ESP32 SDK

This document mainly introduces how to use PubSubClient in the ESP32 project to achieve functions such as connecting, subscribing, and sending and receiving messages between the ESP32 client and WaveshareCloud.

This document will separately introduce how to connect the ESP32 client to the MQTT server via TCP port and SSL/TLS port. The connection settings for TCP port and SSL/TLS port are slightly different in the connection setup section, but the code for publishing and subscribing is the same.

Preparations

Get Connection Parameters

After logging in to WaveshareCloud and creating a usable device in the * Devices | Attribute List*, click the yellow button on the right: View Address to get the relevant information.

Example:

MqttPath: mqtt.waveshare.cloud
Port: 1883
Client ID: 052405b2
Pub Topic: Pub/10/16/052405b2
Sub Topic: Sub/10/16/052405b2

Arduino IDE

In this document, Arduino IDE is used for code editing and uploading.

Install Dependencies

Install the ESP32 development board.

Click Tools-> Board-> Board Manager. Search for ESP32 and click Install.

Install the PubSub client library.

Click Sketch-> Include Library-> Manage Libraries.... Search for PubSubClient and install PubSubClient by Nick O’Leary.

Connection Methods

Set the MQTT connection address, port, topic, and client ID.

          const char* mqtt_server = "mqtt.waveshare.cloud";
          int PORT = 1883;
          const char* ID = "052405b2";  // Define device ID
          char sub[] = "Sub/10/16/052405b2";  // MQTT subscribe topic
          char pub[] = "Pub/10/16/052405b2";  // MQTT publish topic
        

Set MQTT connection address, port, topic, and client ID.
Copy CA certificate to the local machine and load it into the code.
const char* mqtt_server = "mqtt.waveshare.cloud"; int PORT = 8883; const char* ID = "052405b2"; // Define device ID char sub[] = "Sub/10/16/052405b2"; // MQTT subscribe topic char pub[] = "Pub/10/16/052405b2"; // MQTT publish topic WiFiClientSecure espClient; // Set ESP32 to enable SSL/TLS connection
For the no-certificate method, add the following code when initializing in the setup function.
espClient.setInsecure();

Set MQTT connection address, port, topic, and client ID.
Copy CA certificate to the local machine and load it into the code.
const char* mqtt_server = "mqtt.waveshare.cloud"; int PORT = 8884; const char* ID = "052405b2"; // Define device ID char sub[] = "Sub/10/16/052405b2"; // MQTT subscribe topic char pub[] = "Pub/10/16/052405b2"; // MQTT publish topic WiFiClientSecure espClient; // Set ESP32 to enable SSL/TLS connection
Load the certificate as a string into the code.
const char* root_ca = \ "-----BEGIN CERTIFICATE-----\n" "MIID6TCCAtGgAwIBAgIJALAks3ODRL3nMA0GCSqGSIb3DQEBCwUAMIGKMQswCQYD\n" "VQQGEwJjbjELMAkGA1UECAwCZ2QxCzAJBgNVBAcMAnN6MRIwEAYDVQQKDAl3YXZl\n" "c2hhcmUxDDAKBgNVBAsMA2lvdDEdMBsGA1UEAwwUbXF0dC53YXZlc2hhcmUuY2xv\n" "dWQxIDAeBgkqhkiG9w0BCQEWEXN3YW5zaGFyZUAxNjMuYzBtMB4XDTIzMTAyNjAy\n" "MzgxMVoXDTMzMTAyMzAyMzgxMVowgYoxCzAJBgNVBAYTAmNuMQswCQYDVQQIDAJn\n" "ZDELMAkGA1UEBwwCc3oxEjAQBgNVBAoMCXdhdmVzaGFyZTEMMAoGA1UECwwDaW90\n" "MR0wGwYDVQQDDBRtcXR0LndhdmVzaGFyZS5jbG91ZDEgMB4GCSqGSIb3DQEJARYR\n" "c3dhbnNoYXJlQDE2My5jMG0wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIB\n" "AQDUoDxq2kCRWqhvFvOTOrYSwbw0LIfgN5zqxXTqU36bM0wsuPVm3to0M3A+LU7t\n" "2WEL81WIgmN4Lb8fBDCEw+O3c+7Cjv3kUvkD0RZVWQgTYWIVYV+OfvwRBSAkIXl9\n" "he8VBXJ9nLi4XcSVYKSGCXw63hOJ23EODCTeKKIzfKlwq0o5d90AOz7Yet9AMqLw\n" "WvLRFTaA0oFj3rlsoigmKVQ0QIa+Dt9GZQrmGKyu27tjR067oMLSRHQRtamSuVO/\n" "wz30S1FH0T59hA30Xc8mekQT9qkPZJeY9w7wp8w3wMqnquZpn3n1ESCKZMpJnwqJ\n" "0dip3TfyNVI0nPGmEOqKejcbAgMBAAGjUDBOMB0GA1UdDgQWBBQKOKe2XoqfgLVa\n" "2bNxZ5eeKBEMazAfBgNVHSMEGDAWgBQKOKe2XoqfgLVa2bNxZ5eeKBEMazAMBgNV\n" "HRMEBTADAQH/MA0GCSqGSIb3DQEBCwUAA4IBAQAdvB90XePwNx/KRINFwTtBj9cP\n" "VFSCWccGjQgNQoxKXKRmWoIbUAXtoVjzFAqc2t9Blcw9HNIeR5bt+Cw5AYrqnw41\n" "z+ZqJ3D6j1S+YGaAnN/8PQRDDl2/cTw/6CDf+iyVI/FPcFcMcNTFFrwII4/3V4sn\n" "OoO+7MuCHH3sEliEef+FqIiP0UKeWLlGPJLRidcc1416ksrfeHGdkBrQTJ2gZfFC\n" "j+sRHaFesqEQhDzNUpQ0bXgIivWLiPrA+dwcBp+oq4o4hpZIddDD33JaAxGkUM9B\n" "4k0kEUml0o8NWGVHPdueLq5srczFfw2AHiUPyKCje9RjPNq6TvBCG9n9aznV\n" "-----END CERTIFICATE-----"; const char* server_crt = \ "-----BEGIN CERTIFICATE-----\n" "MIIDkjCCAnoCCQDLHlw5O4wZlTANBgkqhkiG9w0BAQsFADCBijELMAkGA1UEBhMC\n" "Y24xCzAJBgNVBAgMAmdkMQswCQYDVQQHDAJzejESMBAGA1UECgwJd2F2ZXNoYXJl\n" "MQwwCgYDVQQLDANpb3QxHTAbBgNVBAMMFG1xdHQud2F2ZXNoYXJlLmNsb3VkMSAw\n" "HgYJKoZIhvcNAQkBFhFzd2Fuc2hhcmVAMTYzLmMwbTAeFw0yMzEwMjYwMjQ2NTla\n" "Fw0yNDEwMjUwMjQ2NTlaMIGKMQswCQYDVQQGEwJjbjELMAkGA1UECAwCZ2QxCzAJ\n" "BgNVBAcMAnN6MRIwEAYDVQQKDAl3YXZlc2hhcmUxDDAKBgNVBAsMA2lvdDEdMBsG\n" "A1UEAwwUbXF0dC53YXZlc2hhcmUuY2xvdWQxIDAeBgkqhkiG9w0BCQEWEXN3YW5z\n" "aGFyZUAxNjMuY29tMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA28+u\n" "XDwxDevoWHyWECp2cvOAFuttb0oBDfiwgBuJrnizn1iBlhmtxKBXjT5+L1P2aPAs\n" "AoB5boe7Q4RAwpnXi8fW7/mmh+tahtJtb3TvKEdvACbitwg6ZkwbuOv10YuI+OT3\n" "H8cOSdERm6oCXP0TtlE8T6tQ2d2CdBV34+nWLCOEjDHOBhIO43g6hC+/zIZRUOqw\n" "qQxRkryl7cBs2gqd8O964FQfC3WXtiOQoJohsWIScUQMrQ2UZ/A/Bb8gC6lJhi8C\n" "TvvJavbXP4DwU16ZRPyW2fq24xflew3yD/0bXjQCD9JhhwpCmjkE0/XHbCUrfHmD\n" "NOASvFRV/oPkPT/kHwIDAQABMA0GCSqGSIb3DQEBCwUAA4IBAQCxnd1adIlwI8Ta\n" "rKP1Ajb/4FHDYLZwqqQqD2y2/Edd2RChOFkv8MhkkKZEBToWd/5+xFDZMmOLy+/S\n" "zl2FRGMbenXTy9/IDhJioctm6+BGkRaM5OskqLnyugJr7sHqEnS9Un/aGjhxbV+4\n" "tGKXW7ZUyRwgf82sKDAZ6hdJ65d6Qe4Jp2Z19pdv0sm4mYgKir/QAuW+dnH7FEAg\n" "kR9M38iXvgTNx9vcrCztwxivvnVuFlbm2Nt17GrNusN8g6D0ipymJ16PUaUI7tk3\n" "tBSkdjFLg6NVsV2hw/7Kcvw1gOdzXs1uOrZIQbFGSHbbIgzlsWaA8S3gsw3L4YZb\n" "6efBEiLC\n" "-----END CERTIFICATE-----"; const char* server_key = \ "-----BEGIN RSA PRIVATE KEY-----\n" "MIIEogIBAAKCAQEA28+uXDwxDevoWHyWECp2cvOAFuttb0oBDfiwgBuJrnizn1iB\n" "lhmtxKBXjT5+L1P2aPAsAoB5boe7Q4RAwpnXi8fW7/mmh+tahtJtb3TvKEdvACbi\n" "twg6ZkwbuOv10YuI+OT3H8cOSdERm6oCXP0TtlE8T6tQ2d2CdBV34+nWLCOEjDHO\n" "BhIO43g6hC+/zIZRUOqwqQxRkryl7cBs2gqd8O964FQfC3WXtiOQoJohsWIScUQM\n" "rQ2UZ/A/Bb8gC6lJhi8CTvvJavbXP4DwU16ZRPyW2fq24xflew3yD/0bXjQCD9Jh\n" "hwpCmjkE0/XHbCUrfHmDNOASvFRV/oPkPT/kHwIDAQABAoIBAA4j9huI4775hiDr\n" "Itw3XxdWAs92pbubDyZO8UvMebb3nNaLYwq87CjSB8/WTVfOFvP5P1uJ2EX8BVf6\n" "kg/yxaMAYBtf/A6SXWh+8PtSknAM6F8iIUOVC+y4yK/EvjOUvmMEl8E7lPe6s19I\n" "OI6y2SnJYA/f/XuGfHXrS6Mlz9lW8RKd4r4KmvNgkyy2Yt21zec5bB7aJVuC9MV5\n" "+6f20S/EHbbAi1YbOPtcPOaoIkdtXO5PuSwFy8HER5jYOQp+RUT5xC8HoS+jJCF9\n" "5dCa9suSiw3vq0cNn91AIx+oU4lVrCNcVpX41aKsovk4wwuaOFinQqTN5k6xLNPq\n" "M+yrZgECgYEA7bKgW1EgCRK5M/WZZTQbTSW7iWVZanrccotyxIkYzGpgmQy8AYKj\n" "n2rpyeBXLwcBHPqdsWPVYSeEJJ9zbHxsBRxsX7MLvB5zRb0S05YVk0+x3YvDXhCy\n" "42MHcPPjxWDvRh16j1h+IwRsIpatQrZnnKBXAGc/w4jVLZ2sV43imH8CgYEA7Lx8\n" "PA/x9mSxBrjBIIpKQBlAcBzxT6z82AiDBfOG4Sf/P2fb/wNSRKVC/XeTh1Zczt1Z\n" "ovPJdVe8qGsqEaI54Zrhp2shGfkvTTh4WwI3km8jdcEtjtHaoUBYFzmFd+Rrv8Uj\n" "PWV5cfPmxbWG7GY9j6gudHgZE6iZLO1JtwPt5GECgYAfPvbzahOi/bIY0XUrp5Db\n" "MFWZtxfs9l+aMxiQG1GGNYmjNNhV/n1RzHUVE4eCaBJOY+ds1SnMjqxBQDClFyn/\n" "9f+NCPVG8l3G0hbyd204oyZHcELrT5ikaXUl9PmBDcAGYIOm6kQSiFdKqLH37hBq\n" "t20YYXoxUwBq8aohDEa4MwKBgBVgl99cmT7krM+sk1P66OWM4jK9ilTljBd9/Ubm\n" "TMG8OOJi4IzQofcs7TWyPJI2DD9p4ZRDa2e7OoAC3VOmUI+8yq+xjtWnmMviU4v0\n" "UUxZ2NvjS9ffv1xcURgXy6Od7tTsWlhK94KAwdAMqlhiiyCT0U4XIjySNvLFoqhy\n" "JGNBAoGAL/S8MY/eSrOwndafr/Oa+lHd7obuM9MuUsLzswhSJBZqnKAb+XGZCnEm\n" "I8hTk2hQm68nrKpw8121rqvWejHmkUzKlZJ45ixokfj3TOktzcxb5/kGfvRnRuzG\n" "nNwCNDQdC+lEfyiEoi8nuDEM0pR3emSWiUvI6QDDfER19psF62c=\n" "-----END RSA PRIVATE KEY-----";
Certificate initialization settings
espClient.setCACert(root_ca); espClient.setCertificate(server_crt); espClient.setPrivateKey(server_key);

Subscribe to Topic

client.subscribe(<Data>);

Message callback

void callback(char* topic, byte* payload, unsigned int length) {
  String inputString;
  for (int i = 0; i < length; i++) {
    inputString += (char)payload[i];
  }
  Serial.println(inputString);
  int dataBegin = inputString.indexOf("\"data\"");
  if (dataBegin == -1) {
    Serial.println(F("Missing 'data' field in JSON."));
    return;
  }
  int builtInBegin = inputString.indexOf("\"builtIn\"", dataBegin);
  if (builtInBegin == -1) {
    Serial.println(F("Missing 'builtIn' field in 'data' object."));
    return;
  }
  int valueBegin = inputString.indexOf(':', builtInBegin);
  int valueEnd = inputString.indexOf('}', valueBegin);
  if (valueBegin == -1 || valueEnd == -1) {
    Serial.println(F("Invalid 'builtIn' value."));
    return;
  }
  String builtInValueStr = inputString.substring(valueBegin + 1, valueEnd);
  int builtInValue = builtInValueStr.toInt();
  if (builtInValue == 0) {
    Serial.println("close!");
  } else {
    Serial.println("open!");
  }
}

Publishing topics

Release a message

client.publish(pub, <data>);

Json upload function

void sendJsonData() {
  sendJson["ID"] = ID;
  String pubres;
  serializeJson(sendJson, pubres);
  int str_len = pubres.length() + 1;
  char char_array[str_len];
  pubres.toCharArray(char_array, str_len);
  client.publish(pub, char_array);
}

Complete code

Connect via a TCP port

#include <ArduinoJson.h>
#include <Arduino.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>

#define MSG_BUFFER_SIZE (50)

#define STASSID ""
#define STAPSK ""

const char* mqtt_server = "mqtt.waveshare.cloud";
int PORT = 1883;

const char* ID = "";  
char sub[] = "";  
char pub[] = "";  



StaticJsonDocument<400> sendJson;
StaticJsonDocument<400> readJson;
unsigned long lastUpdateTime = 0;
const char* ssid = STASSID;
const char* password = STAPSK;
char msg[MSG_BUFFER_SIZE];
WiFiClient espClient;

PubSubClient client(espClient);

const unsigned long updateInterval = 5000;

void setup() {
  Serial.begin(9600);
  setup_wifi();
  client.setServer(mqtt_server, PORT);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  if (millis() - lastUpdateTime > updateInterval) {  
    sendJsonData();
    lastUpdateTime = millis();
  }
}
void callback(char* topic, byte* payload, unsigned int length) {
  String inputString;
  for (int i = 0; i < length; i++) {
    inputString += (char)payload[i];
  }
  Serial.println(inputString);
  int dataBegin = inputString.indexOf("\"data\"");
  if (dataBegin == -1) {
    Serial.println(F("Missing 'data' field in JSON."));
    return;
  }
  int builtInBegin = inputString.indexOf("\"builtIn\"", dataBegin);
  if (builtInBegin == -1) {
    Serial.println(F("Missing 'builtIn' field in 'data' object."));
    return;
  }
  int valueBegin = inputString.indexOf(':', builtInBegin);
  int valueEnd = inputString.indexOf('}', valueBegin);
  if (valueBegin == -1 || valueEnd == -1) {
    Serial.println(F("Invalid 'builtIn' value."));
    return;
  }
  String builtInValueStr = inputString.substring(valueBegin + 1, valueEnd);
  int builtInValue = builtInValueStr.toInt();
  if (builtInValue == 0) {
    Serial.println("close!");
  } else {
    Serial.println("open!");
  }
}

void setup_wifi() {
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect(ID)) {
      client.subscribe(sub);
    } else {
      Serial.print(client.state());
      delay(5000);
    }
  }
}
void sendJsonData() {
  sendJson["ID"] = ID;
  String pubres;
  serializeJson(sendJson, pubres);
  int str_len = pubres.length() + 1;
  char char_array[str_len];
  pubres.toCharArray(char_array, str_len);
  client.publish(pub, char_array);
}

Connect over SSL/TSL ports (certificateless)

#include <ArduinoJson.h>
#include <Arduino.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>

#define MSG_BUFFER_SIZE (50)

#define STASSID ""
#define STAPSK ""

const char* mqtt_server = "mqtt.waveshare.cloud";
int PORT = 8883;

const char* ID = ""; 
char sub[] = "";  
char pub[] = "";  



StaticJsonDocument<400> sendJson;
StaticJsonDocument<400> readJson;
unsigned long lastUpdateTime = 0;
const char* ssid = STASSID;
const char* password = STAPSK;
char msg[MSG_BUFFER_SIZE];
WiFiClient espClient;

PubSubClient client(espClient);

const unsigned long updateInterval = 5000;

void setup() {
  Serial.begin(9600);
  setup_wifi();
  espClient.setInsecure(); 
  client.setServer(mqtt_server, PORT);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  if (millis() - lastUpdateTime > updateInterval) {  
    sendJsonData();
    lastUpdateTime = millis();
  }
}
void callback(char* topic, byte* payload, unsigned int length) {
  String inputString;
  for (int i = 0; i < length; i++) {
    inputString += (char)payload[i];
  }
  Serial.println(inputString);
  int dataBegin = inputString.indexOf("\"data\"");
  if (dataBegin == -1) {
    Serial.println(F("Missing 'data' field in JSON."));
    return;
  }
  int builtInBegin = inputString.indexOf("\"builtIn\"", dataBegin);
  if (builtInBegin == -1) {
    Serial.println(F("Missing 'builtIn' field in 'data' object."));
    return;
  }
  int valueBegin = inputString.indexOf(':', builtInBegin);
  int valueEnd = inputString.indexOf('}', valueBegin);
  if (valueBegin == -1 || valueEnd == -1) {
    Serial.println(F("Invalid 'builtIn' value."));
    return;
  }
  String builtInValueStr = inputString.substring(valueBegin + 1, valueEnd);
  int builtInValue = builtInValueStr.toInt();
  if (builtInValue == 0) {
    Serial.println("close!");
  } else {
    Serial.println("open!");
  }
}

void setup_wifi() {
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect(ID)) {
      client.subscribe(sub);
    } else {
      Serial.print(client.state());
      delay(5000);
    }
  }
}
void sendJsonData() {
  sendJson["ID"] = ID;
  String pubres;
  serializeJson(sendJson, pubres);
  int str_len = pubres.length() + 1;
  char char_array[str_len];
  pubres.toCharArray(char_array, str_len);
  client.publish(pub, char_array);
}

Connect via SSL/TSL port (with certificate)

#include <ArduinoJson.h>
#include <Arduino.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>

#define MSG_BUFFER_SIZE (50)

#define STASSID ""
#define STAPSK ""

const char* mqtt_server = "mqtt.waveshare.cloud";
int PORT = 8884;

const char* ID = ""; 
char sub[] = ""; 
char pub[] = ""; 



StaticJsonDocument<400> sendJson;
StaticJsonDocument<400> readJson;
unsigned long lastUpdateTime = 0;
const char* ssid = STASSID;
const char* password = STAPSK;
char msg[MSG_BUFFER_SIZE];

WiFiClientSecure espClient; 
PubSubClient client(espClient);

const unsigned long updateInterval = 5000;

const char* root_ca = \
  "-----BEGIN CERTIFICATE-----\n"
  "MIID6TCCAtGgAwIBAgIJALAks3ODRL3nMA0GCSqGSIb3DQEBCwUAMIGKMQswCQYD\n"
  "VQQGEwJjbjELMAkGA1UECAwCZ2QxCzAJBgNVBAcMAnN6MRIwEAYDVQQKDAl3YXZl\n"
  "c2hhcmUxDDAKBgNVBAsMA2lvdDEdMBsGA1UEAwwUbXF0dC53YXZlc2hhcmUuY2xv\n"
  "dWQxIDAeBgkqhkiG9w0BCQEWEXN3YW5zaGFyZUAxNjMuYzBtMB4XDTIzMTAyNjAy\n"
  "MzgxMVoXDTMzMTAyMzAyMzgxMVowgYoxCzAJBgNVBAYTAmNuMQswCQYDVQQIDAJn\n"
  "ZDELMAkGA1UEBwwCc3oxEjAQBgNVBAoMCXdhdmVzaGFyZTEMMAoGA1UECwwDaW90\n"
  "MR0wGwYDVQQDDBRtcXR0LndhdmVzaGFyZS5jbG91ZDEgMB4GCSqGSIb3DQEJARYR\n"
  "c3dhbnNoYXJlQDE2My5jMG0wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIB\n"
  "AQDUoDxq2kCRWqhvFvOTOrYSwbw0LIfgN5zqxXTqU36bM0wsuPVm3to0M3A+LU7t\n"
  "2WEL81WIgmN4Lb8fBDCEw+O3c+7Cjv3kUvkD0RZVWQgTYWIVYV+OfvwRBSAkIXl9\n"
  "he8VBXJ9nLi4XcSVYKSGCXw63hOJ23EODCTeKKIzfKlwq0o5d90AOz7Yet9AMqLw\n"
  "WvLRFTaA0oFj3rlsoigmKVQ0QIa+Dt9GZQrmGKyu27tjR067oMLSRHQRtamSuVO/\n"
  "wz30S1FH0T59hA30Xc8mekQT9qkPZJeY9w7wp8w3wMqnquZpn3n1ESCKZMpJnwqJ\n"
  "0dip3TfyNVI0nPGmEOqKejcbAgMBAAGjUDBOMB0GA1UdDgQWBBQKOKe2XoqfgLVa\n"
  "2bNxZ5eeKBEMazAfBgNVHSMEGDAWgBQKOKe2XoqfgLVa2bNxZ5eeKBEMazAMBgNV\n"
  "HRMEBTADAQH/MA0GCSqGSIb3DQEBCwUAA4IBAQAdvB90XePwNx/KRINFwTtBj9cP\n"
  "VFSCWccGjQgNQoxKXKRmWoIbUAXtoVjzFAqc2t9Blcw9HNIeR5bt+Cw5AYrqnw41\n"
  "z+ZqJ3D6j1S+YGaAnN/8PQRDDl2/cTw/6CDf+iyVI/FPcFcMcNTFFrwII4/3V4sn\n"
  "OoO+7MuCHH3sEliEef+FqIiP0UKeWLlGPJLRidcc1416ksrfeHGdkBrQTJ2gZfFC\n"
  "j+sRHaFesqEQhDzNUpQ0bXgIivWLiPrA+dwcBp+oq4o4hpZIddDD33JaAxGkUM9B\n"
  "4k0kEUml0o8NWGVHPdueLq5srczFfw2AHiUPyKCje9RjPNq6TvBCG9n9aznV\n"
  "-----END CERTIFICATE-----";

const char* server_crt  = \
  "-----BEGIN CERTIFICATE-----\n"
  "MIIDkjCCAnoCCQDLHlw5O4wZlTANBgkqhkiG9w0BAQsFADCBijELMAkGA1UEBhMC\n"
  "Y24xCzAJBgNVBAgMAmdkMQswCQYDVQQHDAJzejESMBAGA1UECgwJd2F2ZXNoYXJl\n"
  "MQwwCgYDVQQLDANpb3QxHTAbBgNVBAMMFG1xdHQud2F2ZXNoYXJlLmNsb3VkMSAw\n"
  "HgYJKoZIhvcNAQkBFhFzd2Fuc2hhcmVAMTYzLmMwbTAeFw0yMzEwMjYwMjQ2NTla\n"
  "Fw0yNDEwMjUwMjQ2NTlaMIGKMQswCQYDVQQGEwJjbjELMAkGA1UECAwCZ2QxCzAJ\n"
  "BgNVBAcMAnN6MRIwEAYDVQQKDAl3YXZlc2hhcmUxDDAKBgNVBAsMA2lvdDEdMBsG\n"
  "A1UEAwwUbXF0dC53YXZlc2hhcmUuY2xvdWQxIDAeBgkqhkiG9w0BCQEWEXN3YW5z\n"
  "aGFyZUAxNjMuY29tMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA28+u\n"
  "XDwxDevoWHyWECp2cvOAFuttb0oBDfiwgBuJrnizn1iBlhmtxKBXjT5+L1P2aPAs\n"
  "AoB5boe7Q4RAwpnXi8fW7/mmh+tahtJtb3TvKEdvACbitwg6ZkwbuOv10YuI+OT3\n"
  "H8cOSdERm6oCXP0TtlE8T6tQ2d2CdBV34+nWLCOEjDHOBhIO43g6hC+/zIZRUOqw\n"
  "qQxRkryl7cBs2gqd8O964FQfC3WXtiOQoJohsWIScUQMrQ2UZ/A/Bb8gC6lJhi8C\n"
  "TvvJavbXP4DwU16ZRPyW2fq24xflew3yD/0bXjQCD9JhhwpCmjkE0/XHbCUrfHmD\n"
  "NOASvFRV/oPkPT/kHwIDAQABMA0GCSqGSIb3DQEBCwUAA4IBAQCxnd1adIlwI8Ta\n"
  "rKP1Ajb/4FHDYLZwqqQqD2y2/Edd2RChOFkv8MhkkKZEBToWd/5+xFDZMmOLy+/S\n"
  "zl2FRGMbenXTy9/IDhJioctm6+BGkRaM5OskqLnyugJr7sHqEnS9Un/aGjhxbV+4\n"
  "tGKXW7ZUyRwgf82sKDAZ6hdJ65d6Qe4Jp2Z19pdv0sm4mYgKir/QAuW+dnH7FEAg\n"
  "kR9M38iXvgTNx9vcrCztwxivvnVuFlbm2Nt17GrNusN8g6D0ipymJ16PUaUI7tk3\n"
  "tBSkdjFLg6NVsV2hw/7Kcvw1gOdzXs1uOrZIQbFGSHbbIgzlsWaA8S3gsw3L4YZb\n"
  "6efBEiLC\n"
  "-----END CERTIFICATE-----";

const char* server_key  = \
"-----BEGIN RSA PRIVATE KEY-----\n"
"MIIEogIBAAKCAQEA28+uXDwxDevoWHyWECp2cvOAFuttb0oBDfiwgBuJrnizn1iB\n"
"lhmtxKBXjT5+L1P2aPAsAoB5boe7Q4RAwpnXi8fW7/mmh+tahtJtb3TvKEdvACbi\n"
"twg6ZkwbuOv10YuI+OT3H8cOSdERm6oCXP0TtlE8T6tQ2d2CdBV34+nWLCOEjDHO\n"
"BhIO43g6hC+/zIZRUOqwqQxRkryl7cBs2gqd8O964FQfC3WXtiOQoJohsWIScUQM\n"
"rQ2UZ/A/Bb8gC6lJhi8CTvvJavbXP4DwU16ZRPyW2fq24xflew3yD/0bXjQCD9Jh\n"
"hwpCmjkE0/XHbCUrfHmDNOASvFRV/oPkPT/kHwIDAQABAoIBAA4j9huI4775hiDr\n"
"Itw3XxdWAs92pbubDyZO8UvMebb3nNaLYwq87CjSB8/WTVfOFvP5P1uJ2EX8BVf6\n"
"kg/yxaMAYBtf/A6SXWh+8PtSknAM6F8iIUOVC+y4yK/EvjOUvmMEl8E7lPe6s19I\n"
"OI6y2SnJYA/f/XuGfHXrS6Mlz9lW8RKd4r4KmvNgkyy2Yt21zec5bB7aJVuC9MV5\n"
"+6f20S/EHbbAi1YbOPtcPOaoIkdtXO5PuSwFy8HER5jYOQp+RUT5xC8HoS+jJCF9\n"
"5dCa9suSiw3vq0cNn91AIx+oU4lVrCNcVpX41aKsovk4wwuaOFinQqTN5k6xLNPq\n"
"M+yrZgECgYEA7bKgW1EgCRK5M/WZZTQbTSW7iWVZanrccotyxIkYzGpgmQy8AYKj\n"
"n2rpyeBXLwcBHPqdsWPVYSeEJJ9zbHxsBRxsX7MLvB5zRb0S05YVk0+x3YvDXhCy\n"
"42MHcPPjxWDvRh16j1h+IwRsIpatQrZnnKBXAGc/w4jVLZ2sV43imH8CgYEA7Lx8\n"
"PA/x9mSxBrjBIIpKQBlAcBzxT6z82AiDBfOG4Sf/P2fb/wNSRKVC/XeTh1Zczt1Z\n"
"ovPJdVe8qGsqEaI54Zrhp2shGfkvTTh4WwI3km8jdcEtjtHaoUBYFzmFd+Rrv8Uj\n"
"PWV5cfPmxbWG7GY9j6gudHgZE6iZLO1JtwPt5GECgYAfPvbzahOi/bIY0XUrp5Db\n"
"MFWZtxfs9l+aMxiQG1GGNYmjNNhV/n1RzHUVE4eCaBJOY+ds1SnMjqxBQDClFyn/\n"
"9f+NCPVG8l3G0hbyd204oyZHcELrT5ikaXUl9PmBDcAGYIOm6kQSiFdKqLH37hBq\n"
"t20YYXoxUwBq8aohDEa4MwKBgBVgl99cmT7krM+sk1P66OWM4jK9ilTljBd9/Ubm\n"
"TMG8OOJi4IzQofcs7TWyPJI2DD9p4ZRDa2e7OoAC3VOmUI+8yq+xjtWnmMviU4v0\n"
"UUxZ2NvjS9ffv1xcURgXy6Od7tTsWlhK94KAwdAMqlhiiyCT0U4XIjySNvLFoqhy\n"
"JGNBAoGAL/S8MY/eSrOwndafr/Oa+lHd7obuM9MuUsLzswhSJBZqnKAb+XGZCnEm\n"
"I8hTk2hQm68nrKpw8121rqvWejHmkUzKlZJ45ixokfj3TOktzcxb5/kGfvRnRuzG\n"
"nNwCNDQdC+lEfyiEoi8nuDEM0pR3emSWiUvI6QDDfER19psF62c=\n"
"-----END RSA PRIVATE KEY-----";



void setup() {
  Serial.begin(9600);
  setup_wifi();
  // espClient.setInsecure(); 
  espClient.setCACert(root_ca);
  espClient.setCertificate(server_crt);
  espClient.setPrivateKey(server_key);
  client.setServer(mqtt_server, PORT);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  if (millis() - lastUpdateTime > updateInterval) { 
    sendJsonData();
    lastUpdateTime = millis();
  }
}
void callback(char* topic, byte* payload, unsigned int length) {
  String inputString;
  for (int i = 0; i < length; i++) {
    inputString += (char)payload[i];
  }
  Serial.println(inputString);
  int dataBegin = inputString.indexOf("\"data\"");
  if (dataBegin == -1) {
    Serial.println(F("Missing 'data' field in JSON."));
    return;
  }
  int builtInBegin = inputString.indexOf("\"builtIn\"", dataBegin);
  if (builtInBegin == -1) {
    Serial.println(F("Missing 'builtIn' field in 'data' object."));
    return;
  }
  int valueBegin = inputString.indexOf(':', builtInBegin);
  int valueEnd = inputString.indexOf('}', valueBegin);
  if (valueBegin == -1 || valueEnd == -1) {
    Serial.println(F("Invalid 'builtIn' value."));
    return;
  }
  String builtInValueStr = inputString.substring(valueBegin + 1, valueEnd);
  int builtInValue = builtInValueStr.toInt();
  if (builtInValue == 0) {
    Serial.println("close!");
  } else {
    Serial.println("open!");
  }
}

void setup_wifi() {
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect(ID)) {
      client.subscribe(sub);
    } else {
      Serial.print(client.state());
      delay(5000);
    }
  }
}
void sendJsonData() {
  sendJson["ID"] = ID;
  String pubres;
  serializeJson(sendJson, pubres);
  int str_len = pubres.length() + 1;
  char char_array[str_len];
  pubres.toCharArray(char_array, str_len);
  client.publish(pub, char_array);
}

Last modified: 12 一月 2024