Description :

The SparkFun ESP8266 Thing is a breakout and development board for the ESP8266 WiFi SoC, which is a leading platform for Internet of Things (IoT) or WiFi-related projects
The board is low-cost and easy to use, and can be integrated with the Arduino IDE in just a few steps
The Thing has all of the module's pins broken out, a LiPo charger, power supply, and all other supporting circuitry it requires
The name "Thing" is due to it being the perfect foundation for your Internet of Things project
The Thing can be programmed like any microcontroller and can do everything from turning on an LED to posting data with datastream
The board has two parallel, breadboard-compatible rows of pins, USB and LiPo connectors for power, and LEDs for power, charge, and status indication
The ESP8266's maximum voltage is 3.6V, so the Thing has an onboard 3.3V regulator to provide a safe, consistent voltage to the IC
The ESP8266's I/O pins run at 3.3V, so level shifting is required for any 5V signals running into the IC
A 3.3V FTDI Basic is required to program the SparkFun ESP8266 Thing, other serial converters with 3.3V I/O levels can also work
The converter needs a DTR line in addition to the RX and TX pins

Features:

 All module pins broken out
On-board LiPo charger/power supply
802.11 b/g/n
Wi-Fi Direct (P2P), soft-AP
Integrated TCP/IP protocol stack
Integrated TR switch, balun, LNA, power amplifier and matching network
Integrated PLLs, regulators, DCXO and power management units
Integrated low power 32-bit CPU could be used as application processor
19.5dBm output power in 802.11b mode