Arduino HTTP Request

This worked on April 11, 2025 for an Arduino R4 using the Arduino Desktop IDE on a Windows 11 computer. 

Make Sure that the Arduino IDE is updated to the most recent version. 

Update the Arduino R4 board package: 

• Go to Tools>Board>Board Manager → Search for "Arduino UNO R4" → Install/update to the latest version

Note that this 

#include <WiFiS3.h> // Correct library for UNO R4 WiFi

const char ssid[] = "My_ssid";
const char password[] = "My_password";

void setup() {
  Serial.begin(9600);
  while (!Serial);

  // Connect to WiFi
  if (WiFi.begin(ssid, password) != WL_CONNECTED) {
    Serial.println("WiFi connection failed!");
    while (true);
  }
  Serial.println("Connected to WiFi!");
  
  // Send HTTP GET request
  WiFiClient client;
  if (client.connect("jsonplaceholder.typicode.com", 80)) {
    client.println("GET /comments?id=10 HTTP/1.1");
    client.println("Host: jsonplaceholder.typicode.com");
    client.println("Connection: close");
    client.println();
  }

  // Read response
  while (client.connected()) {
    String line = client.readStringUntil('\n');
    Serial.println(line);
  }
}

void loop() {}