Rotary Encoder question...

[tomzarbo]

So, I've asked questions about rotary encoders before here. I am old school and I just love to turn an old-fashioned knob to get my volume up and down.

I came across this product on another site and it looks like it MAY have a hook-up for adding a rotary encoder on it, (see red arrow in lower pic)
I'd love to give this a try, but most rotary encoders I see have at least 5 leads on them, some more.



What do you guys think about this? I'd be willing to pick one up and give it a try taking your suggestions on how to wire it if there's any chance it would work.

I would LOVE to have a big, fat knob to turn up the volume on future table radio and boombox projects, I think it would add a nice touch of class to any radio project.

Thanks for any ideas,

TomZ

[Billet]

It could be for a mechanical encoder, they can work with three pins. A mechanical encoder is basically two switches that are actuated in a sequence for clockwise or counterclockwise rotation.

[silverD]

Yep, it looks to me like you could use an encoder there. The reason some encoders have 5 pins (instead of 3) is that they have a push button switch integrated into them. The center pin will typically be ground and the outer pins are data. I'm not sure if this device has a debounce circuit integrated into it or not, but it will be obvious if the encoder has erratic operation once connected.

[silverD]

Here is an encoder with a debouce circuit typically used with 5 volt logic I/O pins.

[tomzarbo]

Okay guys, thanks for the responses.

It looks like someone designed this thing to have decent adjustability and implementation options with the 5v and 12v inputs, rotary encoder pins, etc. I've never seen one of these boards with that feature, and I've looked at dozens and dozens of them.

I do remember reading about the debounce issue last time I brought the topic up.

I'm going to pick one or two of these things up and see what they're made of. The other popular one that PE sells with the slightly more sculpted plastic face hasn't worked well for me, I may have gotten a few duds though. The sound quality on that one was fine for radios and such, but I've had a few quit working on me after a while.

To test the three pins on the board, I'd connect the center and left pin for volume down, center and right for volume up? Come to think of it, I'm not sure the encoder would even control the volume by default, though it would make sense to.

Anyway, once I get one home, I'll give it a run and play with it a bit.

Thanks again for helping me out with some ideas, guys.

TomZ

[Dukk]

That is a neat looking piece TomZ. Do keep us updated on if it is any good please.

[silverD]

Hi Tom,
Yep, I do think that would work for testing. Make sure they are momentary connections. I assume these aren't too expensive and you won't be upset if your testing causes failure. Have you found a manual for them?

[Billet]

For testing, you would be far better off with an actual encoder. Encoders send a repeating pattern of four states and determine direction by the order of the states. Not impossible with two switches, but not easy either.

[silverD]

For testing, you would be far better off with an actual encoder. Encoders send a repeating pattern of four states and determine direction by the order of the states. Not impossible with two switches, but not easy either.

Agreed. I used the Adafruit encoder and the debounce circuit above (3.3V) for my recent amp.

[tomzarbo]

So I should probably use an encoder to test with, gotcha. I may play with one with just the wires if my patience gives out.

I didn't look for a manual, but they usually just post some data online and you make a few guesses. I won't mind if I fry one, I'll order two in case I do.

This thing will take a few weeks to come on the slow boat from China, so I'll have time to choose an encoder to use with it.

I'll post any results I come up with.

TomZ

[devnull]

Okay guys, thanks for the responses.

It looks like someone designed this thing to have decent adjustability and implementation options with the 5v and 12v inputs, rotary encoder pins, etc. I've never seen one of these boards with that feature, and I've looked at dozens and dozens of them.

I do remember reading about the debounce issue last time I brought the topic up.

I'm going to pick one or two of these things up and see what they're made of. The other popular one that PE sells with the slightly more sculpted plastic face hasn't worked well for me, I may have gotten a few duds though. The sound quality on that one was fine for radios and such, but I've had a few quit working on me after a while.

To test the three pins on the board, I'd connect the center and left pin for volume down, center and right for volume up? Come to think of it, I'm not sure the encoder would even control the volume by default, though it would make sense to.

Anyway, once I get one home, I'll give it a run and play with it a bit.

Thanks again for helping me out with some ideas, guys.

TomZ

You should check the pins on the board. They should have been labeled. One of the pins should either be ground or Vcc.

[tomzarbo]

I haven't seen any markings on the pics I've seen, maybe once I get it in person I will see something else or be able to sort it out better.

TomZ

[tomzarbo]

Got this in earlier than expected.
Left tab is square, the other two are circles...
would I assume the square is ground... and which lines should I touch to make the volume go up/ down?


TomZ

[tomzarbo]

Sorry, that pic is still a touch blurry, but there are no markings on it.
TomZ

[Billet]

I think the square pad usually indicates pin1. If I remember correctly, the center pin of a three line mechanical encoder is the common.