Review on 💻 KNACRO 5V 2 Channel 10A PC USB Control Switch Relay Module: Intelligent Driver for Programmable Computer Control by Jose Miller

Not many instructions but you can find out by downloading the program from the link in their description. Works straight away, I bought a single channel and a quad, both work great. Pros: - Easy setup - No additional power supply required for one channel, you need one with 4 or more channels as more power is needed to drive the relay. Cons: - You cannot use additional same blocks. on the same system because the ID is the same. So, for example, if you want to have two channels, you cannot use two individual channels because they have the same ID. You must buy a quad channel - Does not come with a USB cable (forgivable for the price) Notes: - If you are connecting a system that does not recognize a USB HID device, in my case Embedded Windows XP, then you must install a driver for the FTDI chip. You can find the driver here https://ftdichip.com/drivers/d2xx-drivers/. Note that this one doesn't physically use the FTDI chip, but mimics one, possibly using V-USB in firmware.