keyboard controller

[kb]

Can someone help me out w/ a quick question:

I am creating an "automatic" keyboard to drive some old software that
only provides a keyboard interface for some camera control.

I have extracted a keytronics microcontroller from a ps/2 keyboard and
would like to simulate key hits by using an algorithm in another
microcontroller (like a basic stamp) that creates the continuity
normally provided by the keyboard contacts.

Question: How do I create the continuity using a basic stamp?
Certainly an EM relay would work, but is too slow and noisy. Could I
use a switching NPN transistor or would the voltage drop across the
transistor be to large for the keytronics IC to see continuity? What
other options should I consider? small SSR?

thanks much

 

[Tim Wescott]

<kb> wrote in message news:dspb50ppuof6c1lrqtj6iiou4269f9o2kf@4ax.com...

Can someone help me out w/ a quick question:

I am creating an "automatic" keyboard to drive some old software that
only provides a keyboard interface for some camera control.

I have extracted a keytronics microcontroller from a ps/2 keyboard and
would like to simulate key hits by using an algorithm in another
microcontroller (like a basic stamp) that creates the continuity
normally provided by the keyboard contacts.

Question: How do I create the continuity using a basic stamp?
Certainly an EM relay would work, but is too slow and noisy. Could I
use a switching NPN transistor or would the voltage drop across the
transistor be to large for the keytronics IC to see continuity? What
other options should I consider? small SSR?

thanks much

It would probably be easier to just make your basic stamp send keycodes.
The protocol used by PS/2 keyboards is out there on the network -- you'll
have to search for it with google or whatever.