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楼主 |
发表于 2021-3-9 15:34:56
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这里使用esp8266进行远程控制。前提已经搭建好mqtt服务器。

下面是emqx官方代码,稍微改动了一下,注释详细。使用只需要将对应的pin针脚接继电器控制针脚即可,通过发送1或者0进行控制,发送首字符不为1的为HIGH。
里面还有一下冗余代码,懒得删了,也可以给大家参考。
- /*
- 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"
- */
- #include <ESP8266WiFi.h>
- #include <PubSubClient.h>
- // Update these with values suitable for your network.
- const char* ssid = "***"; //wifi名称
- const char* password = "***"; //wifi密码
- const char* mqtt_server = "***"; //自己服务器ip
- WiFiClient espClient;
- PubSubClient client(espClient);
- unsigned long lastMsg = 0;
- #define MSG_BUFFER_SIZE (50)
- char msg[MSG_BUFFER_SIZE];
- int value = 0;
- void setup_wifi() {
- delay(10);
- // We start by connecting to a WiFi network
- 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(".");
- }
- 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
- //在对应主题输入,若输入信息首字符为‘1’则设BUILTIN_LED为LOW,否则设为HIGH
- 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 = "ESP8266Client-";
- clientId += String(random(0xffff), HEX);
- // Attempt to connect
- if (client.connect(clientId.c_str(), "用户名", "用户密码")) {
- //emqx_auth_username开启后,需要加入用户名和密码,若没有开启可以直接使用client.connect(clientId.c_str())
- Serial.println("connected");
- // Once connected, publish an announcement...
- client.publish("outTopic", "hello world");
- // ... and resubscribe
- client.subscribe("inTopic"); //订阅主题‘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,这里将BUILTIN_LED换成控制继电器的针脚即可
- Serial.begin(115200);
- setup_wifi();
- client.setServer(mqtt_server, 1883);
- client.setCallback(callback);
- }
- void loop() {
- if (!client.connected()) {
- reconnect();
- }
- client.loop();
-
- unsigned long now = millis();
- if (now - lastMsg > 10000) {
- lastMsg = now;
- int LEDState = digitalRead(BUILTIN_LED);//读取继电器状态
- ++value;
- snprintf (msg, MSG_BUFFER_SIZE, "LEDState #%ld", LEDState);
- Serial.print("Publish message: ");
- Serial.println(msg);
- client.publish("outTopic", msg); // 将继电器状态发送到主题outTopic
- }
- }
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