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76 lines
2.2 KiB
C++

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include "DHT.h"
// WiFi
const char *ssid = "mousse"; // Enter your WiFi name
const char *password = "qweqweqwe"; // Enter WiFi password
// MQTT Broker
const char *mqtt_broker = "broker.emqx.io";
const char *topic = "temp_hum/kunming";
const char *mqtt_username = "emqx";
const char *mqtt_password = "public";
const int mqtt_port = 1883;
// DHT11
#define DHTPIN D4
#define DHTTYPE DHT11 // DHT 11
unsigned long previousMillis = 0;
WiFiClient espClient;
PubSubClient client(espClient);
DHT dht(DHTPIN, DHTTYPE);
void setup() {
// Set software serial baud to 115200;
Serial.begin(115200);
// connecting to a WiFi network
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.println("Connecting to WiFi..");
}
Serial.println("Connected to the WiFi network");
//connecting to a mqtt broker
client.setServer(mqtt_broker, mqtt_port);
client.setCallback(callback);
//connecting to a mqtt broker
while (!client.connected()) {
String client_id = "esp8266-client-";
client_id += String(WiFi.macAddress());
Serial.printf("The client %s connects to the public mqtt broker\n", client_id.c_str());
if (client.connect(client_id, mqtt_username, mqtt_password)) {
Serial.println("Public emqx mqtt broker connected");
} else {
Serial.print("failed with state ");
Serial.print(client.state());
delay(2000);
}
}
// dht11 begin
dht.begin();
}
void loop() {
client.loop();
unsigned long currentMillis = millis();
// temperature and humidity data are publish every five second
if (currentMillis - previousMillis >= 5000) {
previousMillis = currentMillis;
float temp = dht.readTemperature();
float hum = dht.readHumidity();
// json serialize
DynamicJsonDocument data(256);
data["temp"] = temp;
data["hum"] = hum;
// publish temperature and humidity
char json_string[256];
serializeJson(data, json_string);
// {"temp":23.5,"hum":55}
Serial.println(json_string);
client.publish(topic, json_string, false);
}
}