Esp32_Arduino接入腾讯云笔记

ESP32是一款由乐鑫科技（Espressif Systems）推出的双核、低功耗、集成Wi-Fi和蓝牙的单芯片微控制器。它采用了Tensilica Xtensa LX6高性能处理器，具有大量的GPIO引脚、模数转换器、SPI、I2S、UART、PWM、I2C和SD卡接口等功能，可以满足各种物联网（IoT）应用的需求。由于其高度集成和低功耗特性，ESP32广泛应用于智能家居、智能城市、工业自动化、智能健康、车联网等领域。

1.1 准备

软件：Arduino IDE
硬件：esp32-dev-module

1.2 esp32_Arduino的MQTT库安装

esp32通过MQTT协议连接到物联网平台，我们需要一个mqtt client的库，帮助我们发布订阅相关的topic。我们还需要一个JSON库，帮我们解析JSON，用来序列化和反序列化物模型的JSON数据。
在工具>管理库中，查找PubSubclient、ArduinoJSON和EspMQTTclient，并安装。

1.3 MQTT连接腾讯云的相关配置

这里使用腾讯云平台，创建物联网公共实例。
(1)填写域名和端口
${productid}.iotcloud.tencentdevices.com:1883
(2)生成username和password
要注意的是username和password是在连接到云端mqtt broker的时候需要填入的，可以通过这个在线工具生成。Hmac签名算法选择【HMAC-SHA1】。
(3)填写订阅和发布的消息，可从云平台中获得。
发送的消息指令，具体数据格式可通过云端的调试功能发送一条消息进行测试。

1.4 编写代码

#include 
#include 
#include "PubSubClient.h"
#include 
DynamicJsonDocument doc(1024);

const char *ssid = "climbot";
const char *pwd  = "climbot903B";
const char *mqtt_server = "E3TGIRQYNA.iotcloud.tencentdevices.com";
const char *mqtt_username = "E3TGIRQYNA01;12010126;CT9W4;1690882370";
const char *mqtt_userpwd  = "72b711c5d7f7e1c76cfca1a785fbddfd3f744163;hmacsha1";
const char *mqtt_clientid = "E3TGIRQYNA01";
const char *mqtt_pub_topic = "$thing/up/property/E3TGIRQYNA/01";
const char *mqtt_sub_topic = "$thing/down/property/E3TGIRQYNA/01";

bool power_switch;
float longtitude; 
float latitude;   
int power_percent = 0;

#define REPORT_DATA_TEMPLATE "{\"method\":\"report\",\"clientToken\":\"00000001\",\"params\":{\"power_switch\":%d,\"GPS_Info\":{\"longtitude\":%f,\"latitude\":%f},\"_mesh_generic_power_percent\":%d}}"

WiFiClient espClient;
PubSubClient mqttclient(espClient);
long lastMsg = 0;
char report_buf[1024];

void callback(char* topic, byte* payload, unsigned int length)
{
  Serial.print("--->Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  Serial.println();
  Serial.print("payload [");
  for (int i=0;i<length;i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

//处理上位机的控制指令
  DeserializationError error = deserializeJson(doc, payload);
    // Test if parsing succeeds.
      if (error) {
        Serial.print("deserializeJson() failed: ");
        Serial.println(error.f_str());
        return;
      }else{
        if (doc["clientToken"]!="00000001") {
          if (doc["params"]["power_switch"] == 1) {
            Serial.print("Power On ");
            power_switch=1;
          } else {
            Serial.print("Power Off ");
            power_switch=0;
          }
        }
      }

}

void setup_wifi()
{
    Serial.printf("Connect to %s ", ssid);
    WiFi.begin(ssid, pwd);
    while (WiFi.status() != WL_CONNECTED) {
        Serial.printf(".");
        delay(500);
    }
    Serial.println("Connected!");
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());
}

void setup() {
    Serial.begin(115200);

    setup_wifi();

    mqttclient.setServer(mqtt_server, 1883);// connect mqtt server
    mqttclient.setCallback(callback);
    mqttclient.setKeepAlive(65535);
    while (!mqttclient.connect(mqtt_clientid, mqtt_username, mqtt_userpwd)) {
        Serial.println("mqtt connect fail, reconnect");
        delay(2000);
    }
    Serial.println("mqtt connected!");
    
    // sub topic
    boolean ret = mqttclient.subscribe(mqtt_sub_topic);
    if (ret != true) {
        Serial.printf("mqtt subscribe topic [%s] fail\n", mqtt_sub_topic);
    }
    Serial.printf("mqtt subscribe topic [%s] ok\n", mqtt_sub_topic);
}

void loop() {
    // client loop
    mqttclient.loop();

    // pub topic
    long now = millis();
    if (now - lastMsg > 10000) {
        lastMsg = now;
        memset(report_buf, 0, 1024);
        sprintf(report_buf, REPORT_DATA_TEMPLATE, power_switch,longtitude,latitude,power_percent);
        Serial.println(report_buf);
        if (++power_percent > 100) {//模拟传感器数据
            power_percent = 0;
        }
         if (++longtitude > 100) {
            longtitude = 0;
        }
          if (++latitude > 100) {
            latitude = 0;
        }
        
        if (mqttclient.publish(mqtt_pub_topic, report_buf)) {
            Serial.printf("mqtt publish topic [%s] ok\n", mqtt_pub_topic);
        } else {
            Serial.printf("mqtt publish topic [%s] fail\n", mqtt_pub_topic);
        }
    }
}

1.5 烧录和测试

点击下载按钮，待下载完成后，打开串口监视器可看到打印的数据。打开腾讯云平台可查看设备在线状态。