DINer
MIDI to Sync24 converter
Features (version 2.31 - final version):
- 9 tempo outputs: 48 ppqn (see shout
out below), 24 ppqn, 8 ppqn, 4 ppqn, 2 ppqn,
1 ppqn, 2 ppwn, 1 ppwn, 0.5 ppwn
- Roland type Start/Stop and Continue
outputs
- Sync24 DIN socket
- works up to 360 BPM (tested with
Roland TR-606) ;->
- optional MIDI Thru socket and MIDI
activity LED
PCB - component
side
PCB - solder
side
Program, source, and
some additional text files (version 2.31)
Part list:
Resistors (1/4W carbon or metal film):
1x 220R
1x 360R
2x 220R (optional)
1x 1k2 (optional)
Capacitors:
2x 22pF ceramic
1x 10nF ceramic multilayer
2x 47uF/25V electrolytic
Diodes:
5x 1N4148
1x LED of your choice (optional)
ICs:
1x PIC16F84
1x 6N137
1x 78L05
1x 74HC14 (optional)
Other:
1x 4MHz cristal/resonator
1x 18pin DIP socket
1x 14pin DIP socket (optional)
1x 8pin DIP socket
3x DIN 5pin connectors
10x 1/4" or 1/8" jacks
1x connector for power supply of your choice
1x PCB (or protoboard)
1x case to put everything in
1x Power supply (up to 18V DC or 12V AC)
Circuit description:
This is pretty much straight
forward. MIDI input is separated
from the rest of the circuit by an optocoupler.
The signal from the
opto is then passed to PIC and - optionally
- to 7414 hex Schmitt
inverter, which drives MIDI Thru and activity
LED.
From the PIC, the 24 ppqn tempo, Start/Stop,
and Continue lines are
connected to the DIN Sync socket. All the
lines go to PCB connectors
which can be fitted with 1/4" or 1/8" connectors
on the front panel.
PIC program description:
Since the PICF8x lacks
the UART, it must always run in 32us loop
to read MIDI line properly (1/32us = 31250
baud); at 4MHz cristal that
means looping on 32 machine clocks. First
it has to synchronize into MIDI
stream, so that it does not cause any misreading
and faulty commands.
Second part of the program is the main loop
in which PIC checks for MIDI
bytes, filters out anything unwanted, and
makes appropriate changes to
output pins.
Using the device:
DIN sync converter is used
to sync some of pre-MIDI drum machines
and sequencers (e.g. all those X0X Roland
boxes) to MIDI. Additional
output jacks are used for synchronizing other
devices (e.g. analog
sequencers).
Connect device to MIDI
and to device you want to synchronize
using either DIN Sync or jack outputs and
start your MIDI sequencer.
Note that 24 and 48 ppqn
lines are running all the time (if there
are incoming tick messages, of course), while
other lines will start
running on Start message and end running
on Stop message.