ESP8266 WiFi modules

The ESP8266 Wi-Fi modules are tiny low-cost boards comprising a Wi-Fi radio transceiver, a 32 bit micro-controller and flash memory. They are programmable and can be connected to computing devices (Arduino and others) or used as standalone devices.

At the heart of the modules is the ESP8266EX chip which integrates an enhanced version of Tensilica’s L106 Diamond series 32-bit RISC processor. The MCU runs between 80-160Mhz, has low power consumption and two power saving modes. It is a complete and self-contained WiFi networking solution, can work as an Wi-Fi adapter or integrated with external sensors and other application specific devices through its GPIO's.

The ESP8266 is available in several configurations, with more or less memory, more or less I/O (GPIO) ports, different antennas, with or without shielding and with or without connection header. Most of these modules are named ESP-01 to ESP-14. The smallest is just 10x10mm!

Target applications for the ESP8266 are mobile devices, wearable electronics and the Internet-of-Things (IoT): home appliances, home automation, smart plug and lights, IP cameras, baby monitors, sensor networks, etc.

Recently (April 2016) AI-Thinker has released the ESP 32 series, ESP 85 series (ESP8285) and ESP-S series of WIFI modules.

MAIN FEATURES:
WiFi 2.4Ghz;
802.11 b/g/n protocol;
Wi-Fi modes: station/softAP/SoftAP+station;
Support STA/AP/STA+AP operation modes;
Integrated TCP/IP protocol stack;
Security: WPA/WPA2;
Encryption: WEP/TKIP/AES;
Low power consumption 32-bit MCU;
10-bit ADC;
UART serial connection;
Power supply: 3.3 Volts

The ESP8266 is designed by Espressif Systems, a fabless semiconductor company from Shangai, China. Initially modules where made by AI-Thinker but now they are available from other vendors also. They can be bought from dealextreme, banggood, ebay and may other places.

Documentation and tools:
Download ESP8266 datasheet here.
Further ESP8266 information, documentation and tools available on the Espressif Systems site. 
List of ESP8266 modules and specifications of  ESP8266 modules from AI-Thinker (not full list) can be downloaded here.

NEXT: ESP8266 ESP-01 testing - Part 1