MakerFocus 4 Channel Relay Board Module for Raspberry Pi 4B/3 Model B+/Raspberry Pi 3/2 Model B

Product Decription:4 Channel Relay Hat Board For Raspberry Pi is one of the "docker pi" module.It has a 4-channel relay, it is the best choice for smart home projects.This four-channel relay uses high-quality relay modules combined with the most popular microcontroller technology to communicate with the Raspberry Pi.You can use multiple modules stacked together for use. You can stack up to four layers.Switch the I2C address of the device through the DIP switch on the circuit board to ensure that the four-layer module gets different addresses, thus avoiding the problem of address duplication.The module is very fast, easy to install, and supports multi-language development, making it ideal for smart home projects.NOTE: The 4pin pin is a backup that supplies power to future products. You can ignore those pins. Please do not connect any device to that pins.   Product Features:Easy to install4 channel relaySupport I2C protocolSupport for stackingSupport multi-language programmingSupport 3A 250V ACSupport 3A 30V DCSupport address switching by dial switchSupport relay status light prompt Product Advantage:Independent of the programming language, it only need I2C protocol supportYou could use the command control directily instead of programmingUse the raspberry pi to replace the trandition switch Compatiable with multiple protection board   Packing List: 1 * 4-Channel Relay Hat Board4 * M2.5x11+6 copper stick8 * M2.5x5 screws & nuts1 * Instructions