By inspiration from the flight sim genius Mr. Kev Saker, I decided to try a brief suggestion given by him in one of his articles as it relates to hard wiring the entire sim to a keyboard...and it worked. By doing this, you will need NO solenoids whatsoever. The cost of the entire electrical interface (not counting wiring or switches) is a mere $12. I will attempt to describe the concept behind this new electrical interface so that you can use this technique with any aircraft you'd like.
Before we begin, I must remind you of a point that will make this interface, dare I say, easy. Everything is done exactly the same as specified in Kev Saker's
reports,
except instead of connecting the wires from the micros (lever switches) to solenoids, they will connect to the slots on the keyboard card as I will explain later. Also remember that the keyboard supplies its own power supply so you will not need to worry about any manual power supplies unless you intend to use indicator lights as well. VERY IMPORTANT if you plan to use indicator lights, please do not put them on the same switches and lines as the keyboard card or you will most likely blow it out. Figure E1-4 shows a proper technique for connecting indicator lights without disturbing the keyboard card.
To construct the electronic interface for your simulator, you will need a keyboard, switches (use the same switches specified by Mr. Saker for each part), and lots of thin wire. The type of each of these parts that you will need is:
Keyboard: I would advise that you use the AT style 5-pin keyboard rather than PS/2. If you have a PS/2 style port on your computer, you can buy an adapter from most computer accessory retailers for less than $5. The reason I would advise that you use this style of keyboard is that the slots on the keyboard card are much easier to work with and require no soldering etc. to connect wires, unlike most newer PS/2 keyboards. Everything works exactly the same using a PS/2 keyboard though, so if you would rather use one, go for it.
Switches: Use the same switches that Kev Saker specified in his reports for each component.
Wires: Use reasonably thin wires for this interface to prevent a voltage drop. Try not to use wire too thin or you may chance the wire melting or overheating. The optimum wire size is that of speaker wire. If you observe the dual wire connecting the speakers to the stereo, one of the two twined wires should be the optimum size for the interface. The wire you buy should be solid (not stranded) if possible and you can actually use dual wire to reduce the number of wires flailing around inside your sim.
Constructing the Interface
You will now need to strip the keyboard down until you are left with three transparent sheets, an electronic keyboard card and a long connector cord. Do not remove the plastic sheets yet because they play an EXTREMELY important part in this interface. The part of the keyboard that you will need to be concerned with are the two slots that the transparent sheets are connected to. By connecting a wire from the "short" slot to the "long" slot, you can create any keyboard output that you'd like. Each keyboard has different signal requirements (slot combinations) and that is why you'll need the transparent sheets to determine which pins on each slot control each letter. You may also want to keep the keypad so that you can determine which node on the sheets corresponds to the letter you want.
The sheets work like a schematic and work as follows: If you want to create the letter "g", you would directly line up the transparent sheets and place them in an upright position. Now locate the node which corresponds to the letter "g" as in figure E1-1 (place the sheets on top of the keypad to help locate the node if needed). Somehow, remember which node the letter "g" uses on the top and bottom sheets. You can find out which node to use on the bottom sheet because it will be directly below the proper node on the top sheet if you line the sheets up. Now, on the top sheet, locate the node that you just marked/remembered for the letter "g" and follow the line that it is on, until you reach the slot on the keyboard card as in figure E1-1. You may need to lift up the top sheet so you won't get sidetracked by the bottom sheet. Now, note which pin the line ended at, and repeat this process for the bottom sheet. These two values represent the signal required to create the letter "g".
Now to send the signal for this key to the computer, all you need to do is take a wire and place one end in the pin you marked on the short slot, and place the other end in the pin you marked for the second slot as in figure E1-2 (once you remove the transparent sheets). As you can see, figures E1-1 and E1-2 are exactly the same except one uses the transparent sheets, and the other uses wire and a micro switch. That's it. You have just created the letter "g". It is a hundred times easier every time you do it and you can now repeat this process for each switch and button you plan to use. Now, you may safely remove the transparent sheets. The middle sheet, that has nothing on it, is useless and can be discarded at your own leisure. There are a few major points that I must make in regards to the interface before you begin adding a lot of buttons.
Because many letters will use any given node, and the nodes are very small, it will be necessary to construct extensions as shown in figure E1-3. These are nothing but strips of wire with one end connected to a pin and the other end left free. This will allow you to add as many wires to each slot as necessary. Whenever you want to connect a switch to a particular pin on the keyboard card, you will instead connect it to the corresponding extension wire by shaving off enough of the insulation on the extension to solder or connect the desired wire.
Figure E1-4 shows how the landing gear panel would generally look using indicator lights, and using Kev Saker's basic switch setup. By connecting the up and down micros to the proper extension wires on the keyboard card, you can easily create a working landing gear lever. You can add indicator lights to the panel as well by connecting the gear lever to a DPDT (Double-Pole Double Throw or 6 pole) switch and connecting each of the indicator lights to extension wires from that switch. Kev's plans used some sophisticated techniques and so I will refrain from repeating them here. If you would like to use Kev's detailed landing gear technique, you can refer to part 18 of his report. The only difference is that the wires that were designed for the solenoids now run to the keyboard card. Just remember to keep the indicator lights' power supply off the same lines as the keyboard card.
Also, for those who want to be able to use this massive simulator with more than just one flight simulator, there is a way to connect each switch to more than one keyboard button, then be able to personally control which output is created. It uses an electronic component called Silicon Controlled Rectifiers which are a type of thyristor. These are essentially solid-state, electrically controlled switches and can allow decisions to be made by your simulator. I haven't drawn up complete plans for this interface yet, but will try to do so and release it with Mr. Saker's next report (if he so graciously allows!). You will also be able to get the diagrams directly from me very soon via e-mail at AirPanther@aol.com. The only thing is each thyristor costs anywhere from $0.30 to $1.00 and each switch would require 4 thyristors, which could cause for pretty hefty prices, but may be worth it if you have two sims that you really enjoy or if only a couple of buttons are different between the two sims.
Any questions, suggestions, or comments about the electronic interface can be sent to me, Robert Prather, at
AirPanther@aol.com
and will be answered A.S.A.P. You can also write to this address to become part of the electronic interface mailing list to receive info on the latest breakthroughs on this electronic interface. Also, if you are having difficulty finding any electronic component, write to that e-mail address and I'll tell you how to get the parts you need at a low cost, from a well know company, in a few days, through the mail.
