Bypass The Binary Code
I was finally able to put in the switches and hook up the controls tonight/this morning.
Here it is. The jukebox software started right up and everything worked perfectly on the first try.
Closeup of the buttons. The protective coating is still on the plexiglas.
Here’s the rat-nest of wires in the back. I don’t have cable ties on anything yet. The keyboard encoder is just taped to the side with double sided foam tape. The terminal strip is screwed to the bottom.
So… with the screen strapped to the back of the craptop, I’ll need some way to control the jukebox. Cheap momentary pushbuttons from RadioShack seemed like a good way to go. This picture isn’t a finished piece, but it shows the buttons wired up into a spare piece of plexiglas for testing.
The buttons do no good without something to connect them to. So I dismantled a keyboard, de-soldered the connectors, and soldered a ribbon cable into the holes. I connected the other end of the ribbon cable to a terminal strip so it’s easier to wire up the buttons.
Having a terminal strip wired up to a keyboard encoder doesn’t do any good if you don’t know which pins to short together to create a keypress. I dug out my scanner and scanned both layers of traces for the keys. I then used my image manipulation program of choice and made the traces colorful and figured out which key shorted which pins.
The keyboard encoder pinout is probably different between different models/brands of keyboards, so there isn’t much point for me to post that here. Another method of figuring out which pins go where is to partially disassemble the keyboard and use a multimeter on continuity test with alligator clips to figure out which key shorts which 2 pins. Yet another method is just plugging the keyboard encoder into the computer and shorting pins and seeing which keypress it caused.
The internet is filled with very helpful people. Almost any project you can imagine has been at least attempted by someone somewhere. These links might be useful:
This link has a great explanation of how to use a keyboard for arcade controls.
http://www.dribin.org/dave/keyboard/one_html/
This is an example of someone that has already done what I plan to
http://www.hellspark.com/dm/mame/deprecated/keyboard/
That’s the rough idea.
I have a laptop with a broken hinge that refused to run the latest version of Xubuntu. It annoyed me and was approaching useless.
Here’s the plan:
Spare Parts (Better than the money-cost kind)
New parts (The money-cost kind)
Mix with a healthy dose of free time and cook in the basement until completed.