serial.println(F("------------------------------------"));
  // Set delay between sensor readings based on sensor details.
  delayMS = 30 * sensor.min_delay / 1000;
}

void loop()
{
  // Connect to MQTT
  if (!client.connected())
  {
    reconnect();
  }
  client.loop();
  // Get temperature event and print its value.
  sensors_event_t event;
  dht.temperature().getEvent(&event);
  if (isnan(event.temperature))
  {
    Serial.println(F("Error reading temperature!"));
  }
  else
  {
    Serial.print(F("Temperature: "));
    Serial.print(event.temperature);
    Serial.println(F("°C"));
    snprintf(msg, 50, "%*.1f", event.temperature);
    Serial.print("Publish message: ");
    Serial.println(msg);
    client.publish("/home/grannyflat/temperature", msg);
  }
  // Get humidity event and print its value.
  dht.humidity().getEvent(&event);
  if (isnan(event.relative_humidity))
  {
    Serial.println(F("Error reading humidity!"));
  }
  else
  {
    Serial.print(F("Humidity: "));
    Serial.print(event.relative_humidity);
    Serial.println(F("%"));
    snprintf(msg, 50, "%*.1f", event.relative_humidity);
    Serial.print("Publish message: ");
    Serial.println(msg);
    client.publish("/home/grannyflat/humidity", msg);
  }
  ESP.deepSleep(delayMS);
}