ESP8266-03 WiFi Module (ESP-03)

The ESP8266 is a highly integrated chip designed for the needs of a new connected world. It offers a complete and self-contained Wi-Fi networking solution, enabling it to either host the application or offload all Wi-Fi networking functions from another application processor. With powerful on-board processing and storage capabilities, the ESP8266 can integrate with sensors and other application-specific devices through its GPIOs with minimal development effort and runtime loading. Its high degree of on-chip integration allows for minimal external circuitry, occupying minimal PCB area.

Features:

SDIO 2.0, SPI, UART interfaces
32-pin QFN package
Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
Integrated RISC processor, on-chip memory, and external memory interfaces
Integrated baseband processors
Quality of Service management
I2S interface for high-fidelity audio applications
On-chip low-dropout linear regulators for all internal supplies
Proprietary spurious-free clock generation architecture
Integrated WEP, TKIP, AES, and WAPI engines
Supports APSD for optimal VoIP applications
Patented spurious noise cancellation algorithm
Supports Bluetooth coexistence interface
Self-calibrated RF for optimal performance
No external RF components required

Specifications:

802.11 b/g/n support
Wi-Fi Direct (P2P), soft-AP mode
Integrated TCP/IP protocol stack
Integrated TR switch, balun, LNA, power amplifier, and matching network
Integrated PLLs, regulators, DCXO, and power management units
+19.5dBm output power in 802.11b mode
Power down leakage current < 10uA
Integrated low-power 32-bit CPU
SDIO 1.1/2.0, SPI, UART interfaces
STBC, 1x1 MIMO, 2x1 MIMO support
A-MPDU & A-MSDU aggregation & 0.4ms guard interval
Wake up and transmit packets in < 2ms
Standby power consumption < 1.0mW (DTIM3)

Additional Information:

High quality & low price
LWIP protocol support
Supports 3 modes: AP, STA, AP+STA
Simple AT commands for configuration

Perfect for your next Internet of Things project, home automation, or remote sensor application. This module adapts the ESP8266 IC for use over a serial connection using simple AT commands, eliminating the need for SPI interface or in-depth technical know-how.

Warning:

This module requires a 3.3V supply for VCC and 3.3V logic levels. It is not 5V tolerant. Connecting RX or TX to 5V will damage the module.
You must use a logic level converter or a 3.3V Arduino board.
The 3.3V supply on the Arduino Uno may not provide sufficient current. Use a separate 3.3V power supply (about 300mA or better).
Support and documentation for this module may be limited as it is relatively new on the market.