I'm working on making a keyboard emulator from old key board parts which should do the job but I dont know how to handle controls that are traditionally managed by switches

for example landing gear is controlled by pressing the "g" key, however I want to make it switch activated. But hooking up a switch in place of the key will mean the computer will recognize it as holding down the "g" key while the switch is on. does anyone know how I can remedy this situation? possibly building some kind of microcontroller that lets the emulator know that a switch means to send a signal just once? or are there switches available that appear to be switches but actually function more like push buttons?

Hi,

You do get things like toggle and rocker switches that are spring loaded to stay in the middle position. When you force them one way or the other you make a contact. When you then release it, it will return to the middle off position.

The type of switch is often referred to as a (mom) - off - (mom)

The other alternative is to make up a small circuit that produces a short closure of a solid state relay which becomes your key switch replacement whenever a switch attached to it changes position. In this situation you'd use an (on) - (on) switch.

GrizzlyT has a circuit and PCB layout on his site here:

http://home.comcast.net/~timothyboldt/relay.html

I'm quite sure he wouldn't mind you using it.

Hope this helps,

Andy

What Andy said, but you might want to consider whether you actually need a momentary switch - DCS for example has no problem with continuous inputs from switches.

(Granted, I don't know much about keyboard-based setups and the complexities of using matrixed keys, but just thought I'd try and cut a potential Gordian knot for you)

Edit: To elaborate a bit, check out the control options to see if there are "gear up" and "gear down" inputs instead of just "toggle gear." If there's just "gear up" and you're using an ON-OFF switch, you'll just need a bit of simple .lua editing to make the "OFF" setting recognized as "gear down."

Not at all....It was just my take on a schematic that has been floating around for awhile.

BTW - You can actually take the "circuit" option in two directions.
The first is the relay based circuit that Andy already pointed out. The alternative is an optocoupler based circuit.

I started doing some work on that, too. You can find it here. opto drawing
I played with it a bit, on a breadboard, but never etched any versions (Mostly to do with the spare parts I had laying around ).
So, there's only the .dwg drawing....sorry!