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Guest darrens

Help needed connecting rotary decoder (to photon)

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I've just received my rotary decoders from Richard Alty (many, thanks, Richard). I'm struggling, however, to make sense of it all since I've never used rotaries before. I have attached a diagram for somebody to point me in the right direction. Perhaps somebody can draw on it to show how the wiring goes.#1 I'm not sure which is the ground on the power input of the decoder.#2 I understand that the decoder can accommodate 3 encoders. This makes sense since there are 3 banks of 4 pins (JP1, JP2, JP3) and 3 banks of 3 pins (JP5, JP6, JP7). I'm guessing that they are the inputs and outputs of the decoder. But which is which?#3 How do I connect a rotary encoder to the decoder (more precisely, how do I connect all 3?). The rotary encoder has 3 outputs but where do they go?#4 The output of the decoder to the input of the photon I'm assuming carries one ground with the remaining connecting as a normal switch?If somebody can give me an idiots guide to connecting everything together I wil be eternally grateful.Best wishes,Darren Sugdenwww.sugden.karoo.net (A320 Cockpit Project)http://forums.avsim.net/user_files/71516.jpg

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Darren,I'm going through the same struggle as you. Scott is working on how to connect to the Photon input module. He sent me a few directions last night. You may want to email him directly with your questions.Richard

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Thanks for that, Richard. I'll do that.Regards,Darren

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Hi guys, I'm the designer of that decoder monstrosity, but the PCB was generated by someone else during manufacturing from my schematics so I cannot say with certainty what connection goes where at this point.I've asked Richard Alty to send me one and I will write up a quick manual on how to use/connect it once I figure it out myself by reverse engineering my own design. :-zhelpMy apologies to everyone who is struggling with those blasted things!-Leo

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Ok this is now past the humorous stage. How in the world did this rotary decoder board get manufactured, assembled, and "tested" if no one knows how to connect it to all the supported input devices? Did no one think that documentation would be necessary for those using the board? Richard

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Did you buy this board from Richard Alty or did you build it yourself?This design was offered by me to the community as a DIY (see zip file floating around with schematic). Richard offered to manufacture a small quantity with my consent at COST for everyone since I had no intention of producing any PCBs. He's not making any profit on these boards and took all the time to do this for free as have I!He did agree to write documentation for it, but he is away on business trip at the moment so I offered to do it myself asap.If anyone else has a problem with these then please contact me and we can work something out!-Leo

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Hi Leo,I purchased the boards from Richard Alty. I received them a day or two ago. I've been emailing Scott and seeking his help with connecting the decoder boards to his Photon input module. Any idea how long it will be before you complete the documentation. The decoder boards are collecting dust right now.Thanks for your help,Richard

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Hello, Leo.I think I have connected it correctly to the IFD's Photon board but it's not really working. I can get it to change a variable e.g. heading by one 'notch' sporadically - but then it takes quite a few turns of the encoder for it to happen. I've checked the voltage into the board and the output pins of the board and they are fine.Very frustrating.I've attached a diagram how it's connected.Best wishes,Darren

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I've sent you mail. Please check your email (unless its been changed).-Leo

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Leo,I don't have a schematic of either board, so likely I'm talking through my hat....The REDec circuit is designed to be able to connect to a scanned matrix, as I recall. It basically appears as a set of contacts???The Photon board is a direct input, logic-level device???If so, there is little pulling the input signal high other than the Photon input gate's input impedance. It will drift high, but any stray capacitance on the input will slow that down.If this is right, then connecting a 1K resistor from each photon input to +5 should make a big difference.Mikewww.mikesflightdeck.com

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Hi Mike,Yes, the Photon input board is based on the same mux chips as mine and they have a pull-up res incorporated into the board's design for this purpose (good catch though Mike). The decoder does work on these (Photon & my USB stuff), its just that the correct pin on the transistors must be connected to gnd and this is probably what's causing so much trouble for everyone...unless I missed something else.Unfortunately I don't have any of the new boards to specify which pin goes where but will update everyone asap once i have one in my hands.As far as FSBUS input is concerned, I urge everyone to use REDEC which uses analog switches for the output. (Everyone, please read me "Recall" message about this)Thanks Mike.Sorry to everyone who

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I posted a 'how to connect it' in another thread on this forum yesterday. How you've wired it in the diagram is exactly how I wired mine to one of Leo's 0x64b boards, except that that board has no power out, so I'm using a separate power supply, with the grounds connected together. I connected one of the boards to the 0x64b, and used it in MSFS, succesfully. All the other boards were tested by connecting a pair of LEDs across the output pins of the decoder board, and then turning the rotary in both directions - one LED flashed as I turned it clockwise, the other one when I turned it counterclockwise.When I get home I'll test the other ones I still have 'live' and see ifI get the same problem

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RichardL:>>How in the world did this rotary decoder board get manufactured, >>assembled, and "tested" if no one knows how to connect it to all >>the supported input devices? Did no one think that documentation >>would be necessary for those using the board? It's a DIY project, that I had an order of manufactured because I didn't want to be bothered soldering my own, and I asked if anyone else wnted some too - this is not a commercial project and I'm making no money on it. All the necessary documentation is in Leo's download file. There's no 'documentation' because the wiring is obvious from the schematic. I did also think I'd answered your questions last night by email - this is a hobby for me too, not a job, and I am on a business trip answering people questions from my laptop in a hotel room.I wouldn't say "No knows how to connect it", either - I'm not an electronics expert by any stretch of the imagination, and I had no problem figuring it out from the schematic and the PCB. "Which of the power plug pins is the ground?" Hint...... look at the back of the board. See the wide copper trace that goes all the way round the outside, that all the mounting screw holes go through? Guess what - that's the ground. See that one of the two pins on the power plug is connected to that thick copper trace? Guess what - that's the ground pin.

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>#1 I'm not sure which is the ground on the power input of the > > decoder.It's the pin closest to JP7 on the decoder>>#2 I understand that the decoder can accommodate 3 encoders.>This > makes sense since there are 3 banks of 4 pins (JP1, JP2,>JP3) and > 3 banks of 3 pins (JP5, JP6, JP7). I'm guessing that they>are the > inputs and outputs of the decoder. But which is which?JP5,6,7 are INPUTS; JP1,2,3 are OUTPUTs>>#3 How do I connect a rotary encoder to the decoder (more > precisely, how do I connect all 3?). The rotary encoder has>3 > outputs but where do they go?INPUTS: Connect Center pin of rotary 1 to center pin (2) of JP4. Connect the outside pins of the rotary to the outside pins (1 & 3) of JP4. (If you can determine which of your rotary pins is "A" then connect that to pin 1)OUTPUTS: Connect pin 1 or 2 (the rightmost pins) of JP1 to a Photon Input pin and map it to an INCREMENT function. Connect pin 3 or 4 (the leftmost pins) of JP1 to a Photon Input pin and map it to a DECREMENT function. >>#4 The output of the decoder to the input of the photon I'm>assuming > carries one ground with the remaining connecting as a>normal > switch?NO - all 4 pins are data outputs (pin 1=A, pin2=A, pin3=B, pin4=:(. Common ground is obtained by using the Photon input module to power the decoder.Hopefully this will clear things up!Regards,ScottScott L. Fausel, VMDIntegrated Flight Systemshttp://www.iflightsystems.com

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Well, my first solution was premature. I can get an indication of output going LO from my logic probe from any pin but my previous suggestions do not work with Photon.It may be a polling issue (the new decoder is based upon a faster polling rate) or a question of grounding the right pin.Working on possible solutions - please be patient - thanks!-Scott

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Okay, looks like the following amendment should finalize things:For OUTPUT jumpers, pins 1 and 3 are "A" and "B" outputs that you connect to Photon Input Module ports while pins 2 & 4 are connected to GND.Tested and working fine with Photon.Sorry for contributing to the confusion! Hopefully this will do it!-Scott

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Anyone know a source for Quadrature (phase coded) relative encoders with push button switch. I was informed those are rotary encoders needed to connect to the decoder board. Apparently my CTS 2-bit gray rotaries will not work.I have had no luck at Mouser, Newark, and Grayhill. Digi-key has a cheap one but without switch. Thanks,Richard

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Just to clarify, the push button switch feature is only needed by me for the Airbus FCU. Push button is not required for the decoder board.Richard

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The logic of 2-bit gray IS phase encoded. Your CTS should work with the decoder but depending on models, every 2nd detent will result in a pulse. Do you have a link to spec sheets I can take a look?-Leo

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Hi Leo,I'll ask Scott to forward you the .pdf file. Richard

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Richard,I just looked through the pdf file and the RTS you specified are not 2-bit gray, they come in either 2-bit binary or 4-bit gray and neither is compatible with my decoder.These require completely different logic to decode. From what I can tell you will only get 1 pulse every 4th detent using my decoder.Unfortunately I have not been able to find compatible 2-bit gray code rotaries with the integrated switch like the RTS you have.-Leo

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Thanks for looking at the data sheet Leo.That is disturbing news. The Airbus FCU and EFIS requires push-pull switching along with the rotaty. I built six holders specifically for those rotaries. The second "pull" switch was added by using a snap switch. The setup works perfectly and I was looking forward to the rotary for changing display readouts. Not sure what to do now. I suppose I'll keep hunting for a replacement rotary.Again, thanks for the help,RichardP.S. I don't remember reading anything about the type of rotary needed for the Pan16. I never thought to ask if mine were compatible. In case anyone else is have poblems, you might want to verify your rotaty encoders are compatible.

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Richard, are you using the Photon? Do you get some indications that a pulse is being dectected allbeit sporadic?I'm having problems despite all being connected correctly. I emailed Peter Cos of FDS asking what type of rotaries I have (using their push-pulls) and was told they are 'standard' units. I've been searching the web to order some rotaries myself to test different types but I'm having difficulty finding any!This is really getting frustrating :-)Best wishes,Darren

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Hi Darren,Yes, I'm using the Photon. I do get sporatic display changes, but mostly nothing. I can see the red test light sometimes, but again mostly nothing. Last night, both the altimeter AND altitude were making sporatic changes even though only the altimeter was mapped. I looked at Pete's site. I'm guessing, but I would think he sells rotaries that just support the interfaceIT. You must have purchased his rotary holders for the Airbus? You probably have the same type encoders as I do. I purchased mine from AGT/Aircraft Simulators.I'm still researching. I may have found a possible sub at Mouser. It's a Bourns 12mm 2-bit gray quadrature output and switch. Not sure if it will fit my holder.I'm a bit disappointed with this issue also. As I wrote earlier, I don't recall ever reading anything about the type of rotary needed. If I had, I probably would not have purchased the Pan16 decoders. I'll keep looking and post if I see any rotaries that might work.Richard

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Thanks, Richard.I'm getting the same results as you with the Photon. Well at least I now know the probable cause - incompatible rotary with the decoder. I must admit, I didn't think there were different types of rotaries.I would be grateful if you would keep me posted if you do find a rotary that works. but then there will be the wuestion of I can fit to to FDS's push pulls! :(darren@sugden.karoo.co.ukBest wishes,Darren

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