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4ms rotating clock divider User Manual

Made by: 4ms
Type: User Manual
Category: Music Pedal
Pages: 8
Size: 2.59 MB

 

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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)

 


background image

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

 


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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

 


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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.

 


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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

 


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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

 


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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

 


background image

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

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

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

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