www.96kHz.org
advanced audio recording
DIY MIDI controller with fast IO
  endless
rotary
encoders

10 bits
accuracy
passible

1024
steps
resolution
at least

speed
acceleration
and fine
tuning
option

fine tuning
by pushing
buttons

optical
overlay of
scaling and
value

high speed
transmission
interface
VSPDIF

1024 step MIDI controller
.
DIY MIDI Contoller with optical feedback - 2012

Several of this rotary encoders with push buttons will be assembled in a MIDI-box, offering both direct feedback of the controller value and resulting effect in the controlled device. The box is covered by an acryl plate.

DIY MIDI Contoller with optical feedback - 2012


Interpretation of the AB-information of the rotary encoders and push buttons is either done by an Altera FPGA or a micro controller unit. Data shall be send by SPI @ 10 MHz serial connection or using enhanced MIDI. The controller data will have a resolution of 10 bits offering 1024 steps. Intelligent acceleration will be used as well as precision adjustment when pushing the buttons. The intention is to easily and securly increase any value by just 1 step without unwanted jumps and achieve the full range by some turns though. Linear and logarithmic output is possible.


DIY Music MIDI Contoller with optical feedback -1024 step rotary encoder application
At first step a 8x2 matrix is implemented:




Scaling of stereo base with a virtual LED feedback

 This exampe shows the dynamic and flexible scaling to represent the data. Implicit and explicit scale dividers can be used by "plotting" them in a different LED colour or leave them away by grouping LEDs. See the "blance 3.5" for an example. The colours can also be used to represent values which in the other case would exceed the range. As soon as grenn is fully used, the colour changes to yellow just as if it was an overlay.


See this Realization in Youtube: MIDI Contoller Animation



Follow the discussion on the german UCNET: Universal Contoller


Rotary Encoders used in the device:

Scaling of stereo base with a virtual LED feedback


Realization Example: 4x2 Matrix with 8 pieces:

High Resolution MIDI Controller with optical feedback - spartan 6 FPGA


Application Example: FPGA based Audio DSP


Virtual Waldorf Microwave MIDI Controller Application

A virtual console is used to set and represent the controller values. In this case, the VA-Synthesizer is controlled to behave as a vintage Waldorf Microwave XT Synthesizer. Read more about on the project page: Virtual Waldorf Microwave.


More Information:


Planning Resource: Colours and Timing of the electronics



Read about another Controller: 15 channel MIDI controller with high speed transmission


Read about the enhanced MIDI protocol using S/PDIF: Serial high speed MIDI


 

 

© Jürgen Schuhmacher 2012