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Ever wondered how fast your WiFi network really is? While internet service providers promise high speeds, real-world performance can fluctuate due to network congestion, signal interference, or hardware limitations.
In this tutorial, we’ll build an ESP32-based WiFi Network Speed Monitor that runs periodic tests and displays results in requests per second (req/s) or megabits per second (Mbps). This IoT-powered speed test will help monitor network stability and detect downtime.
What You’ll Learn:
Connecting an ESP32 to WiFi
Sending HTTP requests and measuring response time
Calculating network speed in Mbps
Displaying speed metrics via Serial Monitor or OLED
Implementing an automatic network health check
Required Components
Before starting, ensure you have the following:
ESP32 Development Board
WiFi Connection (2.4GHz recommended for ESP32)
Arduino IDE (with ESP32 Board installed)
Jumper Wires (if using a display)
OLED Display (Optional)
How the ESP32 Network Speed Test Works
WiFi Connection: ESP32 connects to your WiFi network.
HTTP Requests: It sends multiple requests to a test server (httpbin.org).
Response Time Measurement: Calculates request duration to estimate network speed.
Data Processing: Converts speed into requests per second or megabits per second (Mbps). Display Results: Outputs results via Serial Monitor or an OLED screen.
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Setting Up Arduino IDE
Before writing code, install the following libraries:
WiFi.h - ESP32 WiFi connectivity
WiFiClientSecure.h - Secure HTTPS requests
ArduinoJson.h - (Optional) For handling API data
To install:
Open Arduino IDE → Go to Sketch → Include Library → Manage Libraries
Search for WiFiClientSecure, ArduinoJson, and install them.
ESP32 Network Speed Test Code
Here’s the complete ESP32 code to measure WiFi speed in requests per second and Mbps
#include <WiFi.h>
#include <WiFiClientSecure.h>
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";
const char* testHost = "httpbin.org"; // Test server for HTTP requests
const int testPort = 80;
WiFiClient client;
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
Serial.print("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print(".");
}
Serial.println("\nConnected to WiFi!");
}
void loop() {
Serial.println("Testing network speed...");
int numRequests = 10; // Number of HTTP requests
long startTime = millis();
for (int i = 0; i < numRequests; i++) {
if (client.connect(testHost, testPort)) {
client.print(String("GET /get HTTP/1.1\r\n") +
"Host: " + testHost + "\r\n" +
"Connection: close\r\n\r\n");
while (!client.available()) {
delay(10);
}
while (client.available()) {
client.read();
}
client.stop();
} else {
Serial.println("Connection failed!");
}
}
long elapsedTime = millis() - startTime;
float speedReqSec = (float)numRequests / (elapsedTime / 1000.0);
float speedMbps = (numRequests * 0.2 * 8) / (elapsedTime / 1000.0); // Approx. 200 bytes per request
Serial.print("Network speed: ");
Serial.print(speedReqSec);
Serial.println(" requests per second");
Serial.print("Download speed: ");
Serial.print(speedMbps);
Serial.println(" Mbps");
delay(60000); // Run test every 1 minute
}
Code Explanation
Connects ESP32 to WiFi Sends
10 HTTP requests to httpbin.org
Measures total time taken for all requests
Calculates speed:
Requests per second (req/s)
Download speed (Mbps) using DataSize * 8 / TimeTaken formula
Repeats speed test every 60 seconds
Displaying Data on an OLED Screen (Optional)
If you’d like visual feedback, connect an SSD1306 OLED display and modify the code:
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
void setup() {
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
}
void loop() {
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 10);
display.println("Speed: " + String(speedMbps) + " Mbps");
display. Display();
}Enhancements & Future Improvements
You can extend this project by: ✅ Adding a Web Dashboard – ESP32 hosts a web page displaying results. ✅ Storing Data – Log speed trends using Firebase or an SD card. ✅ Real-time Alerts – Trigger a notification when the WiFi speed drops below a threshold.
Conclusion
With this ESP32-powered network speed monitor, you can check WiFi performance, detect fluctuations, and even automate connectivity testing for smart home applications. 🚀
