Skip to content

Instantly share code, notes, and snippets.

@cyrusmeh

cyrusmeh/Connect Arduino Nano to the Internet with W5500 Ethernet Module | Step-by-Step Guide.ino

Created May 16, 2025 19:05
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save cyrusmeh/289d8f5f9a3c3ecb65751c8ed632979b to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save cyrusmeh/289d8f5f9a3c3ecb65751c8ed632979b to your computer and use it in GitHub Desktop.
Download ZIP
In this comprehensive tutorial, we'll show you how to connect your Arduino Nano to the internet or a local network using the W5500 Ethernet Module.
Raw
Connect Arduino Nano to the Internet with W5500 Ethernet Module | Step-by-Step Guide.ino
#include <SPI.h>
#include <Ethernet2.h>
// Network configuration
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 137, 100);
IPAddress gateway(192, 168, 137, 1);
IPAddress subnet(255, 255, 255, 0);
EthernetServer server(80); // HTTP port
// LDR pin
const int LDR_PIN = A0;
int lightValue = 0;
unsigned long lastSensorRead = 0;
void setup() {
Serial.begin(9600);
while (!Serial); // Wait for serial
// Start Ethernet
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
Serial.print("Server is at ");
Serial.println(Ethernet.localIP());
Serial.println("Ready to receive requests and send sensor data...");
}
void loop() {
// Read sensor every 2 seconds
if (millis() - lastSensorRead > 2000) {
lightValue = analogRead(LDR_PIN);
Serial.print("LDR Value: ");
Serial.print(lightValue);
Serial.print(" (");
Serial.print(map(lightValue, 0, 1023, 0, 100));
Serial.println("% brightness)");
lastSensorRead = millis();
}
// Handle client connections
EthernetClient client = server.available();
if (client) {
Serial.println("\nNew client connected");
boolean currentLineIsBlank = true;
String request = "";
while (client.connected()) {
if (client.available()) {
char c = client.read();
request += c;
Serial.write(c);
if (c == '\n' && currentLineIsBlank) {
// Send HTTP response
sendResponse(client);
break;
}
if (c == '\n') {
currentLineIsBlank = true;
} else if (c != '\r') {
currentLineIsBlank = false;
}
}
}
// Log the request
Serial.println("Full request:");
Serial.println(request);
delay(1); // Allow time for browser to receive data
client.stop();
Serial.println("Client disconnected");
}
}
void sendResponse(EthernetClient &client) {
// Read sensor right before sending response for fresh data
lightValue = analogRead(LDR_PIN);
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connection: close");
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
client.println("<head>");
client.println("<title>Arduino LDR Monitor</title>");
client.println("<meta http-equiv=\"refresh\" content=\"5\">"); // Auto-refresh every 5 sec
client.println("<style>");
client.println("body { font-family: Arial, sans-serif; text-align: center; margin-top: 50px; }");
client.println(".sensor-value { font-size: 2em; color: #0066cc; margin: 20px; }");
client.println("</style>");
client.println("</head>");
client.println("<body>");
client.println("<h1>Arduino LDR Monitor</h1>");
client.print("<div class=\"sensor-value\">");
client.print("Light Level: ");
client.print(lightValue);
client.print(" (");
client.print(map(lightValue, 0, 1023, 0, 100));
client.println("%)</div>");
client.println("<p>Page refreshes every 5 seconds</p>");
client.println("<p>Last update: ");
client.print(millis() / 1000);
client.println(" seconds after startup</p>");
client.println("</body>");
client.println("</html>");
Serial.println("Sent sensor data to client");
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment