30MinuteWiFiCheck.ino

#include <ESP8266WiFi.h>

// WiFi settings
const char* ssid = "SSID_NAME";
const char* password = "SSID_PASSPHRASE";

// Device Settings
// I use the last 6 characters of the WiFi MAC address as device ID
const char* device_id = "123456"; 

// API Settings
const char* host = "my.domain.com";
const uint16_t port = 80;

WiFiClient client;

void setup_wifi() {
  delay(10);

  // Announce connection
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  // Setup WiFi config and connect
  WiFi.mode(WIFI_STA);
  //WiFi.config(ip, gateway, subnet);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected, IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're connected
  while (!client.connected()) {
    Serial.print("Attempting connection...");

    // Attempt to connect
    if (client.connect(host,port)) {
      // Success
      Serial.println("connected");
    } else {
      // Fail
      Serial.print("failed");
      Serial.println(" try again in 5 seconds");

      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);

  // Start WiFi setup
  setup_wifi();

}

void loop() {
  if (!client.connected()) {
    reconnect();
  } else {

    Serial.println("Making Request to Server");
    client.println((String)"GET /?device_id=" + device_id + " HTTP/1.0");
    client.println((String)"Host: " + host);
    client.println("Connection: keep-alive");
    client.println("Cache-Control: max-age=0");
    client.println("User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko)");
    client.println("Accept-Encoding: gzip, deflate");
    client.println("Accept-Language: en-US,en;q=0.9"); 
    client.println(); 
    delay(1000);

    // Sleep 30 minutes (deepSleep is defined in microseconds)
    Serial.print("Going to sleep...");
    ESP.deepSleep(30 * 60 * 1000000);

    delay(3000);
  }
}