Making HTTP GET Requests with ESP32 Using Arduino

The ESP32 microcontroller is a powerful and versatile device for IoT applications. Combining it with the Arduino framework enables you to leverage its capabilities to interact with web services via HTTP requests. In this guide, we'll walk through the steps to perform an HTTP GET request using an ESP32 board.

Prerequisites

Before getting started, ensure you have the following:

1. ESP32 Board: Such as the ESP32 Dev Module or any compatible board.

2. Arduino IDE: Download and install the latest version.

3. WiFi Connection: Access to a Wi-Fi network.

Setting Up the Arduino IDE

1. Install ESP32 Board: Go to File > Preferences in Arduino IDE, paste the following URL in the "Additional Boards Manager URLs" field: https://dl.espressif.com/dl/package_esp32_index.json

2. Install ESP32 Board Package: Navigate to Tools > Board > Boards Manager, search for "esp32" and install the package.

Writing the Code

#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "YourNetworkSSID";
const char* password = "YourNetworkPassword";

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println("Connected to WiFi!");
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    
    // Your target URL for the GET request
    http.begin("https://your-api-endpoint.com/data");
    
    int httpCode = http.GET();
    
    if (httpCode > 0) {
      String payload = http.getString();
      Serial.println(httpCode);
      Serial.println(payload);
    } else {
      Serial.println("Error on HTTP request");
    }
    
    http.end();
    
    delay(5000); // Wait for 5 seconds before the next request
  }
}

How the Code Works

• WiFi Connection: The code initializes the Wi-Fi connection using your network SSID and password.

• HTTPClient Library: It includes the necessary libraries for handling HTTP requests.

• GET Request: The http.GET() method sends an HTTP GET request to the specified URL.

• Handling Response: It checks the HTTP response code and retrieves the response payload if the request was successful.

Uploading and Testing

1. Upload Code: Connect your ESP32 board to your computer, select the appropriate board and port in Arduino IDE, then upload the code.

2. Monitor Serial Output: Open the Serial Monitor (Tools > Serial Monitor) to view the output. You should see the HTTP response code and the fetched data from the API.

Conclusion

With this guide, you've learned how to make an HTTP GET request using an ESP32 board and Arduino. This capability opens up a world of possibilities for IoT projects, allowing you to interact with online services and fetch data for your applications.

Experiment with different APIs and endpoints to integrate your ESP32 projects with web services seamlessly!