✍ ESP8266 offers a complete and self-contained Wi-Fi networking solution, allowing it to either host the application or to offload all Wi-Fi networking functions from another application processor.

✍ When ESP8266 hosts the application, and when it is the only application processor in the device, it is able to boot up directly from an external flash. It has integrated cache to improve the performance of the system in such applications, and to minimize the memory requirements.

✍ Alternately, serving as a Wi-Fi adapter, wireless internet access can be added to any microcontroller-based design with simple connectivity through UART interface or the CPU AHB bridge interface.

✍ ESP8266 on-board processing and storage capabilities allow it to be integrated with the sensors and other application specific devices through its GPIOs with minimal development up-front and minimal loading during runtime. With its high degree of on-chip integration, which includes the antenna switch balun, power management converters, it requires minimal external circuitry, and the entire solution, including front-end module, is designed to occupy minimal PCB area.

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▼ Features
Operating voltage: 1.7 to 3.6V (3.3V is standard)
WiFi communication through serial AT commands.
Baud rate: 115200
Integrated low power 32-bit CPU could be used as application processor
On board build it antenna.
802.11 b/g/n protocol
Wi-Fi Direct (P2P), soft-AP
Integrated TCP/IP protocol stack
Integrated TR switch, balun, LNA, power amplifier and matching network
Integrated PLL, regulators, and power management units
+19.5dBm output power in 802.11b mode
Integrated temperature sensor
Supports antenna diversity
Power down leakage current of < 10uA
Integrated low power 32-bit CPU could be used as application processor
SDIO 2.0, SPI, UART
STBC, 1×1 MIMO, 2×1 MIMO
A-MPDU & A-MSDU aggregation & 0.4s guard interval
Wake up and transmit packets in < 2ms
Standby power consumption of < 1.0mW (DTIM3)
Applications
Smart power plugs
Home automation
Mesh network
Industrial wireless control
Baby monitors
IP Cameras
Sensor networks
Wearable electronics
Wi-Fi location-aware devices
Security ID tags
Wi-Fi position system beacons