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Re: Mouse and keyboard over GPIO?

Posted: Tue Oct 18, 2011 7:22 am
by RITRedbeard
In an interest of saving the USB ports, is there a method for Linux to hook up mouse and keyboard over GPIO/as serial devices?

Re: Mouse and keyboard over GPIO?

Posted: Tue Oct 18, 2011 7:33 am
by jamesh
Personal opinion only, but I think the work involved in doing this would be extensive - much cheaper to buy a hub!

Re: Mouse and keyboard over GPIO?

Posted: Tue Oct 18, 2011 7:44 am
by tufty
It might be worthwhile if:

a - you have a useful serial input device (The "stowaway" serial keyboards for Palm etc spring to mind, given the size of the Pi)
b - you have an input device that uses a non-USB connector and which can't be connected as a HID device using any reasonably priced adaptor (think Model M or TSO workstation keyboards, ADB-connected Wacom tablets, etc)

Basically, if you have a device that you absolutely *must* have connected and which can't plug into a USB hub one way or another. Of course, you'll need to know the protocols used by the device, you'll need to protect the Pi's GPIOs on the physical side, (not that we know how many there will be yet) and you'll need to write and maintain a kernel-side driver for the device.

Not easy, in any sense of the word.

Simon

Re: Mouse and keyboard over GPIO?

Posted: Tue Oct 18, 2011 12:12 pm
by ukscone
i'll be looking at using keyboards from old computers (Camputers Lynx, Tandy Model100,....) on my Raspberry Pi (when I get one) so using GPIO and the gpio-keys kernel module will probably be the easiest way to go.

Re: Mouse and keyboard over GPIO?

Posted: Tue Oct 18, 2011 12:54 pm
by TonyD
You could bit-bash a PS/2 interface using the GPIO. The GPIO is 3.3V and PS/2 is a 5V interface so you'll need to have some 3.3V to 5V signal conversion going on and you'll need to find a PS/2 keyboard and mouse.