Sending Data over HTTP

app.ino

#define SERVER "MYSERVER"
#define SERVERPORT 5000

WiFiClient client;

void sendData(unsigned long timestamp, double speed) 
{   
    // Host and port
    if(client.connect(SERVER, SERVERPORT))
    {
        char body[64];

        // Clear the array to zeroes.
        memset(body, 0, 64);
        
        // Arduino sprintf does not support floats or doubles.
        sprintf(body, "milliseconds=%lu&speed=", timestamp); 
        // Use the dtostrf to append the speed.
        dtostrf(speed, 2, 3, &body[strlen(body)]);

        int bodyLength = strlen(body);

        // Specify the endpoint
        client.println("POST /data/providereading HTTP/1.1");
        
        // Write Host: SERVER:SERVERPORT
        client.print("Host: "); 
        client.print(SERVER);
        client.print(":");
        client.println(SERVERPORT);

        // Close the connection after the request
        client.println("Connection: close");

        // Write the amount of body data
        client.print("Content-Length: ");
        client.println(bodyLength);

        client.println("Content-Type: application/x-www-form-urlencoded");
        client.println();

        client.print(body);

        // Wait for the response
        delay(100);

        // Read the response (but we don't care what is in it)
        while(client.read() != -1);
    }
}