Characteristics
1. wifi with industrial chip esp8266, module esp-13 with metal shield cover, strong anti-jamming capability
-standard pins compatible with uno, mega2560, etc. main control board, uno connection using voltage conversion chip, making 3.3v and 5v compatible
-double-circuit dial switches are used to control serial ports so that the expansion board can be used either separately as uno extension board or as esp8266 extension board
-real serial port wifi, no configuration required
-configure wifi parameters and serial port parameters based on web server
-can be used as an independent esp8266 development board, download official at instruction firmware, nodemcu open source firmware, etc.
-can be used as an independent uno extension board, with all the pins drawn.

Technical specifications
-support wireless 802.11 b/g/n standards
-support sta/ap two working models
-built-in tcp/ip protocol stack with a socket
-support standard tcp/udp server and client
-serial port port rate support: 1200/2400/4800/9600/19200/38400/57600/74800/115200 bps
-serial port data bits: 5/6/7/8
-serial parity test: none
-serial stop: 1/2 bits
-standard uno, mega lead spacing
-lead to arduino pin 2/3/4/5/6/7/8/9/10/11/12/13
-esp8266 gpio 0/2/4/5/9/10/12/13/14/15/16/adc/en/uart tx/uartrx
12. reset
13, key button reuse configuration function
-implementation of esp8266 serial port extension switch
15. wifi working current: continuous transmission: 70ma (200ma max), standby: 200ua
-wireless transmission rate: 110-460800bps
-working temperature:-40°C~+ 125°C
-module weight: approximately 20g

Shipping list:

Esp8266 expansion board: 1pcs