Full Text Searchable PDF User Manual
Rotating Clock Divider
Eurorack Module User Manual v1.0.1 to 1.0.2
4ms Pedals
Features
•
Divide-by-1 to Divide-by-64, on 8 output jacks
•
CV Rotate jack to shift divide-by amount on all jacks
•
CV Reset to reset/re-sync all jacks
•
Jumpers or optional break-out panel:
◦
Select auto-reset (maximum 256 clocks)
◦
Select maximum divide-by amount (8/16/32/64)
◦
Gate or Trigger outputs
◦
Count-up or Count-down mode
•
UART header
◦
Connects to optional MIDI breakout panel
◦
Arduino-compatible
•
ISP header
◦
Connects to in-circuit programmer such as AVR ISP MKII for reprogramming code
•
Maximum input frequency 3kHz
•
4 H.P. Eurorack module
•
60mA power draw (+/-12V or +/-15V)
Jacks
•
Clock Input (3.5V to 15V clock, rising edge triggered)
•
CV Rotate (0V to +5V input)
•
CV Reset (5V to 15V trigger)
•
Divided Clock Outputs (8 jacks):
•
Divide-by (1+R)
•
Divide-by (2+R)
•
Divide-by (3+R)
•
Divide-by (4+R)
•
Divide-by (5+R)
•
Divide-by (6+R)
•
Divide-by (7+R)
•
Divide-by (8+R)
...where R is the CV Rotation (0 to 63)
PCB v1.0.2
PCB v1.0.1
Jumpers
There are six jumpers on the back, labeled 3, 4, 5, 6, 7, and 8. Each can be set with a jumper plug, or an optional break-out
panel with switches. The jumper positions vary among PCB versions. See the above photos to identify the location of
jumpers on your PCB (the PCB version is written in white letters near the /8 Jack).
Jumpers 3 and 4: Max Divide-by Range
Div
Range
Jumpers
Total Rotatable
Divide-by range
Divide-by amount on
jacks with no voltage
applied to CV Rotate
Jack (tables 2-5)
3
4
in
in
1 to 8
1 to 8
in
no
1 to 16
9 to 16
no
in
1 to 32
17 to 24
no
no
1 to 64
33 to 40
Jumpers 5 and 6: Auto-reset
Auto-
Reset
Jumpers
Auto-reset
with Divide-by range of...
5
6
1 to 8 1 to 16 1 to 32 1 to 64
in
in
32
64
128
256
in
no 16
32
64
128
no
in
24
48
96
192
no no none none
none
none
Jumper 7: Up-beat/Down-beat counting
Up/Down
Mode
in
Down-beat counting
no
Up-beat counting
Jumper 8: Gate/Trigger mode
Gate/Trigger
Mode
in
Gate mode
no
Trigger mode
Up-beat/Down-beat jumper:
In Up-beat counting, each jack fires after "N" number of pulses are counted on the input jack (where N is the divide-by-
number). So, after a Reset pulse, only the /1 jack will fire on the first clock pulse. On the next clock pulse, the /1 and the /2
jack will fire, then on the next pulse the /1 and /3 jacks will fire, etc... This is the default method for pcb v1.0 and v1.0.1,
unless it has been upgraded to v1.0.2 code.
In Down-counting, each jack fires when its count is 1. So all the jacks will fire after a Reset pulse, and then count up to "N",
and fire again when they start over at 1. This is called" down-beat counting" because all the jacks fire on the down-beat (first
clock pulse).
Gate/Trigger Mode jumper:
In Trigger mode, the jacks output a pulse width equal to that of the input clock (the pulse width is not multiplied or divided
proportionally to the jack's divide-by amount). This is the default method for pcb v1.0 and v1.0.1, unless it has been upgraded
to v1.0.2 code.
In Gate mode, the width of the output pulses are 50% of the total wave. For example, the /6 jack will stay ON for 3 clock
pulses, and then turn OFF for 3 clock pulses. For even numbered divisions (/2, /4, /6, /8, etc) the transitions happen on the
input clock's rising edge.
Point of interest:
In Gate mode, with odd-numbered divisions, the jack will turn ON on a rising edge of the input clock, and
then will turn OFF on a falling edge. For example, the /5 jack ought to stay on for 2.5 clock pulses, meaning it should go OFF
somewhere between the rising edge of clock pulses 2 and 3. Right in between these is the falling edge of pulse number 2, so
we can safely call it 2.5!
When in Gate mode (jumper 8), the difference between Up-counting and down-counting is simply that the gates are
inverted.
Auto Reset jumpers:
Jumpers 5 and 6 select the Auto-reset point, which causes the divide counters to reset after a certain number of clock pulses.
Note that divide-by amounts which are evenly divisable by the reset amount are not affected: e.g. with an auto-reset of 16,
divide-by outputs of 2, 4, 8, 16, etc are not changed.
Also, note that the CV Reset is independant of the Auto-reset. For example, Jack 7+R could be patched into the CV Reset
with jumpers 3, 4, and 5 in. This would cause a reset every 7 clocks, plus an additional reset every 16 clocks.
There are too many combinations of Auto-reset and Max divide amounts to show all combinations!
Example: Auto-reset of 16 (Jumper 5 in, no Jumper 6), with Max Divide-by of 8 (Jumpers 3&4)
IN:
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
17
18 19 20 21 22 23 24
25
26 27 28 29 30 31 32
3
X
X
X
X
X
X
X
X
X
X
5
X
X
X
X
X
X
7
X
X
X
X
Operation
Apply a clock signal to the Clock Input jack. Rising edges of 5V or greater will cause the internal dividing counters to be
incremented. Each jack has its own counter that counts from 1 to its divide-by-amount, and then resets back at 1. In up-beat
counting, each jack outputs a trigger pulse when its counter reaches the divide-by amount assigned to that jack. In down-
beat counting, each jack fires when its counter is 1. Typically, the outputs will patch to trigger-able or gate-able modules
(drum modules, ADSR envelope/transient generators, step sequencer clock input, etc..), but the RCD can also operate in the
audio frequency range, thus crudely stepping pitch downward.
Clock outputs (up-beat counting):
IN:
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
17
18 19 20 21 22 23 24
25
26 27 28 29 30 31 32
1
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
3
X
X
X
X
X
X
X
X
X
X
4
X
X
X
X
X
X
X
X
5
X
X
X
X
X
X
6
X
X
X
X
X
7
X
X
X
X
8
X
X
X
X
9
X
X
X
10
X
X
X
11
X
X
...
32
X
Clock outputs (down-beat counting):
IN:
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16
17
18 19 20 21 22 23 24
25
26 27 28 29 30 31 32
1
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
3
X
X
X
X
X
X
X
X
X
X
X
4
X
X
X
X
X
X
X
X
5
X
X
X
X
X
X
X
6
X
X
X
X
X
X
7
X
X
X
X
X
8
X
X
X
X
CV Rotation
By applying a CV signal to the CV Rotate jack, the clock divisions will rotate throughout the output jacks (
see table 2
). For
example, if you apply just over 1.0V, Jack 1+R/Red will go from Divide-by-1 to Divide-by-2, and Jack 2+R/Orange will
become Divide-by-3... up to Jack 8+R/White which will wrap ("rotate") around to become Divide-by-1. Applying more CV to
the Rotate Jack will continue the rotation: next Jack 1 becomes Divide-by-3, then Divide-by-4, then Divide-by-5, until it's
Divide-by-8 at the maximum input CV. Some non-linearities exist in the CV response, especially in the upper extreme.
See
diagram at end of this manual.
CV Reset
Applying a CV of 5V or greater to the CV Reset jack will cause all the divide counters to reset
on the next clock pulse
. So,
applying a reset pulse will not change the tempo, since the RCD will wait for the next clock pulse to actually do anything.
Counting will begin back at 1 after a Reset. A low/slow output on the RCD can be patched into Reset, or a second RCD
running on the same master clock can be set to run very slow and reset the first RCD after an arbitrary number of beats.
Rotation Tables
Table 2: Divide-by amounts at each jack, with max divide-by amount set to 8
(Jumper 3 in, Jumper 4 in):
Jacks
Voltage at CV Rotate Jack
<1.0V 1.00V - 1.65V 1.65V - 2.30V 2.30V - 2.95V 2.95V-3.60V 3.6V-4.30V 4.30V-5.10V >5.1V
1+R/Red
1
2
3
4
5
6
7
8
2+R/Orange
2
3
4
5
6
7
8
1
3+R/Yellow
3
4
5
6
7
8
1
2
4+R/Lt Green
4
5
6
7
8
1
2
3
5+R/Green
5
6
7
8
1
2
3
4
6+R/Blue
6
7
8
1
2
3
4
5
7+R/Violet
7
8
1
2
3
4
5
6
8+R/White
8
1
2
3
4
5
6
7
Table 3: Divide-by amounts at each jack, with max divide-by amount set to 16
(Jumper 3 in, no Jumper 4):
Jacks
Voltage at CV Rotate Jack
<
0.7V
0.7V -
1.0V
1.0V -
1.3V
1.3V -
1.7V
1.7V -
2.0V
2.0V -
2.3V
2.3V -
2.7V
2.7V -
3.0V
3.0V -
3.3V
3.3V -
3.7V
3.7V -
4.0V
4.0V -
4.3V
4.3V -
4.7V
4.7V -
5.1V
5.1V -
5.8V
>
5.8V
1+R/Red
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
2+R/Orange
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
3+R/Yellow
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
4+R/Lt Green
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
5+R/Green
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
6+R/Blue
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
7+R/Violet
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
8+R/White
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Table 4: Divide-by amounts with max divide-by amount set to 32 (Jumper 3 out, Jumper 4 in):
Jacks
Voltage at CV Rotate Jack
<
0.5V
0.68V 0.86V 1.04V 1.22V 1.38V 1.54V 1.70V 1.86V 2.02V 2.18V 2.36V 2.52V 2.68V 2.82V 3.00V
1+R/Red
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
2+R/Orange
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
3+R/Yellow
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
4+R/Lt Green
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
5+R/Green
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
6+R/Blue
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
7+R/Violet
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
8+R/White
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
7
(con't)
3.18V 3.34V 3.50V 3.68V 3.82V 4.00V 4.18V 4.36V 4.54V 4.72V 4.94V 5.17V 5.43V 5.80V 6.52V
>
6.52V
1+R/Red
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
2+R/Orange
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
3+R/Yellow
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
4+R/Lt Green
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
5+R/Green
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
6+R/Blue
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
7+R/Violet
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
8+R/White
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
Table 5: Divide-by amounts at each jack, with max divide-by amount set to 64 (no Jumper 3 or 4)
Jacks
Voltage at CV Rotate Jack
<
0.5V
0.68V 0.86V 1.04V 1.22V 1.38V 1.54V 1.70V 1.86V 2.02V 2.18V 2.36V 2.52V 2.68V 2.82V 3.00V
1+R/Red
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
2+R/Orange
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
3+R/Yellow
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
4+R/Lt Green
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
5+R/Green
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
6+R/Blue
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
7+R/Violet
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
8+R/White
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
(con't)
3.18V 3.34V 3.50V 3.68V 3.82V 4.00V 4.18V 4.36V 4.54V 4.72V 4.94V 5.17V 5.43V 5.80V 6.52V
>
6.52V
1+R/Red
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
2+R/Orange
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
1
3+R/Yellow
51
52
53
54
55
56
57
58
59
60
61
62
63
64
1
2
4+R/Lt Green
52
53
54
55
56
57
58
59
60
61
62
63
64
1
2
3
5+R/Green
53
54
55
56
57
58
59
60
61
62
63
64
1
2
3
4
6+R/Blue
54
55
56
57
58
59
60
61
62
63
64
1
2
3
4
5
7+R/Violet
55
56
57
58
59
60
61
62
63
64
1
2
3
4
5
6
8+R/White
56
57
58
59
60
61
62
63
64
1
2
3
4
5
6
7
div by 1:
div by 5:
div by 6:
div by 7:
div by 8:
div by 4:
div by 3:
div by 2:
CLOCK INPUT:
1
2
3
4
5
6
7
8
9
10
11
12
6
12
13
14
7
14
15
5
10
15
3
6
9
12
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
8
16
4
8
12
16
2
4
6
8
10
12
14
16
div by 1:
div by 5:
div by 6:
div by 7:
div by 8:
div by 4:
div by 3:
div by 2:
CLOCK INPUT:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
4
5
7
8
10
11
13
14
16
1
3
5
7
9
11
13
15
1
3
6
8
11
13
16
1
4
7
10
13
16
1
4
8
11
15
1
5
9
13
TRIGGER MODE, UP-BEAT COUNTING (NO JUMPERS IN 7&8)
GATE MODE, DOWN-BEAT COUNTING (BOTH JUMPERS 7&8)
Indicates falling-edge of clock input (all others are rising-edge)
PCB or Code v1.0.2
in
Rotate
Reset
0V - 5V
+5V
1+R
2+R
3+R
4+R
5+R
6+R
7+R
8+R
4ms Rotating Clock Divider
How CV Rotate Works
Example 1:
Example 2:
Example 3:
Mor
e CV R
otat
e
Less CV R
otat
e
1+R
div by 1 div b
y 2
div b
y 3
div b
y 4
div by 5
div b
y 6
div b
y 7
div b
y 8
2+R
3+R
4+R
5+R
6+R
7+R
8+R
1+R
div by 1 div
by
2
div
b
y 3
div
by
4
div
by
5
div
by
6
di
v
by
7
div
by
8
2+R
3+R
4+R
5+R
6+R
7+R
8+R
1+R
2+R
3+R
4+R
5+R
6+R
7+R
8+R
di
v
by
7
div by 1 div
by
2
div
b
y 3
div
by
4
div
by
5
div
by
6
div
by
8
1+R
2+R
3+R
4+R
5+R
6+R
7+R
8+R
div by 1 div
by
2
div
b
y 3
div
by
4
div
by
5
div
by
6
di
v
by
7
div
by
8
In this metaphorical illustration, applying a voltage to the Rotate jack makes the outer
circle of jacks rotate around the inner circle of divided clock signals. For a technical chart
of the exact voltages needed to cause exact rotations, see the User Manual.
1V applied to CV Rotate:
(Jacks shifted 1 unit clockwise)
1+R: div by 2
2+R: div by 3
3+R: div by 4
4+R: div by 5
5+R: div by 6
6+R: div by 7
7+R: div by 8
8+R: div by 1
2V applied to CV Rotate:
(Jacks shifted 2 units clockwise)
1+R: div by 3
2+R: div by 4
...
7+R: div by 1
8+R: div by 6
5.1V applied to CV Rotate:
(Jacks shifted 7 units clockwise)
1+R: div by 8
2+R: div by 1
...
7+R: div by 6
8+R: div by 7
This page assumes all jumpers are in their factory positions: i.e. only jumpers 3 and 4 are “in”
1V
2V
>5V
0V