Uhubctl – Control USB power per-port on smart USB hubs
github.com35 points by gregsadetsky 4 hours ago
35 points by gregsadetsky 4 hours ago
Is there any way to make it so that when you plug new things in, the power doesn't renegotiate causing other things plugged in to reconnect/flicker/interrupt.
Looking for high power USB C hubs that don't do that, but seems most do as part of PD and need isolated slots that don't draw from shared potential... programmatically locking specific power to laptop hub, while others negotiate would be ideal...
Jeff Geerling has some videos about that. It's a hardware thing. https://www.youtube.com/watch?v=twoAW0eLiXY
Super useful, just wish it was easier to find supported devices. I ended up ordering 3 from Amazon that looked like they should work from the list, but ended up not completely cutting power, or having other issues. I think especially the cheap hubs will changes the parts used overtime and not update the revision.
Using on a CI pipeline to dfu flash and devices and run some tests. If anyone has some know to work that I order today let me know!
I created these which I guarantee to work https://modularkvmip.com/product/usb-hub
These look great. I wish they had existed way back when I did embedded work every day. What was the process like to create them? Did you design them from scratch, get them built to spec, something in between?
The switchable host is interesting to me. What do people use that for?
I had a similar usecase and also struggled with supported devices. Ended up grabbing some Yepkit switchable hubs (aka YKUSH), they work great, but a tad on the pricey side.
These are what I use: https://www.amazon.com/dp/B096YKDYX5
However, to your point:
> I think especially the cheap hubs will changes the parts used overtime and not update the revision.
Yeah, the last time I purchased them was December 2022, so I definitely don't know for sure that they still work. But they aren't the cheapest hub, so maybe?
But at that time, I purchased hubs from several manufacturers, and most of them didn't work. The first thing I had working was actually an eval kit from an IC vendor.
Also, many hubs that can theoretically be used powered or unpowered are terrible about backfeeding power, either to the host, or (more commonly) to the wall wart.
It's best to either always use the hub unpowered, or to buy a hub that always requires power, unless you've checked and made sure that it's not going to screw you over.
My display has USB hub with several USB ports in it.
I've taped a LED strip on the back of the display and powered it from one of the USB ports.
By running `uhubctl --vendor 0451 --action toggle --port 4` from the desktop shortcut, I can toggle LED strip on and off, Philips Ambilight-style.
Turning things on and off with a computer is always fun to me (think X10 modules, blinking LEDs with an Arduino, etc). That in itself makes this neat to me.
There's probably a way this could be used to floating batteries at around 80% on devices that support throttling their own charging.
I use this to toggle power to a 3d printer. It gets it actual power from a switched socket but usb still powers the board.
I did a similar thing with a rack of test equipment. I had a PC power supply on each shelf, and used an NPN transistor to turn on the power supply whenever the USB port connected from the main computer to that shelf rack was turned on. Crude, but effective, out of band communication.
The local USB hub on the shelf was powered from the PC power supply on that shelf, so a single long USB cable from the shelf with the control computer could command the shelf (including the USB hub on the shelf) to fully power up or down, and then control several test devices through the USB hub, and none of the USB devices on the shelf (some of which were bus-powered) needed to worry about not getting sufficient voltage through a long cable and a hub.
nice. I was actually looking for something to control the power on the computer's ports. I have a lidar connected to Orin(running Ubuntu) and the lidar constantly turns. Being able to control power to that would be nice. I think powertop would work, haven't tried it yet.