- Michael J. Hammel - https://www.graphics-muse.org/wp -

USB magic

After buying a variety of wifi [1] dongles (to use separately on a Pi, beagleboard [2] and APC at the same time), a collection of USB extenders, three different keyboards, an extra powered USB hub and two new raspberry pi [3]'s (which showed up unexpectedly yesterday even though Element14 made me think they were back ordered and not shipping until the end of the month), I finally found the problem with my keyboard and mouse not working with either the Pi or my BeagleBoard.  Turns out it was rather simple.

Don't plug in a 5V power supply [4] to the OTG port when you also plug in a external powered USB hub to the usb port [5] on the board.  Instead, plug the powered hub into the onboard hub an then connect one of the ports of the powered hub to the OTG port to provide power to the board.

I”m not sure what's happening with power coming from two inputs though I suspect it's a grounding issue.  But I verified both external hubs were working and I'm also able to use the wireless keyboard and mouse via the powered external hub on both the Pi and BeagleBoard.  I'm not sure why the wired keyboard and wireless mouse [6] worked at all originally.  No matter.

Of course, now I have lots of extra USB cables and Wifi dongles.  But hey, live an learn, right?

Related posts