Arduino UNO ESP8266 Serial WiFi Expansion Board Module Documentation
The Arduino UNO ESP8266 Serial WiFi Expansion Board Module is a breakout board that combines the popular Arduino UNO with the ESP8266 WiFi module, enabling users to add WiFi capabilities to their Arduino projects. This module provides a simple and cost-effective way to connect to the internet and communicate with other devices wirelessly.
Onboard ESP8266 WiFi module
Serial communication interface for easy integration with Arduino boards
Supports 802.11 b/g/n WiFi protocols
Up to 72 Mbps data transfer rate
Compatible with Arduino UNO and other Arduino boards
Power supply: 3.3V or 5V
The module has the following pinout:
RX: Receive pin (connected to Arduino's TX pin)
TX: Transmit pin (connected to Arduino's RX pin)
VCC: Power supply pin (3.3V or 5V)
GND: Ground pin
EN: Enable pin (active low)
RST: Reset pin (active low)
The module uses the Arduino ESP8266WiFi library, which provides a simple and intuitive API for communicating with the ESP8266 module.
Example 1: Connecting to WiFi and Sending Data to a Server
This example demonstrates how to connect to a WiFi network and send data to a server using the ESP8266 module.
```c
#include <ESP8266WiFi.h>
// WiFi credentials
const char ssid = "your_wifi_ssid";
const char password = "your_wifi_password";
// Server details
const char server = "example.com";
const int port = 80;
void setup() {
Serial.begin(115200);
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
Serial.println("Initializing ESP8266 module...");
// Initialize ESP8266 module
ESP8266.begin();
delay(1000);
// Connect to server
if (!client.connect(server, port)) {
Serial.println("Connection failed");
return;
}
Serial.println("Connected to server");
}
void loop() {
// Send data to server
client.println("Hello, world!");
client.println("This is a test message from Arduino");
delay(1000);
}
```
Example 2: Creating a Simple WiFi Web Server
This example demonstrates how to create a simple WiFi web server using the ESP8266 module, which can be accessed from a web browser.
```c
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
// WiFi credentials
const char ssid = "your_wifi_ssid";
const char password = "your_wifi_password";
// Create a web server on port 80
ESP8266WebServer server(80);
void setup() {
Serial.begin(115200);
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
Serial.println("Initializing ESP8266 module...");
// Initialize ESP8266 module
ESP8266.begin();
delay(1000);
// Set up web server
server.on("/", handleRoot);
server.begin();
}
void loop() {
server.handleClient();
}
void handleRoot() {
server.send(200, "text/html", "<h1>Hello, world!</h1><p>This is a test web server from Arduino.</p>");
}
```
Example 3: Sending and Receiving Data using MQTT Protocol
This example demonstrates how to use the ESP8266 module to send and receive data using the MQTT protocol.
```c
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
// WiFi credentials
const char ssid = "your_wifi_ssid";
const char password = "your_wifi_password";
// MQTT broker details
const char mqttServer = "your_mqtt_broker_ip";
const int mqttPort = 1883;
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
Serial.begin(115200);
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
Serial.println("Initializing ESP8266 module...");
// Initialize ESP8266 module
ESP8266.begin();
delay(1000);
// Connect to MQTT broker
client.setServer(mqttServer, mqttPort);
client.setCallback(mqttCallback);
client.connect();
}
void loop() {
// Publish a message to an MQTT topic
client.publish("your_topic", "Hello, world!");
// Subscribe to an MQTT topic
client.subscribe("your_topic");
delay(1000);
}
void mqttCallback(char topic, byte payload, unsigned int length) {
Serial.print("Received message on topic ");
Serial.print(topic);
Serial.print(": ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
}
```
Note: These examples assume that you have the necessary WiFi credentials, server details, and MQTT broker information. You will need to modify the code to fit your specific use case.
