xWifi 是一个开源的 Wifi 硬件模块，硬件规格：
SoC – Mediatek MT7681 802.11 b/g/n SoC with 32-bit RISC CPU. Support for Client/softAP mode. Package size 5×5 mm
Storage – 512KB SPI Flash (for firmware)
I/Os via headers:
UART and SPI interfaces.
5x GPIOs
PWM
Power – 3.3V, GND
Power Consumption – ~70mA @ 5V (during RX active)
Dimensions – 14 x 17 mm
