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Topic: Has anyone tried USB to PS2 keyboard adapter? (Read 182 times) previous topic - next topic

GoForSmoke

I see them on the net for $1 ea (+ S&H) and wonder if that's a surplus then it's gone price or can happen again price?

Does it take a full-spec&speed USB host to read a USB keyboard?
Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

uxomm

As far as I know, the "magic" is inside the keyboard or mouse itself.
The adapter is small, and passive, and there is no chip inside.

I have a mouse, which claims to be "USB/PS2" and comes with it's own green colored passive adapter plug. The mouse itself, recognizes the signals are coming from USB or PS/2 and adapts itself accordingly.
The fact the green passive adapter is bundled with the mouse, is proof the mouse is a dual-protocol type design.
Same with keyboards.

I once disassembled one of those "adapters" and found nothing but a USB plug, a PS2 plug and 4 wires...

There are "real" adapters with a chip inside, but they do cost more than $1.
Always decouple electronic circuitry.

terryking228

Hi,
In my experience, if you want to connect an older PS2 keyboard like IBM Model M etc, and you want a PC with Windows to recognize it as a USB keyboard you need an adapter with a chip doing translation.
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

GoForSmoke

I'm seeing if there's a cheap way to connect cheap USB keyboards to Arduino as TTL serial.
Keyboards do have a chip but it talks to USB which isn't so simple from what I've been told.

I've seen projects that pin-hack mice chips to let Arduinos read particular mice well. 
Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

uxomm

It is pretty easy with older PS2 keyboards (or mice). I have used it several times in projects.

Or you can use one of these dual-protocol keyboards (PS2 / USB with passive adapter to PS2) - my experience is: connecting it to Arduino (with it's passive PS2 adapter) does not work with *every* keyboard but with most of them.

For "USB only" keyboards you need an USB host shield or an active USB to PS2 adapter I suppose.
If you find a cheaper solution than (the expensive) USB host shield, let me know, I am really interested. :)
Always decouple electronic circuitry.

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