Keyboard PS/2 to Parallel converter
brain at jbrain.com
Wed Jan 9 01:59:19 CST 2008
Enrico Lazzerini wrote:
> i need just this, I don't care to see the caps lock led turning on or off!!
> But the schematic indicated to that link, it appear to be a theoric
> I really have not time to testing circuit or verify how it works.
> So anybody has an idea of a pratical circuit working?
Yes, the schematic won't work as-is (it's only 10 bits, and PS/2 uses 11
(start, parity, stop, 8 bits) and as Holger notes, it just delivers PS/2
Set 2 scan codes, which are horrid (voice of recent experience)
But, the design I already sent you will do exactly what you wish. One
Atmel Mega8 (or a Tiny24 would work, though I don't have any here to
test the code). Is there something else you're looking for? I modified
the PS2Encoder design on the web site
(http://www.jbrain.com/vicug/gallery/PS2Encoder) to offer a truly
generic one (all data lines come to a 2x13 header, and the PS/2
connector is already on the board.)
I know the design works, as I tested the code before I sent someone on
the list a version for a FlashWriter II KB interface.
> it's exactly what i'm looking for. So may you give your help? What PIC to
> I have a PS2 Keyboard and when I press the character A I need to have the
> binary code 41H that means 0100 0001B on eight wires plus a strobe line.
> Only in this direction. Is it possible?
Dave's code will work (though you'll need to write some additional 8051
code to do the parallel output, should be trivial.
My code will work, and outputs 41H when a A is sent (Actually, I think
it sends lowercase a, but I can change the mappings in a few minutes if
that's an issue)
Holger is speaking theoretically, without any specific design in mind, I
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