Greenface Labs THE SPANKULATOR User manual

THE SPANKULATOR
USER MANUAL
Greenface Labs -- 2023

TABLE OF CONTENTS
Quick Start .................................................................................................................................3
Overview ................................................................................................................................... 4
Features..............................................................................................................................................4
Signals ................................................................................................................................................4
Operation ...................................................................................................................................7
General Operation .............................................................................................................................. 7
Open Source Project ...........................................................................................................................6
Trigger ................................................................................................................................................8
Repeat Mode.......................................................................................................................................8
CV Scale..............................................................................................................................................9
Sig In...................................................................................................................................................9
Screen Saver .......................................................................................................................................9
Function Details......................................................................................................................... 9
Up ..................................................................................................................................................... 11
Down ................................................................................................................................................ 12
Stretch.............................................................................................................................................. 13
Toggle............................................................................................................................................... 14
Maytag.............................................................................................................................................. 15
LFO................................................................................................................................................... 16
User .................................................................................................................................................. 18
Bounce..............................................................................................................................................20
WiFi................................................................................................................................................... 21
Terminal Mode.................................................................................................................................. 25
Settings.............................................................................................................................................28

QUICK START
The Spankulator can be used in an endless variety of ways, but here is a great way to start
exploring. These instructions are for use with a Moog Mother-32 but can be easily adapted to
most modular synthesizers. Note - you may need to set the encoder type in Settings first.
MOTHER-32 SET-UP
•VCA Mode –EG (use the envelope generator)
•VCO Mod Amount –Zero
•VCF Mode –Low Pass
•VCF Mod Source –EG
•VCF Mod Amount –0%
•Cutoff –200Hz
•Resonance –50%
•Attack –5%
•Decay 10%
•Sustain –Off
•Frequency –50%
•Pulse Width –50%
•VCO Wave - Pulse
•Octave –4
•Note –8
SPANKULATOR SET-UP
•Fxn –Down (use default parameters as shown in images below)
•Start Pulse Len –100
•End Pulse Len –10
•Num Pulses –10
•Randomness –0
•Initial Delay 100
•Repeat –On
•CV Scale –50%
Connect the Spankulator Trig Out to the M-32 Gate Input, Tog Out to the M-32 VCF Cutoff
Input and CV Out to the M-32 VCO Lin Input. Press Trigger on the Spankulator and you should
hear a sound much like that found here.

OVERVIEW
The Spankulator is a WiFi-enabled multi-function Eurorack module. Its main function is to
generate a trio of coordinated analog and digital signals which can be used in an endless
variety of ways. While each output generates familiar signals, it is the coordination of these
signals and the methods of control that make the Spankulator special.
SIGNALS
•Trig Out –Digital signal that consists of pulses of varying width.
•Tog Out –Digital signal that toggles at the end of every sequence.
•CV Out –Analog signal (+/- 5 volt) that depends on the Function. Usually, it is relative to
the pulse width of the Trig Output. This signal is modified using the CV controls.
•Trigger In –Digital input. Operation is triggered with a 0 to 5 volt transition on this
input. This also serves as the External Clock when Ext Clk mode is enabled.
•Sig In –Analog signal input. Range: +/- 5 volt
FUNCTIONS
•5 Spank types –Up, Down, Stretch, Toggle and Maytag
•LFO with 4 waveforms –Sine, Inv Sine, Ramp Up, Ramp Down
•Bounce –A DVM plus a quantizable sample and hold. DC and optional AC modes
•User Mode –For sending sequences of Spanks and/or LFO bursts
•WiFi Mode –For configuring WiFi connection
•Settings –For module configuration, factory reset, etc.
FEATURES
•128x64 graphic display enhances usability
•Web and Terminal interfaces provide rich user experiences with the addition of
computer resources like a keyboard, mouse, display and scripting.
•All settings are stored in Flash memory so that they are retained when power is off
•Selectable Single Shot or Repeat mode
•CV scale, offset and value are independently controllable via CV pot and Sig In
•CV Out can be Quantized
•Randomness can be added to most function ranging from 0 to 99%
•External Clock mode
•Inputs and Outputs are protected against damage during typical use

Figure 1 - Front Panel

OPEN-SOURCE PROJECT
The Spankulator is an Open-Source project that has an Arduino 33 IoT at its core. The code is
written in C++ and makes use of several public domain code libraries for managing the various
purchased hardware components such as the display and the FRAM non-volatile memory.
Because it is Open Source, in addition to being used by musicians and sound designers to
create new and amazing sounds, the Spankulator can be used by students and entrepreneurs
to create new, amazing modules. And, of course, the open-source community will generally
improve the product as times goes along. Links to the design repositories can be found on the
Spankulator web page.

OPERATION
GENERAL OPERATION
(Please see the Terminal and Web Interface sections for more details)
•The Function is selected using the +and –buttons.
oTerminal uses the +and –keys.
oWeb Interface has dedicated Function buttons.
oEach function has one or more parameters.
•Parameters are adjusted using the arrow keys and the Adjust knob.
oParameters are selected using the up and down arrows.
oDigit to be adjusted is selected by using the right and left arrows.
oWhen entering strings, holding the right or left arrow down for 2 seconds
inserts (right) or deletes (left) a character.
oUse the Adjust knob to increment and decrement the selected digit.
oParameter values may be directly entered using the Terminal or Web Interface.
•Operation of each function is triggered by a variety of methods.
oPressing the Adjust button.
oReceiving a low to high transition on the Trig In jack.
oTerminal uses the !key to trigger.
oWeb Interface has a dedicated Trigger button.
•Trigger may be single-shot or repetitive.
oPress the Repeat button to toggle the Repeat mode.
oTerminal uses the *key to toggle Repeat mode.
oWeb Interface has a dedicated Repeat button.
•CV Out amplitude, offset and value can be adjusted by a variety of methods.
oUse the CV potentiometer or Sig In. Select adjust functions in Settings.
oTerminal uses the S, Oand ckeys plus up to four digits. (Use the zkey to refresh
the screen after setting this parameter to see the result.)
oWeb Interface has a dedicated Slider control for each function.
•CV Quantization can be selected in Settings by the following methods.
oTerminal uses q0 to turn Quantization OFF.
oTerminal uses q1 to turn Quantization ON.

NOTE ON CV INPUT/OUTPUT
The Spankulator is designed to operate on a +/-5V range. There are usage scenarios that
require a different range (0-8V for example). For these scenarios, it is recommended that an
external biasing module be used. The 4MS SISM module is recommended, but there are many
others that would work.
TRIGGER
The Spankulator is controlled by the user issuing Commands. Commands are initiated by
pressing the front panel buttons or by using the Web or Terminal interfaces. Regardless of the
source of the command, it will be called either a command or a keypress in this document.
The various functions that the Spankulator performs are called “Spanks” and will be referred to
as such in this document.
All the Spankulator’s functions are activated by a trigger. Triggers can come from various
sources:
•Pushing the Trigger (Adjust) knob.
•Receiving a 0 to 5V transition on the Trig In jack.
•Receiving a Trigger command from either the Web or Terminal interface
When a Trigger is received, the Spankulator will execute a Spank that sends pulses at the Trig
Out jack and varying voltage levels at the CV Out jack. When the Spank ends, the Tog Out jack
will switch polarity from one to zero or vice versa.
REPEAT MODE
If Repeat is set to OFF, the Spankulator will remain in whatever condition it was in when the
Spank ended until it receives another Trigger.
If Repeat is set to ON, the Spank will continuously repeat.
In either case, receipt of another Trigger or Command will interrupt the Spank, stopping
execution until a new Trigger is received.
The Trigger Indicator will be activated when a trigger is received and will be turned off when
the trigger ends. The Trigger Indicator is a Red LED on the front panel and is a widget in the
Web Interface. It is textually indicated on the Status line in Terminal mode.

CV OUT
The CV Out signal ranges from -5V to +5V. The range can be adjusted from 0 to 100% by using
the CV controls (CV Pot or Sig In). Use Settings to select Scale as the Adjust Function.
The CV Out signal can be offset by -5V to +5V. The offset can be adjusted using the CV
controls. Use Settings to select Offset as the Adjust Function.
When the Trigger isn’t active, the CV Out Value can be directly set using the CV controls.
Use Settings to select Value as the Adjust Function.
Web mode has a dedicated slider control for each CV parameter, and Terminal mode uses the
S, O and c keys. See the table of remote commands for more details.
SIG IN
The Signal In jack has a range of -5V to +5V. It is used by the CV Controls and the Bounce
function.
For the Bounce function, Sig In is split into two parts, one AC coupled, and the other DC
coupled. These signals are then scaled and biased to the 0 to 3.3V signal that the Arduino
requires. More details about the Bounce function can be found later in this document.
SCREEN SAVER
In order to maximize display life, the display will turn off after a set time. The default time is 15
minutes. The time can be set in the Settings function with a range of 1 to 9999 minutes.
Press any button or push the Trigger knob or send a ‘z’ via remote to bring the display back.
RESET ON POWER ON
Holding down the + button when powering up will force a full reset to factory defaults. Unlike a
reset done in Settings, this reset includes the WiFi parameters.

FUNCTION DETAILS
The Spankulator has ten functions. These are listed below with their associated command
index. Details for each function follow.
0. Up
1. Down
2. Stretch
3. Toggle
4. Maytag
5. LFO
6. User
7. Bounce
8. Web
9. Settings