使用esp32-Arduino+PubSubClient+mqtt 上傳數據到中移動OneNet

使用esp32-doit-dev-v1開發板，測試mqtt協議, 發布（publish）到onenet 平台。
注意：
1.使用的mqtt arduino 客戶端是 pubsubclient 庫。其默認是ESP8266, 所以例子例包換文件“Wifi8266.h”，可以改為"Wifi.h"就可以。
2.關鍵是按照mqtt的onenet文檔，編制payload數據包。其具體格式有多種類型。調試的是最簡單的type3， json數據2 形式。

/*
 Basic ESP8266 MQTT example

 This sketch demonstrates the capabilities of the pubsub library in combination
 with the ESP8266 board/library.

 It connects to an MQTT server then:
  - publishes "hello world" to the topic "outTopic" every two seconds
  - subscribes to the topic "inTopic", printing out any messages
    it receives. NB - it assumes the received payloads are strings not binary
  - If the first character of the topic "inTopic" is an 1, switch ON the ESP Led,
    else switch it off

 It will reconnect to the server if the connection is lost using a blocking
 reconnect function. See the 'mqtt_reconnect_nonblocking' example for how to
 achieve the same result without blocking the main loop.

 To install the ESP8266 board, (using Arduino 1.6.4+):
  - Add the following 3rd party board manager under "File -> Preferences -> Additional Boards Manager URLs":
       http://arduino.esp8266.com/stable/package_esp8266com_index.json
  - Open the "Tools -> Board -> Board Manager" and click install for the ESP8266"
  - Select your ESP8266 in "Tools -> Board"

*/
//改為<WiFi.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

//#define BUILTIN_LED 2

// Update these with values suitable for your network.

const char* ssid = "熱點ssid";
const char* password = "連接密碼";
const char* mqtt_server = "183.230.40.39";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg_buf[200];
int value = 0;  //
//char one_type3_header[] = {'0x03','0x00','0x46'};
char dataTemplete[]="{"temperature":25.5,"time":%d}";
char msgJson[75];
char debug_buf[200];
int i;
unsigned short json_len=0;
uint8_t* packet_p;
uint8_t debug_buffer_start_index = 0;


void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

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

  // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '1') {
    digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
    // but actually the LED is on; this is because
    // it is active low on the ESP-01)
  } else {
    digitalWrite(BUILTIN_LED, HIGH);  // Turn the LED off by making the voltage HIGH
  }

}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    //String clientId = "設備_id";
    //clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect("設備id","產品_id","API_key")) {  //One net user name as product ID , and password as APIKey
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("outTopic", "hello world");
      // ... and resubscribe
      client.subscribe("inTopic");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output, where do it esp32 get gpio2 as led
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 6002);  //not 1883 , one net use the port of 6002 as mqtt server
  client.connect("設備Id","產品id","API_key");
  client.setCallback(callback);
}

void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  long now = millis();
  if (now - lastMsg > 2000) {
    lastMsg = now;
    ++value;
    //snprintf (msgJson, 75, "hello world #%ld", value);
    snprintf(msgJson,40,dataTemplete,22);
    json_len=strlen(msgJson); //packet length count the end char '\0'
    msg_buf[0]=char(0x03);  //palyLoad packet byte 1, one_net mqtt Publish packet payload byte 1, type3 , json type2 
    msg_buf[1]=char(json_len>>8);  //high 8 bits of json_len (16bits as short int type)
    msg_buf[2]=char(json_len&0xff); //low 8 bits of json_len (16bits as short int type)
   // snprintf(msg_buf+3,40,dataTemplete,value);
  
   memcpy(msg_buf+3,msgJson,strlen(msgJson));
   msg_buf[3+strlen(msgJson)] = 0;
    Serial.print("Publish message: ");
    Serial.println(msgJson);
    client.publish("$dp",msg_buf,3+strlen(msgJson),false); // msg_buf as payload length which may have a "0x00"byte
    
    //debug one_net packet
    packet_p = client.getBufferPointer();
    for(i = 0 ; i< 200;i++)
    {
     //sprintf(debug_buf,"0x%02x ",msg_buf[i]);
     sprintf(debug_buf,"0x%02x ",packet_p[i]);
     Serial.print(debug_buf);
    }
    Serial.println();
    for(i = 0 ; i< 200;i++)
    {
     sprintf(debug_buf,"0x%02x ",msg_buf[i]);
     //sprintf(debug_buf,"0x%02x ",packet_p[i]);
     Serial.print(debug_buf);
    }
    Serial.println();
    debug_buffer_start_index=client.getDebugVar();
    Serial.println(debug_buffer_start_index);
  }
}