Home
JAQForum Ver 24.01
Log In or Join  
Active Topics
Local Time 00:39 06 Jul 2025 Privacy Policy
Jump to

Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.

Forum Index : Microcontroller and PC projects : Emulating keyboard

Author Message
Juri74

Senior Member

Joined: 06/02/2012
Location: Italy
Posts: 162
Posted: 08:41am 31 Oct 2014
Copy link to clipboard 
Print this post

Hello!!
Maximite can easily connect and decode a ps2 keyboard.. but could be possible do the oter way?

I would generate key codes when input pins go to 1 or maybe when some analogic input(s) reach some value. This to command a proper program on the pc side using the ps2 connector... In a nutshell Maximite should act as a keyboard!

Have anyone done that?

Juri
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9588
Posted: 01:41pm 31 Oct 2014
Copy link to clipboard 
Print this post

It is something I have wanted to do myself on more then one occasion.
I think the issue is mainly speed in that the uM and BASIC cannot respond fast enough for the host computer to believe there is a keyboard connected, so a uM KB would tend to be ignored by the host computer for that reason.

CG(CircuitGizmos) have a controller that mimics a PS/2 keyboard, but I seem to remember them reporting that this does not work with a PC either.

IF you know exactly what keys you wanted to use on a normal keyboard, your options are really (1) hack a normal working keyboard and run wires from the keys you want via something like a 4066 for isolation, or (2) make use of a PS/2 keyboard controller chip. There was a member here from Germany(sorry, I forget the member) who produced a keyboard emulator with rows of connections so you could just plug into whatever keys you wanted. I will see if I can find the thread. He was not offering PCB's or kits, but did upload the gerbers, from what I can remember, so you could make your own one.
Smoke makes things work. When the smoke gets out, it stops!
 
TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 6269
Posted: 02:18pm 31 Oct 2014
Copy link to clipboard 
Print this post

I have taken a keyboard apart to get the keyboard IC and throw away the keys.
I used a maximite to close the key contacts as required.
This is easy for sending one keypress but not so useful for a string of keys.

Jim
VK7JH
MMedit
 
TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 6269
Posted: 02:42pm 31 Oct 2014
Copy link to clipboard 
Print this post

I might be possible to do with CFUNCTIONS in the MicroMite Mk2
If so, it would be a useful addition to the library.

For those interested in giving it a try,
Here is a description of the PS/2 interface.
http://www.computer-engineering.org/ps2protocol/

Jim

VK7JH
MMedit
 
Synergetic

Newbie

Joined: 14/01/2013
Location: New Zealand
Posts: 22
Posted: 01:13am 02 Nov 2014
Copy link to clipboard 
Print this post

  Juri74 said   Hello!!
Maximite can easily connect and decode a ps2 keyboard.. but could be possible do the oter way?

I would generate key codes when input pins go to 1 or maybe when some analogic input(s) reach some value. This to command a proper program on the pc side using the ps2 connector... In a nutshell Maximite should act as a keyboard!

Have anyone done that?

Juri


In the past have input "keyboard data" from numerous serial devices ( electronic scales , scanners etc)... by using a windows software driver that input the serial data to the Windows keyboard buffer..
Works well ..you can automate keystrokes to ensure you are on the appropriate input window as the drivers can be configures with preamble and post data based on the serial data input to the driver...
 
Frank N. Furter
Guru

Joined: 28/05/2012
Location: Germany
Posts: 946
Posted: 11:32pm 02 Nov 2014
Copy link to clipboard 
Print this post

Hi Juri,

you can try to use my keyboard emulator from this thread. (Grogster mentioned it...)

It works also with PS/2. You should be able to use a Micromite or Maximite to "push" any button with a AQY210EH PhotoMOS relays (or with a two Mosfet equivalent circuit)

Frank
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9588
Posted: 12:13am 03 Nov 2014
Copy link to clipboard 
Print this post

Ahhhhh - Tim Curry! I thought it was you!
Smoke makes things work. When the smoke gets out, it stops!
 
Juri74

Senior Member

Joined: 06/02/2012
Location: Italy
Posts: 162
Posted: 06:07am 15 Nov 2014
Copy link to clipboard 
Print this post

Hello all again
Using a keyboard encoder chip could be an idea, however like TassyJim said it will start to be very hard if i want to send a series of keys (or simulating simultaneous button push, like ctrl+alt+del)

any more info about that CFUNCTION for Micromite mk2?
 
G8JCF

Guru

Joined: 15/05/2014
Location: United Kingdom
Posts: 676
Posted: 06:12am 15 Nov 2014
Copy link to clipboard 
Print this post

Look here http://www.g8jcf.dyndns.org/mmbasicmkii/index.html
The only Konstant is Change
 
Print this page


To reply to this topic, you need to log in.

The Back Shed's forum code is written, and hosted, in Australia.
© JAQ Software 2025