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Spider RooM Labs


MIDI to Sync24 converter with shuffle

Project is in beta stage

This project was initiated by Dan Gendreau which give the original idea which I transformed into code. I found the project interesting because it was quite challenging to pull out the whole thing with only one 8-bit timer that exists on the PIC16F84 (it served for both MIDI bit timing and MIDI tick period measuring).


After almost two years since I last touched this project I've started debugging it again and now I came up with working beta version for both PIC16F84 and PIC16F628. I've also changed circuit a bit (added pull-down resistors on encoder's inputs). Note that both supported micros use the same circuit and also have identical features.

Features (version 0.97b - beta version):

 - 24 ppqn sync output
 - normal (non-shuffling) mode and 11 shuffle modes selectable via rotary switch
 - four different time signature modes (2/4, 3/4, 4/4, and 4/3) selectable via rotary switch
 - Roland type Start/Stop and Continue outputs
 - Sync24 DIN socket
 - works from 20 BPM up to 300 BPM
 - optional MIDI Thru socket and MIDI activity LED

Known problems:

I have to improve the shuffle intensity limiting, since current code can cause problems (skip clocks or even lock up) at very high intensity levels and very fast tempo (over 300BPM).

Schematic, PCB layout, partlist (final)

Source and program code (please pick the right one for your selected PIC):

Source and program code (PIC16F628 v0.97b - beta version)

Source and program code (PIC16F84 v0.97b - beta version)

(C) 1999-2000 Bojan Burkeljc
Last update: 24th August 2002