ESP8266串口通信接收来自ESP32的温湿度信息，mqtt上传阿里云的代码

以下是使用ESP8266接收来自ESP32的温湿度信息并通过MQTT上传到阿里云的示例代码。

首先，需要在ESP8266上安装MQTT库，可以使用PubSubClient库，可以在Arduino IDE中进行安装。

然后，需要连接ESP8266和ESP32，可以使用串口通信或无线通信，这里以串口通信为例。

ESP32发送温湿度信息的代码示例：

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <WiFi.h>
#include <AsyncMqttClient.h>

#define WIFI_SSID "your_ssid"
#define WIFI_PASSWORD "your_password"
#define MQTT_HOST "your_mqtt_host"
#define MQTT_PORT 1883
#define MQTT_USERNAME "your_mqtt_username"
#define MQTT_PASSWORD "your_mqtt_password"
#define MQTT_TOPIC "your_topic"

#define DHTPIN 27
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

WiFiClient wifiClient;
AsyncMqttClient mqttClient;

void connectToWifi() {
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
  }
}

void setup() {
  Serial.begin(115200);
  dht.begin();
  connectToWifi();
  mqttClient.setServer(MQTT_HOST, MQTT_PORT);
  mqttClient.setCredentials(MQTT_USERNAME, MQTT_PASSWORD);
}

void loop() {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print("°C, Humidity: ");
  Serial.print(humidity);
  Serial.println("%");

  String message = String(temperature) + "," + String(humidity);
  mqttClient.publish(MQTT_TOPIC, 0, false, message.c_str());
  delay(5000);
}

ESP8266接收并上传信息的代码示例：

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

#define WIFI_SSID "your_wifi_ssid"
#define WIFI_PASSWORD "your_wifi_password"

#define MQTT_SERVER "your_mqtt_server"
#define MQTT_PORT 1883
#define MQTT_USERNAME "your_mqtt_username"
#define MQTT_PASSWORD "your_mqtt_password"
#define MQTT_TOPIC "your_mqtt_topic"

SoftwareSerial espSerial(2, 3); // RX, TX
WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

void setup() {
  Serial.begin(115200);
  espSerial.begin(115200);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
  }

  Serial.println("Connected to WiFi");

  mqttClient.setServer(MQTT_SERVER, MQTT_PORT);
  mqttClient.setCallback(callback);
  reconnect();
}

void loop() {
  if (!mqttClient.connected()) {
    reconnect();
  }

  mqttClient.loop();
}

void reconnect() {
  while (!mqttClient.connected()) {
    Serial.print("Connecting to MQTT server...");
    if (mqttClient.connect("ESP8266-client", MQTT_USERNAME, MQTT_PASSWORD)) {
      Serial.println("connected.");
      mqttClient.subscribe(MQTT_TOPIC);
    } else {
      Serial.print("failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" retrying in 5 seconds.");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";
  
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.println("Received message: " + message);

  // 解析温湿度信息
  int index = message.indexOf(",");
  float temperature = message.substring(0, index).toFloat();
  float humidity = message.substring(index + 1).toFloat();

  // 将温湿度信息上传到阿里云
  String data = "{\"Temperature\":" + String(temperature) + ",\"Humidity\":" + String(humidity) + "}";
  espSerial.println("AT+CIPSTART=\"TCP\",\"your_aliyun_host\",your_aliyun_port");
  if (espSerial.find("OK")) {
    Serial.println("TCP connection established.");
    espSerial.println("AT+CIPSEND=" + String(data.length() + 2));
    if (espSerial.find(">")) {
      Serial.println("Sending data...");
      espSerial.println(data);
    }
  }

  delay(5000);
}

在ESP8266的串口监视器中，可以看到接收到的温湿度信息和上传到阿里云的信息。

注意：需要将代码中的“your_ssid”，“your_password”，“your_mqtt_host”，“your_mqtt_username”，“your_mqtt_password”，“your_topic”，“your_aliyun_host”和“your_aliyun_port”替换为实际的值。