USB MIDI controller with rotary encoders

[joselinno]

Hi all, first post!

First of all sorry for my english...
Well I'm planning to build a MIDI Controller, It would send CCs to Ableton and Reaper to control VSTs.
I would like to use Teensy LC.
The controller will have 8 knobs and 1 100mm fader.
Fader will be analog (I don't want a motorized thing, don't need that) but I would like to use encoders (non-detented) instead of analog pots, like the ones on this thing:



Which type of rotary encoder do I need? How many PPR? Absolute or incremental?

I know fader should be linear but, what value should I use? 10k would do the trick?

It's hard to write the code for this thing? I have built some analog electronic stuff before but I'm totally noob with digital...

Thanks

 

[Gerrit]

Hi all, first post!

First of all sorry for my english...
Well I'm planning to build a MIDI Controller, It would send CCs to Ableton and Reaper to control VSTs.
I would like to use Teensy LC.
The controller will have 8 knobs and 1 100mm fader.
Fader will be analog (I don't want a motorized thing, don't need that) but I would like to use encoders (non-detented) instead of analog pots, like the ones on this thing:

View attachment 14497

Which type of rotary encoder do I need? How many PPR? Absolute or incremental?

I know fader should be linear but, what value should I use? 10k would do the trick?

It's hard to write the code for this thing? I have built some analog electronic stuff before but I'm totally noob with digital...

Thanks

Typical you'd use an incremental rotary encoder. How many PPR is up to you and how the DAW responds to the encoder. Mechanical (inexpensive) encoders go up to 24 PPR (96 ticks after quadrature decoding). Depending on the budget you might want to use optical encoders, these can have higher resolution and do not need to be debounced. For my project I used optical encoders with 64PPR, these can cover the standard midi range with a single turn.

10k lin is a good (standard) value for the fader.

There are examples in the Teensyduino install, look under File > Examples > Teensy > USB_MIDI and see if you can understand what's going on. For rotary encoders there's the encoder library. Keep in mind that this library does not debounce the encoder.

 

[joselinno]

Thanks for the reply.
"debounce" = translating pulses from encoder to MIDI CC values (0-127) ??? Is that done with lines of code?

 

[Gerrit]

Thanks for the reply.
"debounce" = translating pulses from encoder to MIDI CC values (0-127) ??? Is that done with lines of code?

No, debouncing has to do with the way mechanical switches work. The contacts of mechanical switches literally bounce, in stead of a single switch action there're several actions in a very short time (see Bounce). Debouncing mechanical encoders can be done in hardware, see the suggested filter circuit in the Bourns datasheet, or in software. Debouncing in software is easier, here's an example: Encoders (once more).

If you're just getting started all of this can be a bit overwhelming, just take the time to grasp the fundamentals, try to understand the code in the examples, think what it is you want the controller to do and take it from there.

 

[joselinno]

If you're just getting started all of this can be a bit overwhelming, just take the time to grasp the fundamentals, try to understand the code in the examples, think what it is you want the controller to do and take it from there.

Yes, overwhelming is the word XD...
I'm reading the basic tutorials ATM.
Thanks for your answers