Re: Keyboard Hacking - A First


[ Follow Ups ] [ Post Followup ] [ Build Your Own Arcade Controls message board ] [ FAQ ]

Posted by Jim K on 17, 2000 at 11:07 PM:

In Reply to: Keyboard Hacking - A First posted by Malberg on 17, 2000 at 10:12 PM:

: This is my first attempt at hacking a keyboard. I've read many messages on the BYOAC and looked at tons of examples. I'm hacking a comqaq keyboard with the windows keys on it(newer model). I've taken it apart to find out that the mylar actually goes into the PCB via connectors that resemble ISA slots on the motherboard. I've read that you can solder the wires underneath the board, and using a multimeter to make sure that none of the solder spills to the next lead, to short out the PCB. I just have a couple of questions for anybody out there, and I would appreciate some input, here are my questions:

: 1) Can I get a brief intro on how to use a multi-meter or is there a website that explains the use of one.?

: 2) This PCB has 20 leads by 8 leads does that sound right? All the examples I've seen they were 19 by 8, 18 by 9, 16 by 8 etc etc?

: 3) I plan to use an alligator clip with a wire to figure out the matrix for the keyboard testing each pair of contacts on the PCB ie x1,y1..x2,y2 etc. Also the LEDs for caps, num, scrl locks are not on the PCB, but on the keyboard itself. Is this going to present a problem while I'm solving for the keyboard matrix?

1) The multimeter is easy... I'm assuming you have one... all you have to do is set it to ohms (the omega symbol) and put one end on the key and the other on the pcb. If you meter reads 0 (or very close to it) you have continuity and have found a trace. If you need more info than this post and I will reply.

2) From my experience ( 3 keyboard hacks) it doesn't matter how the pcb is layed out. When I traced all of my matrices none of them matched the pcb layout. So just test it and your matrix will show itself regardless of how the prongs are layed out. Most of the time pcb's are layed out for ease in manufacturing and not by electric characteristics. You can solder directly to the board but this isn't the easiest task for the novice. I would say get the pinout of your keyboard encoder and then solder directly to the chip.

3) The led's can give you problems in the fact that if you accidentally hook up your led's to the data line (wiring the led as a keystroke) you can fry your motherboard. LED's are tricky and I would say stay away from them completely... but if you think they are that cool (personally I don't) then just be absolutely sure of their trace.

Hope this helps,

Jim K
Jim's Arcade Joystick


Follow Ups:



Post a Followup

Name:
E-Mail:

Subject:

Comments:

Optional Link URL:
Link Title:
Optional Image URL:


[ Follow Ups ] [ Post Followup ] [ Build Your Own Arcade Controls message board ] [ FAQ ]