Looking for Dual Rotary Encoders

[rfresh737]

I'm building a G1000 panel and am looking to buy some dual rotary encoders. The right kind (specification) seems to be hard to find.

I need the following and was wondering what anyone else has been able to find?

1. Dual rotary encoder.
2. Detents on both shafts. Can be 16 or 18 or 20 detents, etc. I'm not too specific on this requirement.
3. Inner shaft has push in toggle switch feature.
4. I'm not specific as to how detents but I need the PPR to match the number of detents.

I purchased a dual rotary encoder from Leo Bodnar (expensive) but when I connected it to my Ardunio board, it only fired on every 2nd turn. I need it to fire on each detent click. I believe this (the Leo encoder) kind of setup is spec'd something like this: 30 detents/15 PPR. I could be wrong here. Anyway, I need an encoder to fire (the A pin) on every detent turn so my code can detect that event and then respond accordingly. I think the spec for something like that would look like this: 18 detents/18 PPR.

I have found some dual rotary encoders but without push in switch feature. For the G1000 I need push in switch capability.

Thanks for any help.

[RayS]

You should try a Teensy board.. the encoder library is a bit more mature.

I had the same problem as you. Check your Arduino code... there's probably a "divide" command somewhere that you'll need to change. I had one in my code that was dividing events by 4. I changed it to 2 and that fixed the issue.

[KyleH]

Grayhill 62C2222-02-100S is a dual encoder and has a push button on it as well.
Alps also has a model, don't remember the part number.


EDIT:
Alps EC11 series:
http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC11/EC11_list.html
I think this is the part:
http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC11/EC11EBB24C03.html

[rfresh737]

You should try a Teensy board.. the encoder library is a bit more mature.

I had the same problem as you. Check your Arduino code... there's probably a "divide" command somewhere that you'll need to change. I had one in my code that was dividing events by 4. I changed it to 2 and that fixed the issue.

Hi Ray,

I have many Teensy boards (4 LCs and 4 of their latest 3.2) and with my breadboard prototyping I have many encoders of different types, all working fine. The Teensy, in my opinion, has the finest libraries of them all, including the Ardunio (of which I have *many* of their boards). So, yes, I agree 100%, the Teensy encoder library is excellent.

The problem is the specs the encoders were manufactured with. People think encoders are pretty much all the same but they are very different internally. Most of the single shaft encoders have matching PPR/Detents and that's what I need. I'm not aware of any way to change them using software, so if you have some code that does that, I'd be very glad to learn something new about encoders! You may have the solution because my Leo Bodnar encoders don't have matching PPRs/Detents but if I can change that in software, then problem solved!

Almost all of the dual shaft encoders I've seen (their spec sheets) do not have matching PPRs/Detents including the ones from Leo Bodnar which are expensive. The G1000 doesn't use any dual shaft encoders with PPRs that are 50% of their rated detent numbers. Their dual shaft encoders must have matching PPRs/Detents.

I'm finding it very difficult to find a dual shaft encoder with matching PPR/Detents such that with each click, the A pin fires. I don't need to detect both the A and B pins firing, the A pin is enough. All I need to do is determine which way the knob is being turned.

[rfresh737]

Grayhill 62C2222-02-100S is a dual encoder and has a push button on it as well.
Alps also has a model, don't remember the part number.


EDIT:
Alps EC11 series:
http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC11/EC11_list.html
I think this is the part:
http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC11/EC11EBB24C03.html

Hi Kyle,

I've looked at those in detail but unfortunately, they are 15 PPRs and 30 Detents which means you need to turn the knob two clicks to get a Pin A fire event.

But thank you for trying to help me.

[mickc]

I might be missing something here, but if you are only using Pin A, then you will always have the problem with the pulses per detent ratio. 
The quoted ratio in spec sheets will assume you are using pins A&B

Also to establish the direction of the encoder, you need to use pin A and B, as it is the timing between them that allows the controller to establish the direction of rotation.

[mickc]

Also the Elma E37 does come in a 16 Detent / 16 Pulse version

Part number is E37-VT6650-1  as per the last page on the attached datasheet

[rfresh737]

I might be missing something here, but if you are only using Pin A, then you will always have the problem with the pulses per detent ratio. 
The quoted ratio in spec sheets will assume you are using pins A&B

Also to establish the direction of the encoder, you need to use pin A and B, as it is the timing between them that allows the controller to establish the direction of rotation.

Hi Mick,

You are absolutely correct. I omitted mentioning the B pin because in my code, I fire the event on the A Pin falling and THEN I check to see where the B Pin is, to determine knob turn direction. Sorry for the confusion, I should have said that from the beginning. So, yes, I am checking both the A and B Pins.

[rfresh737]

Also the Elma E37 does come in a 16 Detent / 16 Pulse version

Part number is E37-VT6650-1  as per the last page on the attached datasheet

Hi Mick,

Ah ha! You're right. That data sheet shows that a 16/16 (PPR/Detent) encoder is available with a push-in switch feature! I will see where I can buy one of those and try it out before ordering more for my G1000 panel. Many thanks for the help!

[KyleH]

Can you not fix your code to check both A and B for a change, then determine which direction it is turning?
It'll open up a lot more options for you rather than buying a part that fits how it's been coded.

[rfresh737]

Can you not fix your code to check both A and B for a change, then determine which direction it is turning?
It'll open up a lot more options for you rather than buying a part that fits how it's been coded.

Hi Kyle,

Yes, that's how I do it. In my code I check both the A and B Pins. However, we don't control when the pulse fires in the encoder itself which we can then determine in our code exactly when to check the A and B pins. When the pulse fires from the encoder is the key to these dual shaft encoders.

My single shaft encoders all generate a pulse on every detent as we want. The Leo Bodnar dual shaft encoder doesn't generate a pulse on every click, it generates one on every other click (which won't work for most of us).

I emailed the Elma 37 spec sheet to Leo Bodnar and asked if they had the 16/16 encoder and they said "we only sell what you see on our website". I said your website doesn't indicate what the spec is for the encoder your selling...so one is buying 'blind' which is what happened to me.

I've discovered trying to buy a dual shaft encoder without specifying a spec for it is like buying a car with specifying the options you want. You won't know what you'll get until you actually see it.

www.don-audio.com has the Elma 37 and the knobs for it. I'm in the process of confirming with them that I can buy the 16/16 spec encoder.