esp32+4G+MQTT如何设置订阅温度传感器的主题·
时间: 2023-05-21 22:02:02 浏览: 102
您可以使用以下代码来设置esp32 4G MQTT订阅温度传感器的主题:
#include <PubSubClient.h>
#include <WiFi.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
// Replace with your network credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
// Replace with your MQTT Broker IP address
const char* mqtt_server = "your_MQTT_BROKER_IP";
WiFiClient espClient;
PubSubClient client(espClient);
Adafruit_BME280 bme;
void setup() {
Serial.begin(115200);
delay(100);
// Connect to Wi-Fi network with SSID and password
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("WiFi connected!");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
// Connect to MQTT Broker
client.setServer(mqtt_server, 1883);
while (!client.connected()) {
Serial.println("Connecting to MQTT Broker...");
if (client.connect("ESP32Client")) {
Serial.println("Connected to MQTT Broker!");
} else {
Serial.print("Failed with state ");
Serial.print(client.state());
delay(2000);
}
}
// Initialize BME280 sensor
if (!bme.begin(0x76)) {
Serial.println("Could not find a valid BME280 sensor, check wiring!");
while (1);
}
// Subscribe to temperature sensor topic
client.subscribe("temperature_sensor");
}
void loop() {
// Check if MQTT client is connected
if (!client.connected()) {
reconnect();
}
// Read temperature from BME280 sensor
float temperature = bme.readTemperature();
// Publish temperature to MQTT Broker
char temperature_str[10];
dtostrf(temperature, 4, 2, temperature_str);
client.publish("temperature_sensor", temperature_str);
// Wait for 5 seconds
delay(5000);
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.println("Attempting MQTT connection...");
// Attempt to connect
if (client.connect("ESP32Client")) {
Serial.println("Connected to MQTT Broker!");
// Subscribe to temperature sensor topic
client.subscribe("temperature_sensor");
} else {
Serial.print("Failed with state ");
Serial.print(client.state());
delay(2000);
}
}
}