Hacking a USB Keyboard

Step 5 Other keyboards and considerations

Some keyboards have sockets. If it does, it saves you a lot of work. What you need to do is get your own socket or set of header pins and solder wires to each connection. Once you have a socket or header pins with wires attached, plug it into the socket on the board. Test it to see if it works by touching a wire on each side together. If it works, glue the header pins or socket into the socket on the board and you're done. It's so simple to connect, in fact, that you may not even want to bother tracing the plastic sheets and just try to figure out the key combinations by trial and error.

Also, there are Mac USB keyboards that allow you to connect other USB devices to the computer through them. I wish I could tell you something more enlightening about the USB connections on those boards, but I can't. Maybe you can do something profound with them. Otherwise, you can just attach wires to it using the method shown in Step 4.

other considerations:

-The USB cable has a tendency to rip off the shift register board. You may want to glue it in place.
-USB devices are 5v 100ma
-Some boards have LEDS attached (see picture). You may be able to send data back from the computer to light them up. If you can control the LEDS, then you can attach low voltage relays to them and have outputs as well as inputs. I haven't tried to figure it out yet, but if you want to give it a go, a good place to start may be here:

http://www.beyondlogic.org/keyboard/keybrd.htm

Comments

[2ManyProjects]

I thought the speculation on the use of the LED to switch a relay was cool, so I did some research. You can get relays that use 3V to energize the relay, which is about the voltage needed for an LED. I also found programs that sets the numlock key on and off and energizes the LED at: http://www.somacon.com/p339.php. I have used this type of hack on a couple of projects, but had always considered keyboards input devices only. Thanks for pointing this out!

[theshades]

Use an optoisolator and turn on any thing you want! DC or AC.

[Kasm279]

gazoontight!

[recordmasta001]

what is the prime use for this?