Reference for Usage Method: 1. The simple for Android APP control board we provide can be used directly without programming. It supports Server and Client modes or external network testing. It is suitable for ordinary people who do not know programming (you can ask the customer service for date). 2. Use the pre-installed firmware program on the board to directly write a PC or mobile control terminal via TCP to control the board. It supports Server and Client modes and is suitable for people who know how to program PC or mobile programs (you can ask the customer service for date). 3. The board is based on ESP8266-12F. You can rewrite the 8266 firmware program to meet your own requirements. The board has a firmware burning interface, which is suitable for those who know how to write 8266 hardware programs. Warm reminder: The board supports 2.4G regular routers but does not support 5G routers. 5G routers cannot be connected! Package Included: 1x Relay Module 1x Shell ‌The secondary development module for remote control based on ESP8266-12F (WiFi module) enables users to program and develop the module independently, design and create their own DIY remote control switch module. There is a program upload interface on the back, allowing for the repeated upload of self-written firmware programs for convenient testing and use. It can be used to create smart switches that can control most household appliances. For example, controlling electric lights, fans, electric blankets, and various other commonly used electrical appliances. Development Method1:;The control program can be developed by oneself through the communication protocol instructions of the device or the server program can be connected for control. The control program can be developed for control by setting the working mode, connection parameters, etc. through the setting tool. The device itself is pre-installed with simple communication methods such as for TCPServer, for TCPClient, for http_GET,for MQTT, and connection to for Bafa Cloud. Development Method2:;If the built-in communication protocol does not meet the usage requirements, the device is based on ESP8266. Those with hardware development capabilities can redevelop the hardware firmware program themselves to fulfill their various needs! The secondary development module for remote control based on ESP8266-12F (WiF i module) enables users to program and develop the module independently, design and create their own DIY remote control switch module. There is a program upload interface on the back, allowing for the repeated upload of self-written firmware programs for convenient testing and use. It can be used to create smart switches that can control most household appliances. For example, controlling electric lights, fans, electric blankets, and various other commonly used electrical appliances.