使用esp32-doit-dev-v1开发板，测试mqtt协议, 发布（publish）到onenet 平台。
注意：
1.使用的mqtt arduino 客户端是 pubsubclient 库。其默认是ESP8266, 所以例子例包换文件“Wifi8266.h”，可以改为"Wifi.h"就可以。
2.关键是按照mqtt的onenet文档，编制payload数据包。其具体格式有多种类型。调试的是最简单的type3， json数据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"
*/
//改为<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 = "热点ssid";
const char* password = "连接密码";
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 = "设备_id";
//clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect("设备id","产品_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("设备Id","产品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);
}
}