Write POST Data to Server with Arduino Uno with WiFi

This project shows you how to send data to a server with POST from an Arduino Uno with WiFi and to have the server parse the data using a PHP script.

Functional Parts in the Project:

• Arduino WiFi Rev 2 – https://store.arduino.cc/usa/arduino-uno-wifi-rev2
• Breadboard Kit – https://amzn.to/2Xih5ei
• 560 Piece Jumper Wire Kit – https://amzn.to/2MsCLjL
• Analog Temperature Sensor – https://amzn.to/2Rkkl3k

#include <WiFiNINA.h>

#define sensorPin A5

char ssid[] = "test";
char pass[] = "";

int status = WL_IDLE_STATUS;

char server[] = "www.elithecomputerguy.com";

String postData;
String postVariable = "temp=";

WiFiClient client;

void setup() {

  Serial.begin(9600);

  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");
    Serial.println(ssid);
    status = WiFi.begin(ssid, pass);
    delay(10000);
  }

  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());
  IPAddress ip = WiFi.localIP();
  IPAddress gateway = WiFi.gatewayIP();
  Serial.print("IP Address: ");
  Serial.println(ip);
}

void loop() {
  int reading = analogRead(sensorPin);
  float voltage = reading * 5.0;
  voltage /= 1024.0;
  float temperatureC = (voltage - 0.5) * 100 ;
  float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;

  postData = postVariable + temperatureF;

  if (client.connect(server, 80)) {
    client.println("POST /test/post.php HTTP/1.1");
    client.println("Host: www.elithecomputerguy.com");
    client.println("Content-Type: application/x-www-form-urlencoded");
    client.print("Content-Length: ");
    client.println(postData.length());
    client.println();
    client.print(postData);
  }

  if (client.connected()) {
    client.stop();
  }
  Serial.println(postData);

  delay(3000);
}

PHP Script – post.php

<?php
$time = time();
$tempF = $_POST["temp"];
$file = 'temp.html';
$data = $time."  -  ".$tempF;
file_put_contents($file, $data);
?>