www.96kHz.org
advanced audio recording
Digital MIDI controller
  15
endless
rotary
encoders

1
virtual
input
channel

10 bits
accuracy

1024
steps
resolution

acceleration
option

fine
tuning
option

A 16 channel digital MIDI controller

DIY MIDI Contoller


15 rotary encoders of ALPS with pushbuttons are included in the box. A Xilinx FPGA (formerly PLD) is used to interpret the movement information and send it via 230kbps serial interface to the computer or the DIY audio workstation. The controller data has always 10 bits for 1024 step fine resolution either achieved by 1,2,4 or 8 complete turns of the controller (programmable). Intelligent acceleration is used as well as fine adjustment when pressing the knobs.

A virtual channel for pass through is added on MIDI channel 0.


A FPGA ist used to control the data streams:

MIDI Controller with virtual input and 10 bit
 The FPGA can operate the incoming data much quicker if required, but a 750 point per second resolution obtained from the sequential polling seems sufficiant. If desired the transmission speed could be increased up to 920kbaud, but 230kbaud is the limit of most simple UARTs with PCs.
See the data protocol options of my improved MIDI for details.

Standard CTRL setup for Synth Control:

DIY MIDI Contoller

A next step is to implement the MIDI over S/PDIF for fast transmission and adaption to the workstation.


Screenshot of DIY MIDI Contoller VGA Screen
 ScreenShot of the MIDI Controller GUI from Cinema 4D.


Screenshot of DIY MIDI Contoller VGA Screen
 ScreenShot of the MIDI Controller GUI with digital values.

See another Version of the MIDI Controller 15


 

 

© Jürgen Schuhmacher 2005