Skip to content
View in the app

A better way to browse. Learn more.

The AVSIM Community

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Help needed connecting rotary decoder (to photon)

Featured Replies

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

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

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

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

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

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

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

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

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

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

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

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

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.

>#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

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

Create an account or sign in to comment

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.