Robotic Keyboard Tester 1

[ChefGroovy]

I work for a keyboard manufacturing company. We currently use pneumatic robotic "heads", with 132 individual plungers to test each key and its associated scan code. All ran on IBM XTs(!!) with dos 3.3. This stuff is old old old. The interface to the robots is two custom built cards, circa 1983 or so.

I am currently working on a new system to control the head via the parrallel port. And upgrade the computers to 486. I have the circuit built that will fire all the plungers and all is well and good, but I can't decide how to read the scan codes.

The real question is, anyone know of a circuit where I can read the scan codes of a keyboard via the parrellel port? I know I could use the regular keyboard port to do it, but then when a keyboard is under test or being debugged I wouldn't have a keyboard. Would much rather do it over the Par Port.

I could also use the mouse port to read the scan codes, which I do on the "manual" audit tests we do. But this is still not as neat and self contained as it should be. Eventually would like whole system to be on windows written in vis basic, so mouse port would not be availiable.

Any help or input greatly appreciated

Dan Shaffer
jdshaffer@qx.net

 

[Lewish]

Well, the keycodes are sent to the PC as bit banged 2 wire serial data. There is no reason you couldn't do this over 2 wires of the parallel port. Just make sure you are using the advanced port driver and you use pins that are intended for inputs on the PC end.

 

[jmengineer]

A possible way is to read the keycodes with a microprocessor and send them to the PC via a serial port. Get an Atmel AVR microprocessor, such as on this AT90S2313 Development Board available at

http://www.futurlec.com/ATDevBoard.html

for about $20. Download the evaluation version of the BascomAVR BASIC compiler from

http://www.mcselec.com/download_avr.htm

The compiler has support and detailed instructions on connecting PC keyboards. It should take about 6 lines of code to complete the application.

 

[nbucska]

Multiplex the two KB-s ( the PS-s and the DUT ) and
select one by the program <nbucska@pcperipherals.com>