The day before Makers around the world celebrated Arduino day on March 28, 2015, major news quietly hit the ESP8266 forums. A post by Richard Sloan declared that he and Ivan Grokhotkov had successfully hacked ESP8266 support into the Arduino IDE. For those following the forum this announcement was a big deal; for everyone else, it would be a week or two before Sloan and Grokhotkov’s work resonated: The ESP8266, until then used only as a Wi-Fi accessory for Arduinos and other microcontrollers, could be programmed directly as a standalone board.
Available for $3-$7 (even less in quantity), the ESP8266 was originally designed as a Wi-Fi communication expansion board. Prior to Sloan and Grokhotkov’s software, users had already noted that it could be programmed using basic modem instructions known as AT-commands. Microcontrollers easily parse AT commands, but they are not fun for humans to work with. Developing an interface with more user-friendly programming language, such as the C/C++ familiar to Arduino sketch programmers, is what made the ESP8266 vastly more popular.
The Espressif Systems ESP8266-01 lacks an FTDI chip, which typically allows a board to have an external communication port like USB, so you have to use a separate hardware interface such as the FTDI Friend to program it. Fortunately, instructions are now easily available to set everything up properly.
Thanks to these software improvements, it’s easier than ever for people to create projects with the ESP8266 at the center of their design. Internet of Things projects, such as data logging stations or panic buttons, are the most common. With each project, small Arduino sketches run directly on the ESP8266 and shuttle data between the input pins and the Wi-Fi connection.
Espressif Systems, the company that manufactures the ESP8266, has been so receptive to feedback about their product and how it is being used that their next board, the ESP32, is integrating much of the community’s suggestions into the design. Now entering a beta phase, the new board is planned to have faster Wi-Fi, onboard Bluetooth, and two processors to handle the Wi-Fi and code execution separately.
Whether it’s adding Wi-Fi to a board that lacks it (such as the Pi Zero), or simply running the ESP8266 in a standalone mode, the board is certainly worth experimenting with, and cheap enough to buy a bunch.