Command-line tools and Node-RED on a Raspberry Pi let you control projects that use the USB ports.
For home automation projects, a Raspberry Pi offers a simple, low-cost approach to managing and controlling a wide variety of devices. Typically these devices are either digitally wired 0-5V devices such as motion detectors, or wireless Ethernet devices such as smart plugs. It’s important to note that a Raspberry Pi can also control USB-powered devices, such as USB fans, lights, and low-end controllers.
In this article, I look at how to monitor, control, and measure USB power in two Raspberry Pi projects. The first project uses Node-RED to create a web dashboard to monitor and control USB lights. The second project turns on USB cooling fans according to the Pi’s CPU temperature.
Controlling USB Ports
A number of techniques allow you to control USB ports, and I found that one of easiest approaches is to use the
uhubctl  utility, which lets you view and control local USB ports and ports on smart USB hubs. To load this utility, enter:
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