Hi to all our resident electronic geniuses ...... I've got hold of some 2-bit rotary encoders with a pushbutton switch, and I'd like to use them for radio tuning. Twist to change the whole units, push the button and twist to change the fractions.Well, I can easily figure out how to do that with a relay.... here's how I see that working:-http://forums.avsim.net/user_files/72196.gifHowever, relays are bulky and expensive. Is there a simple way to do this switching with a couple of transistors or something similar?Richard

Richard,IMO it would be even better to do this entirely in the software. Since you illustrated it with Photon inputs I'll use the Photon companion application (FSCockpit) as an example ;-)The 2 rotary decoder outputs would be connected to Photon inputs. Those inputs would be mapped to "increment COM1" and "decrement COM1" or similar e.g NAV2, etc.Next the pushbutton would be connected to its own Photon input. Toggling the PB would set a flag in the FSCockpit software that would determine whether the aforementioned functions affected whole units or fractions.No relays or transistors needed :-)I expect most interface software could be adapted to do the same thing but I can only speak for FSCockpit.Hope that helps,ScottScott L. Fausel, VMDIntegrated Flight Systems

Unfortunately I have no idea why I wrote "photon" on that schematic - except that I had just been emailing someone with a question about connecting the decoder boards to a photon - I don';t have a photon, I use Leo's 0x64b input card.Leo sent me an email to reseach something called a J-K flip-flop though, so I'll look into that.Richard

Richard,What software do you use? If your own, you could easily incorporate the technique in my previous post. Or are you using keyboard studio to send keypresses? In that case you do need a hardware solution - but I'm interested to see how one can use a j-k to do this (though no doubt Leo will have a clever solution ). I'd have to resort to a set of 3-state buffers and have the pushbutton simultaneously enable one set while setting high impedance in the other.Good Luck!Scott

Yes, I use KB studio to send keypresses. I'm reading a tutorial on j-k flip-flops, but it's hard going - it seems to assume a level of electronics pre-knowledge I don't have. I'm wondering if, since my panel is displayed on a separate computer connected via WideFS, it might be an idea to connect the 0x64b to that computer instead of to the MSFS computer, and then revise my GA Panel software to enable me to use software logic. Have to give it some thought.Richard

Do Not Use This Design as Critical Components in Life Support Devices or Systems. :-hahhttp://forums.avsim.net/user_files/72536.jpg-Leo

Thank you very much, Leo..... And I'm still going to read the J/K tutorial - it would be nice to understand some of this stuff :-)Richard