In this video, I show how to connect an ESP8266 to the Arduino Mega 2560, and I send data to my phone which is running the Blynk app. I can also control an LED from the Blynk app. This tutorial assumes that you already know how to create simple Arduino projects. Aside from that, no special skills are needed. Yes, you really DO need an external supply to make this circuit work. Or you need an adapter like the one I use in the video. The supply from the Arduino Mega does not provide enough current to run the ESP module. If you want to know how to connect an Arduino Uno to an ESP-01, watch my "sequel" video: This is a pretty long video, so I have included a "table of contents" below: 0:00 Introduction 1:54 Project Hardware 8:38 Download AT Command firmware for the ESP8266 12:53 Download the app to flash the firmware to the ESP8266 16:42 Wiring up the circuit to flash the ESP8266 19:17 Flashing the AT Command firmware to the ESP8266 24:01 Wiring up the Arduino Mega 2560 + ESP8266 27:05 Setting up the Blynk app to send and received data 33:17 Write Arduino code for the LED and millis 38:46 Confirm Wifi is working and connected to the Blynk cloud server 39:19 Confirm the LED button works and Millis is displayed 39:49 Add code to run the temperature sensor and push data to the Blynk app 43:18 Confirm the temperature data is being sent to the phone 44:16 Conclusion - Bye! There are several websites that I use in the video. The links are below: This is the first link I show in the video. It takes you to the documentation page of the Blynk website. #hardware-set-ups-arduino-esp8266-wifi-with-at-commands This is the link to get the AT_Command firmware This is the link to get the flasher app that I used in the video: This page shows an example sketch for the DS18b20 sensor: The Arduino sketch ( ) shown near the end of the video can be found here: ******************** This project requires certain libraries to be loaded into your Arduino IDE. To get the ESP8266 and Blynk libraries, go to this site: … click on "Download Blynk Library", and follow the instructions The temperature sensor used in this video requires two libraries that can be downloaded from SunFounder. The zip folder can be found here: ==/dispa Open the zip folder and navigate to find… \ \Sensor Kit V2.0 for Arduino\Library\Ds18b20 … and… \ \Sensor Kit V2.0 for Arduino\Library\OneWire Copy those two library folders into your Arduino library folder. **********************