Wired USB Keyboard/Mouse to Bluetooth bridge (HID Relay)
Year ago I was so desperate to convert my beloved mechanical keyboard to wireless (most built-in ones do not have the kind of right tactile feel I wanted) so I was damn close to building an embedded wireless HID/keyboard on my own (there’s a Hackaday Tutorial for HC-05). Now Handheld Scientific makes it.
Sometimes Windows recovery mode do not have the ‘Startup Repair’ option like this below
I don’t know under what condition it won’t show up (sometimes I plug the system drive to be repaired in a computer, it shows up, at least for Windows 2008 R2), but you can selection Command Prompt (always available) and go to X:\sources\recovery and run startrep.exe to launch the repairing tool.
I’ve bought many powered USB hubs, even the expensive industrial version like Startech, but they never work reliably when I connect multiple devices that draws quite a bit of power. The behavior is the same (erratic when too many power drawing devices are active within one hub) whether I supply the hub with external power or not.
I suspected the USB hubs wasn’t wired in a way that the USB hub controller understands that I want to have the hub self-powered (powered from an external source like a wall wart instead of drawing the 5V from the USB upstream cable). So I opened up my StarTech and it looked like this:
On the top left corner, there’s a jumper to set the USB hub to use self-powered instead of bus-powered (default out of the box). I switched the jumpers and the board no longer takes power from the upstream bus and the lights won’t light up until I have the local power connected, which confirms it’s working as a self-powered hub.