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{{Tuto Step | {{Tuto Step | ||
|Step_Title=<translate>Prepare an MQTT Broker</translate> | |Step_Title=<translate>Prepare an MQTT Broker</translate> | ||
− | |Step_Content=<translate>Before we begin, we need to ensure you have an MQTT broker to communicate and test with. We can download [https://mqttx.app/ MQTTX] to ensure communication. | + | |Step_Content=<translate>Before we begin, we need to ensure you have an MQTT (Message Queuing Telemetry Transport) broker to communicate and test with. We can download [https://mqttx.app/ MQTTX](the front-end broker) to ensure communication. MQTT is a lightweight messaging protocol designed for efficient communication between devices in low-bandwidth, high-latency networks. It uses a publish-subscribe model, which we will go over later. |
<br /></translate> | <br /></translate> |
Author Sid | Last edit 10/02/2024 by Disisid
ESP32_DHT22_IFTTT_306268167_427924746149632_7414040424516888266_n.jpg Creation
Introduction & Goals:
This project utilizes the Wifi module on an ESP32 along with the PubSub library on the Arduino IDE to communicate with other IoT devices. In this specific tutorial, we learn how to communicate with your personal device and how to communicate back to the ESP32
GOALS:
Before we begin, we need to ensure you have an MQTT (Message Queuing Telemetry Transport) broker to communicate and test with. We can download MQTTX(the front-end broker) to ensure communication. MQTT is a lightweight messaging protocol designed for efficient communication between devices in low-bandwidth, high-latency networks. It uses a publish-subscribe model, which we will go over later.
Ensure that the ESP32 dev library is installed, then go to libraries in the Arduino IDE and download PubSubClient. PubSub, short for Publish/Subscribe, is a messaging pattern where senders (publishers) distribute messages to receivers (subscribers) without directly communicating with them. Publishers send messages to a central hub (broker), which then distributes them to all interested subscribers based on their topic subscriptions.
Copy the full code into your IDE. Feel free to change things like the text it prints, etc
1 #include <WiFi.h>
2 #include <PubSubClient.h>
3
4 // WiFi
5 const char *ssid = "xxxxx"; // Enter your Wi-Fi name
6 const char *password = "xxxxx"; // Enter Wi-Fi password
7
8 // MQTT Broker
9 const char *mqtt_broker = "broker.emqx.io";
10 const char *topic = "emqx/esp32";
11 const char *mqtt_username = "emqx";
12 const char *mqtt_password = "public";
13 const int mqtt_port = 1883;
14
15 WiFiClient espClient;
16 PubSubClient client(espClient);
17
18 void setup() {
19 // Set software serial baud to 115200;
20 Serial.begin(115200);
21 // Connecting to a WiFi network
22 WiFi.begin(ssid, password);
23 while (WiFi.status() != WL_CONNECTED) {
24 delay(500);
25 Serial.println("Connecting to WiFi..");
26 }
27 Serial.println("Connected to the Wi-Fi network");
28 //connecting to a mqtt broker
29 client.setServer(mqtt_broker, mqtt_port);
30 client.setCallback(callback);
31 while (!client.connected()) {
32 String client_id = "esp32-client-";
33 client_id += String(WiFi.macAddress());
34 Serial.printf("The client %s connects to the public MQTT broker\n", client_id.c_str());
35 if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
36 Serial.println("Public EMQX MQTT broker connected");
37 } else {
38 Serial.print("failed with state ");
39 Serial.print(client.state());
40 delay(2000);
41 }
42 }
43 // Publish and subscribe
44 client.publish(topic, "Hi, I'm ESP32 ^^");
45 client.subscribe(topic);
46 }
47
48 void callback(char *topic, byte *payload, unsigned int length) {
49 Serial.print("Message arrived in topic: ");
50 Serial.println(topic);
51 Serial.print("Message:");
52 for (int i = 0; i < length; i++) {
53 Serial.print((char) payload[i]);
54 }
55 Serial.println();
56 Serial.println("-----------------------");
57 }
58
59 void loop() {
60 client.loop();
61 }
Hi, I'm MQTTX
to the ESP32.
en none 0 Draft
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