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2018/12/21 23:47
SEQv4+ le mec
This board holds the SEQ's illuminated buttons, which are driven from a shift register matrix. The
PLATE
board stacks on top.
Schematic
A shift register chain of 3 DIN 74HC165 and 2 DOUT 74HC595 chips are used. Two of the DINs scan
the encoders and one scans the button columns. The DOUT parts are connected into a matrix. Note
that both the high and low sides have driver transistors (PNP and NPN, respectively). This means that
the anode side of the matrix will operate with inverted behaviour (pin high = LED off). Actually the low
(cathode) side is also "inverted," as we turn the transistor "on" to sink the current by toggling the 595
pin high.
There are special instructions for connecting the parts which are covered below.
BOM v1.0
Please find the current BOM on http://midiphy.com. The table below is depreciated and
will not be updated.
Type Qty Value
1
wire link
16 47R 5%
100-220R
10
5%
16 1k 5%
8
10k 5%
3
9*10k
5
100n
do not fit
0
24 1N4148
24 BAT54
MIDIbox - http://www.midibox.org/dokuwiki/
Package
Parts
THT
R17
THT
RJ1-8
THT or
SJ1-8,
1206
RJ9
THT
R1-16
1206
R18-25
Resistor networks
SIP10
RN1-3
1206
C1-5
C6
THT
SOT-23
512-BAT54
1/6
Mouser
Reichelt Conrad Other
Resistors
Capacitors
Diodes
BAT 54
SMD
SEQv4+ le mec
ENC-
Notes
see
instructions
see
instructions
near NPN
bussed
network,
not 5 pairs
of resistors
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Related Manuals for MIDIbox SEQv4+ le mec
Summary of Contents for MIDIbox SEQv4+ le mec
- Page 1 2018/12/21 23:47 SEQv4+ le mec SEQv4+ le mec This board holds the SEQ's illuminated buttons, which are driven from a shift register matrix. The ENC- PLATE board stacks on top. Schematic A shift register chain of 3 DIN 74HC165 and 2 DOUT 74HC595 chips are used. Two of the DINs scan the encoders and one scans the button columns.
- Page 2 Last update: 2018/12/18 09:35 seqv4plus_le_mec http://www.midibox.org/dokuwiki/doku.php?id=seqv4plus_le_mec Type Qty Value Package Parts Mouser Reichelt Conrad Other Notes Resistors ELV: 16 RGB flat superflux 68-10 instructions 94 64 insert into various switches Transistors BC808 SO-23 BC818 SO-23 IC1, IC3, 74HC165 SOIC16 595-SN74HC165DR...
- Page 3 2018/12/21 23:47 SEQv4+ le mec Ghosting. As seems common with these kinds of matrices, there is some unwanted lighting of LEDs. This is most apparent when trying to light up the bottom row of MEC switch LEDs, as the resistive path to the Superflux LED is lower and thus glows unintentionally.
- Page 4 It's very important to have the pin 1 dot aligned with the silkscreen marking. The LEDs are available in RGB, but the official MIDIbox SEQ software only supports two of these colours. (if wanted, you could attach 0.1“ headers to the PCB and drive the LEDs with custom hardware.) So we need to select what LEDs are in the matrix using the resistor jumpers (RJ).
- Page 5 2018/12/21 23:47 SEQv4+ le mec SJs are similar. As the current is quite high to drive the RGB LEDs, it's wise to use a 100-220R resistor to provide suitable current to the MEC LEDs. The position should match 1, 2 or 3 (two arbitrary positions) according to how the RJ of the same column is connected.
- Page 6 Last update: 2018/12/18 09:35 seqv4plus_le_mec http://www.midibox.org/dokuwiki/doku.php?id=seqv4plus_le_mec License Currently the design is © 2017 antilog devices with all rights reserved; all documentation is CC BY- NC-SA 3.0. From: http://www.midibox.org/dokuwiki/ - MIDIbox Permanent link: http://www.midibox.org/dokuwiki/doku.php?id=seqv4plus_le_mec Last update: 2018/12/18 09:35 http://www.midibox.org/dokuwiki/ Printed on 2018/12/21 23:47...
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