Product parameters:
* Product size: 45 * 28mm
* Operating voltage: DC5V
* Communication: WIFI (ESP8266 module)
* Serial communication parameters: 9600,8,1,0,0
* Transmission distance: the maximum transmission distance of 400m (open environment, mobile phone equipped with WIFI module)
* Load: 10A/250VAC 10A/30VDC, the relay pull 100,000 times

Way of working:
* Mobile phone equipped with WiFi module;
* Mobile phone and WiFI module equipped with the same router, through the mobile phone APP to control the relay; this mode, the
transmission distance depends on the signal router.

Tips:
* ESP8266 module has a timeout mechanism, when the phone for some time (the default 180S) did not give instructions to the
module, the module will kick off the phone, the computer can send AT + CIPSTO = to modify this time (Time range 0-7200),
such as: AT + CIPSTO = 3600.
* When the module on the WIFI module is unplugged, USB to TTL module RX, TX, GND pins were connected to the module RX, TX, GND
pin, IN +, IN- 5V power supply, then the module can be used as a USB Relays to use, scalability.

NB: ESP8266 ESP-01 not included