Now, let's start building our first basic IoT edge device. We will use the ESP8266-01 Wi-Fi capable chip. This chip comes loaded with networking layer software and can directly accept AT commands from the Arduino (or any serial terminal) for establishing internet connectivity with ambient Wi-Fi networks:

The ESP8266-01 Wi-Fi transceiver module has eight pins available for connecting with external microcontroller devices. The eight pins are shown in the preceding pinout diagram. There is also an onboard antenna on the right-hand side. This chip can be used as a Wi-Fi connector from the Arduino board. It can also be used as a standalone node MCU (microcontroller unit) by directly loading a sketch into the ESP8266 board, without the Arduino Uno. However, in this chapter, our focus will be on the basic feature of connecting to the internet by using this chip.