The Internet of Things with ESP8266

What is the "Internet of things"?

The Internet of things (IoT) is the network of everyday objects — physical things embedded with electronics, software, sensors, and connectivity enabling data exchange. Basically, a little networked computer is attached to a thing, allowing information exchange to and from that thing. Be it lightbulbs, toasters, refrigerators, flower pots, watches, fans, planes, trains, automobiles, or anything else around you, a little networked computer can be combined with it to accept input (especially object control) or to gather and generate informational output (typically object status or other sensory data). This means computers will be permeating everything around us — ubiquitous embedded computing devices, uniquely identifiable, interconnected across the Internet. Because of low-cost, networkable micro-controller modules, the Internet of things is really starting to take off.

What is ESP8266?

The Chip

ESP8266 (presently ESP8266EX) is a chip with which manufacturers are making wirelessly networkable modules. More specifically, ESP8266 is a system-on-chip (SoC) with capabilities for 2.4 GHz Wi-Fi (802.11 b/g/n, supporting WPA/WPA2), general-purpose input/output (16 GPIO), Inter-Integrated Circuit (I²C), analog-to-digital conversion (10-bit ADC), Serial Peripheral Interface (SPI), I²S interfaces with DMA (sharing pins with GPIO), UART (on dedicated pins, plus a transmit-only UART can be enabled on GPIO2), and pulse-width modulation (PWM). The processor core, called "L106" by Espressif, is based on Tensilica's Diamond Standard 106Micro 32-bit processor controller core and runs at 80 MHz (or overclocked to 160 MHz). It has a 64 KB boot ROM, 64 KB instruction RAM and 96 KB data RAM. External flash memory can be accessed through SPI.

The Modules

Vendors have consequently created a multitude of compact printed circuit board modules based around the ESP8266 chip. Some of these modules have specific identifiers, including monikers such as "ESP-WROOM-02" and and "ESP-01" through "ESP-14"; while other modules might be ill-labeled and merely referred to by a general description — e.g., "ESP8266 Wireless Transceiver." ESP8266-based modules have demonstrated themselves as a capable, low-cost, networkable foundation for facilitating end-point IoT developments. Espressif's official modules are presently ESP-WROOM-02 and ESP-WROOM-S2. The Ai-Thinker modules are succinctly labeled ESP-01 through ESP-14. (Note: many people refer to the Ai-Thinker modules with the unofficial monikers of "ESP8266-01" through "ESP8266-14" for clarity.) See the ESP8266 article on Wikipedia for more information about popular ESP8266 modules.

The Development Boards/Modules

ESP8266 based development boards/modules often incorporate a surface-mount PCB module, a on-board USB-to-serial bridge, and breakout to 0.1 inch pitch connections. For example, the NodeMCU Development Kits use Ai-Thinker modules, and the Adafruit Feather HUZZAH uses an Ai-Thinker ESP-12S module and a SiLabs CP2104 USB-to-serial bridge chip.

Where can I get it?

Disclaimer: Vendors are listed for informational purposes only. Buyers should use prudence and careful judgement when ordering. Before ordering, read all product descriptions and check vendor ratings when possible. Prices listed below are approximate and do not include shipping costs. Furthermore, prices listed below may be outdated, so be diligent and check for yourself.

Where can I learn more about it?

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