32
outputs MIDI Decoder
Here
is the description a 32 outputs MIDI able
to switch relays, electromagnetics
devices... in order to automate a
mechanical musical instrument, or command
lights...
Principle
and Schématic
MIDI
datas from a musical instrument equipped
with an MIDI output or from a sound card
of a computer
are analyzed by the software present on
the PIV 16F84.
Optocouplor
IC10 (1N136) ensures the galvanic
insulation.
The outputs of PortB form a 8 bits
parallel bus data towards the four
74LS574 (8 Latches),
the outputs of PortA 1,2,3,4 order the
memorizing of these 74LS574
Buffers ULN2803 make it possible to
control loads until 2 A .
The power supply 5V is articulated around
a regulator 7805.
Connector CN7 receives the power supply
from 9 to 24v according to the type of
relay or electromagnet.
while
clicking on the diagram you reach the
shéma in large size.
this diagram is made with ExpressPCB ,
(Freeware)
Components list
R1 220 Ohms 1/4W
R2 3,3K 1/4W
R3, R4 1 K 1/4W
R5 470 Ohms 1/4W
R6 ... R9 10 K 1/4W
SIL1 ...SILl4 1K R-sil-09
C1 1000 Radial uF 40V
C2, Radial C3 10 uf 16V
C4 ...C9 100 nF 63V
C10, C11 33 PF 63V
Q1 Quartz 8 MCHz HC18U
LD1 ...LD32 LED red D3
LD32, green LD33 LED D3
D1 1N4148
P1 Pont W04
Transformer TR1 230V/2X6V 3VA or
1X12V 3VA
F1 Support of fuse and fusible
200mA
CN1 ...CN4 connector block 8
points with screw
CN5 DIN 5Br frame 45°
CN6, CN7 connector block 2 points
with screw
REG 7805
IC1 16F8Â
IC2... IC5 74LS574
IC6... IC 9 ULN280Á
IC10 Ñ136 |
Realization
For
a facility of realization the printed
circuit is a simple face with some
straps.
I
use LAYO1 (the
version of demonstration is free). here
the file with the Layo1 format: decomidi.pcb
and
GIF: ci_decomidi.gif
Wiring
The
output from 1 to 32 correspond to the G
low (1) and D high (32).
the relay or electromagnetic device is
wired between one of these outputs and
the +12V of auxiliary power
Be carefull !! dont
forget to wire the four 10 K resistors
(R6 to R9) on the back
of the printed board (pin 11 of each
74LS74 and +5V)
Software
the
sofware, made in assembler for PIC
16F84A, was developed with MPLAB of
Microchip .
It is downloadable in format
ASM
or
HEX
for
direct programming of the PEAK (with
Ic-prog for example)
and a programmer: C.Tavernier
The
data arrive on PortA.0 which is scanned
permanently.
Dice that the code Notes ONE on channel 1
(90) is detected the program analyzes the
MIDI code N° 2 which corresponds to the
height of the note (69 is equal to the
440Hz) and valid the corresponding output
The MIDI code N°3 (dynamics) is not
used.
If
a code MIDI Notes OFF (80) the output
goes down
it is possible to play until 10 notes at
the same time.
At
the power up fours notes are actived for
a short moment (C,E,G,C)
Tessiture
and Test
of the notes (useful
file MIDI to test the chart)
a very complete
program to create and publish partitions,
to modify files MIDI:
Melody Assistant 
Contact
E-mail:
contact@victorseraphine.com
|
Présentation... 
