MIDIbox SEQv4+ le mec, Manual

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2018/12/21 23:47 1/6 SEQv4+ le mec
MIDIbox - http://www.midibox.org/dokuwiki/
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. 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 Package Parts Mouser Reichelt Conrad Other Notes
Resistors
1 wire link THT R17
16 47R 5% THT RJ1-8
see
instructions
10
100-220R
5% THT or
1206 SJ1-8,
RJ9 see
instructions
16 1k 5% THT R1-16
8 10k 5% 1206 R18-25
near NPN
transistors
Resistor networks
3 9*10k SIP10 RN1-3
bussed
network,
not 5 pairs
of resistors
Capacitors
5 100n 1206 C1-5
0 do not fit C6
Diodes
24 1N4148 THT
24 BAT54 SOT-23 512-BAT54
BAT 54
SMD
LEDs