Ha! Funny timing I literally just bought a cheap 7 port usb hub off ebay and then wired it to be powered externally by a powerbank (I use a 10000 mah 2.4 amp anker that works more than sufficiently for my purposes, and assuming your midi devices arent drawing crazy amounts of power that should be good for you too) I got the idea from external harddrives that have y splitter cables If you desolder the 5v pin from the usb cable on the usb hub, it will no longer be powered by your computers usb port, but can still communicate with it (keep the gnd connected!). Then you can either solder on a port or a wire(I used a wire since i dont have many micro USB ports on hand which I would have preferred, and connect it to a power bank. Woila! Rechargeable battery powered usb hub in 5 minutes Note: some powerbanks have auto shutoffs if not enough current is drawn. My power bank uses leds and the lights were enough to keep it on without any issues. I also forgot, i wanted to put a switch in so I could still the hub to connect (fewer devices) but still use my laptops usb power, so I dont already need the power bank. I'll bring it to dorkbot tomorrow and do that there if you want to see it in person! Otherwise heres a simple instructions that you can modify if you want to use a powerbank like me https://www.instructables.com/id/Adding-an-external-power-supply-to-a-cheap… I couldnt confirm this but based on my raspberry pi usage in the past, should be safe to use most powerbanks as my assumption is that they are regulated power supplies. Anyone else with any insights id be glad to hear if theres an unforeseen potential danger here but worst case scenario is you dont get quite enough power to all of your devices Best of luck Athan On Sun, Jan 20, 2019, 8:37 AM Ralf Mardorf <ralf.mardorf(a)alice-dsl.net wrote:

On Sun, 2019-01-20 at 15:35 -0800, Ace Path wrote: Don't try this at home! Usually active 4-port USB hubs are inexpensive, too and they usually could be used as an active or passive USB hub, without the need of a switch to connect or disconnect +5V aka VCC aka VBUS coming from the computer. Instead of cutting of the connection from the computer's power, a diode might do the trick. OTOH a diode, such as a 1N4007 drops the voltage, which could become an issue. However, your solution with the cut off power still requires a wall wart with proper regulation, or you anyway at least need to add a 5.1V Zener diode, since adding a voltage regulator could be tricky, too. In the end DIY is time consuming and is asking for trouble. You probably won't damage your hardware, but much likely the DIY thingy won't do the job in all (or at least most) cases. Better buy a cheap active USB hub that was tested to work in all (or at least most) cases by a computer magazine, such as the https://www.reichelt.de/usb-2-0-4-port-hub-with-power-supply-unit-delock-61… .

Jan 20 2019, Ralf Mardorf has written: ... ... Hi Ralf, thanks, this looks promising. I checked the specifications and they sound just perfect for my needs. The system requirements sound a bit off-putting, but then Unix is rarely mentioned. :) Best wishes, Jeanette -- * Website: http://juliencoder.de - for summer is a state of sound * SoundCloud: https://soundcloud.com/jeanette_c * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g * GitHub: https://github.com/jeanette-c * Twitter: https://twitter.com/jeanette_c_s She's so lucky, she's a star But she cry, cry, cries in her lonely heart... <3 (Britney Spears)