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Very low cost rotary encoder driver chip.

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For all simpit builders in need of a cheap solution as regards rotary encoders I must say that the solution I got from the www.hagstromelectronics.com guys using their USB keyboard encoder KEUSB36 and two microcontroller is absolutely fantastic. I can know run 16 mechanical rotary encoders for about l20$, may be 130 inclucing shipping cost ( I am fench) Compared with some companies asking 79,50 $ for ONE card driving ONE rotary. (NO COMMENT)Write to them and ask them for the solution tested by Roger.Kind regardsRoger

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That's very nice Roger, That was the first step I was planning to do-- buying one from company, but I realize it'd be much cheaper if I would just build one of my own by using 16 encoders-- 8 of IC7474, 8 of IC 7414, and 4 of 74244. The total of cost of doing this is about $20. It works perfectly for EPIC and PIC board.

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I believe there is always a way to get things cheaper. I am happy for you. I do not, and I believe lots of cockpit builders do not have enough knowledge about electronics and programming in order make such good deals.I know that the PIC used by Hagstrom is an ATMEL AT89C51 and cost 1.50 $ and drives 8 rotaries, what makes 3$ for 16 rotaries and works well too for Epic card. You just have to programm the controller and design the circuit. I payed 24$ for that because I am filmmaker and not electronicians.But the smart electronician would have made a better deal than you using the Hagstrom solution.The intend of my mail was simply to help some guys like me with minimal knowledge in electronics and programmation, the one who are normally caught by some companies selling cockpit building products as they were made from Gold.Kind regardsRoger

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Roger, I have to agree with you, please disregard my previous statement I wasn't trying to put myself in top. What I was implying that those chips I got it from radio shack would conventient and cheaper, or quickest way for anyone who is in fire to build up the encoders.

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HiIs it really neccesary to use the elektronics mentioned in this thread? I just read the FSUIPC for programmers doc (Pete Dowson) and he explains that rotary encoders can be put to joystickbuttons. He also give some examples how to do this in the FSUIPC.INI file. You can put 16 joysticks to WIN (UBS perhaps more?) So you have 16 buttons to use 8 rotaries.I just received my aerosoft MCP hardware so I need only a few rotaries for the radios and I will try that way.Norbert Boschgood luck

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Hi Norbert,That would be rather an excellent news, but after my experience I would says that you really need a circuit able to make the difference between signal A and signal B of an rotary and manage the " bounce" of the rotarie. I have tried to put one directly on a keyboard encoder. Signal A was programmed to key "A" and signal B to key "B".Pulsing with the rotary from right to left I got "ABABABABABAB" as response and from left to right I got the same response too. IMHO joysticks buttons seems reacting like keyboard strokes. Dont ask me why this happen so, I not electricians and may be is out there a fellow simmer who may explain that more precisly.Kind regardsRoger

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>rotary and manage the " bounce" of the rotarie. I have tried >to put one directly on a keyboard encoder. Signal A was >programmed to key "A" and signal B to key "B". >Pulsing with the rotary from right to left I got >"ABABABABABAB" as response and from left to right I got the >same response too. >IMHO joysticks buttons seems reacting like keyboard strokes. >Dont ask me why this happen so, I not electricians and may >be is out there a fellow simmer who may explain that more >precisly. That's exactly how rotary encoders are supposed to behave :)There is one thing makeing the difference, but a simple keyboard encoder can't detect it: steps.Usually a single encoder step (the snap you feel when you turn the knob) corresponds to one of the below:ABABorBABAdepending on the direction you turn the knob.How to interpret this?In order to distinguish the direction of rotation, you need something that informs you of this.In this case it's the phase.If you hook the rotary to an oscilloscope (if you don't know what it is: it's an instrument with a monitor, on the monitor it shows the waveforms of the signals you put in it, to keep it simple ;)) you would see two almost rectangular waveforms.One ahead of the other of 90

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Hi,It seems convincing and if I understood correctly I cant see how FSUIC could manage directly rotary encoder connected on joystick buttons, or do I am wrong ???Kind regardsRoger

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>Hi, >>It seems convincing and if I understood correctly I cant see >how FSUIC could manage directly rotary encoder connected on >joystick buttons, or do I am wrong ??? With an hardware fast enough, it would be possible for a software to do the same thing, yes.Altough i've never tested this fsuipc capability myself.Best regardsClaudio

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Would you have a circuit diagram of that? I designed one that works OK but could be better. You've used some different components to me, my circuit diagram is here http://homepages.ihug.com.au/~pholt/panel.htmlI found I needed one 7474 per encoder, are you using one for two encoders?Peter

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if i understand the following diagram correctly one gets a signal on pin a (Kanal A) when rotating counterclockwise and nothing on pin b (Kanal :(.the reverse is true when rotating in a clockwise direction.should this not make use of a circuit unnecessary?confused!the rotary goes for 28 dollars a pop!to be found at http://www.buerklin.de enter G083.500 into Suchbegriff and voila!http://www.simpit.de/screen/buerklin.jpg

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Surely this kind of switch exist, but as you noticed they are really costly.They come with an integrated circuitry that does the signal elaboration i explained above.But you do pay really a lot for such a feature.If you can make your own circuitry (wether you are able to conceive it or you find it in the web) you will have lot cheaper device.A normal rotary encoder is sold at around 4$ or so.This you tell us, at 28$.That's what the difference is ;)

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Hi,That's the simple circuit I used. The IC is the same as the one used for the KE72 and the KEUSB36 of Hagstromelectronics.com but with a different program. It drives 8 rotaries and I payed for about 25 $. Add 8 rotaries for 1,4$ of Panasonic and sold by DigiKey.com. It's a bill of 35 $ for 8 rotaries and that circuit works with any Keyboard encoder or Epic Card. I have two circuits-16 encoders working very well.Regards Roger

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Hi Roger, I got one of those chips from Hagstrom but when I set it up in a test circuit with the Panasonic encoder, I found that while it was correctly determining the direction of rotation of the encoder, I was getting 2 output pulses for each detent on the encoder. This meant that for each detent, there were 2 keystrokes sent by the KE72. Made it difficult to use in radio tuning etc. Is this happening with yours?I let Hagstrom know what was happening and I'm wondering if they have made changes to the code.Peter

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