A few questions about encoders

[Nate]

I've been lurking around for a while trying to learn as much as I can, but I have a few questions. I would like to integrate a jog wheel into my project, but I'm not sure what route to go. I think I would like to implement a rotary optical encoder along the lines of what rasteri developed. This seems like it would yield the highest performance at the lowest cost.

How exactly does an optical encoder integrate into the various modules? Is it "plug and play" so to speak, or will I have to code a program to interpret the signal? I have ordered a core32, DIN, DOUT, and AIN module to play around with to help me understand their workings before I tackle my first project. Any insight regarding optical (or any) rotary encoders would be very helpful.

thanks,

nate

[lylehaze]

I've been lurking around for a while trying to learn as much as I can, but I have a few questions. I would like to integrate a jog wheel into my project, but I'm not sure what route to go. I think I would like to implement a rotary optical encoder along the lines of what rasteri developed. This seems like it would yield the highest performance at the lowest cost.

How exactly does an optical encoder integrate into the various modules? Is it "plug and play" so to speak, or will I have to code a program to interpret the signal? I have ordered a core32, DIN, DOUT, and AIN module to play around with to help me understand their workings before I tackle my first project. Any insight regarding optical (or any) rotary encoders would be very helpful.

thanks,

nate

The Wiki has a good paragraph about the difference between pots and encoders.

http://www.midibox.org/dokuwiki/doku.php?id=questions_and_answers

Just look for "What's the difference between potentiometers, sliders, motor faders and encoders?"

MIOS handles all the ugly details of reading the encoders for you. You might want to read the MIOS_ENC section at

http://www.ucapps.de/mios_fun.html

Or if you just want to react whenever the jog wheel is turned, you would write a function called "USER_ENC_NotifyChange"

that will be called by MIOS every time an encoder moves. You'll find details on that in the function list too.

Each encoder will need two DIN's to connect to MIOS.. SO a DINX4 which has 32 inputs could support up to 16 encoders. If your jog wheel will get a lot of usage, or if you want an especially high resolution, you might consider an optical instead of a mechanical type. I paid about $25 US for mine, and it will probably outlive me.

Have Fun,

LyleHaze

[Nate]

Wow, thanks very much LyleHaze... very helpful. Would you mind telling me what model encoder you purchased? how many signals/revolution? how does it perform (in your opinion). I personally like the idea of hacking into an old mouse and snagging the photosensors... that way I can "tune" the resolution to my liking.

Thanks again, nate

[lylehaze]

Wow, thanks very much LyleHaze... very helpful. Would you mind telling me what model encoder you purchased? how many signals/revolution? how does it perform (in your opinion). I personally like the idea of hacking into an old mouse and snagging the photosensors... that way I can "tune" the resolution to my liking.

Thanks again, nate

I don't recall the details.. I ended up buying two.. the first was just too high res, it seemed like too much change per revolution.

That can be controlled somewhat in software, but I went a bit too far..

I do remember buying it from Digi-Key, and I know it was an optical type with a pushbutton.

On the MBMIxer I have only ONE control.. and this is it. Push to change channels, turn to set volume, Push and turn to set Balance..

Of course it's designed to be controlled remotely. I only wanted the bare-minimum local control on the mixer itself.

Using mouse-guts is a cheap way to get an encoder, but how "repeatable" is the linkage? Especially for a jog wheel or scratch wheel, I would think that a direct linkage would give a more solid feel.. But hey, this is all about trying different things.

An inexpensive mechanical encoder can give you a solid start until you get your core and software in place and tested.. then you can try homemade "Mouse Guts" type or decide to spend $20 for a hi-res optical unit... it's all about your own choices.

Have Fun,

LyleHaze