Simulating Keyboard with stamp
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Posts: 46,084
Uli-
I've not done this, but it seems do-able and I'd try it by using
your Stamp and your keyboard in parallel. Perhaps even find a place
within your keyboard case to mount your Stamp (there is +5V easily
available at PS/2 pin #4). This lets your keyboard handle the
initialization and any other manual inputs you may wish to provide
from it.
After your PC goes through its power on reset and peripheral
initialization your keyboard will almost certainly be using scan
code set 2, so your Stamp must also. See Appendix 1 of
http://www2.national.com/an/AN/AN-734.pdf for a listing of scan
codes for the various keyboard modes.
Your Stamp program would send each data byte packaged within a
synchronous serial, 10-bit unit: a low start bit, eight data bits
LSB first, an odd parity bit and finally a high stop bit. Each bit
is sampled during low clock levels.
The clock and data lines, PS/2 pin #'s 5 and 1 respectively, are both
open drain (i.e., LOW for a low, INPUT for a [noparse][[/noparse]pulled-up] high), so
they can be shared between your keyboard and your Stamp--you won't
have a destructive conflict if you never set the pin HIGH. This also
means you won't be able to use SHIFTOUT so you'll have to write a
simple synchronous serial output routine yourself. PS/2 pin #3 will
serve as your power and signal ground.
In broad terms, that's one approach that's probably worth a try.
Sounds like fun. Hope this helps some.
Regards,
Steve
ulibasic wrote:
> Hi Stampers,
>
> I would like to replace the keyboard of my PC by a stamp...
I've not done this, but it seems do-able and I'd try it by using
your Stamp and your keyboard in parallel. Perhaps even find a place
within your keyboard case to mount your Stamp (there is +5V easily
available at PS/2 pin #4). This lets your keyboard handle the
initialization and any other manual inputs you may wish to provide
from it.
After your PC goes through its power on reset and peripheral
initialization your keyboard will almost certainly be using scan
code set 2, so your Stamp must also. See Appendix 1 of
http://www2.national.com/an/AN/AN-734.pdf for a listing of scan
codes for the various keyboard modes.
Your Stamp program would send each data byte packaged within a
synchronous serial, 10-bit unit: a low start bit, eight data bits
LSB first, an odd parity bit and finally a high stop bit. Each bit
is sampled during low clock levels.
The clock and data lines, PS/2 pin #'s 5 and 1 respectively, are both
open drain (i.e., LOW for a low, INPUT for a [noparse][[/noparse]pulled-up] high), so
they can be shared between your keyboard and your Stamp--you won't
have a destructive conflict if you never set the pin HIGH. This also
means you won't be able to use SHIFTOUT so you'll have to write a
simple synchronous serial output routine yourself. PS/2 pin #3 will
serve as your power and signal ground.
In broad terms, that's one approach that's probably worth a try.
Sounds like fun. Hope this helps some.
Regards,
Steve
ulibasic wrote:
> Hi Stampers,
>
> I would like to replace the keyboard of my PC by a stamp...
Comments
I would like to replace the keyboard of my PC by a stamp, the stamp would
then pretend to be a keyboard and send keys to the PC. I have been working
with manipulated keyboards and it works but I am looking for a more elegant
and simple solution, especially since I am using stamps in every project
anyway...
Thanks for your help, Uli
[noparse][[/noparse]Non-text portions of this message have been removed]
PIC16F84. It seemed pretty trivial, a little protocol dance at power up... Try
looking on their sight, maybe that have it online, and see if you can get ideas
from it (even though it's not to a stamp).
Kevin
ulibasic wrote:
>
> Hi Stampers,
>
> I would like to replace the keyboard of my PC by a stamp, the stamp would
> then pretend to be a keyboard and send keys to the PC. I have been working
> with manipulated keyboards and it works but I am looking for a more elegant
> and simple solution, especially since I am using stamps in every project
> anyway...
>
> Thanks for your help, Uli
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
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