BeetTweek

Force Feed-Back Eurorack DSP Module

BeetTweek is a Eurorack format DSP module that introduces haptic feedback control to eurorack. The module's force feedback knob responds to incoming CV signals by generating tactile pulses, creating a direct physical connection between control voltages and user interface. Knob position, rotation velocity, and force parameters output CV signals that can be patched to other modules, enabling complex feedback loops and interactive control schemes within your rack. The module features multiple operational modes and configuration variants, taking full advantage of Eurorack's flexible patching paradigm to create dynamic control relationships between modules.

Features:
High Precision AS5048A 14-bit rotary sensor
Smooth 3-phase brushless motor provides haptic force feedback
4 24-bit DC-Coupled Audio Outputs, Low Pass Filtered.
4 16-bit ADC Anti-Alias Filtered Inputs.
80 RGB Knob Ring Indicator LEDs. With 8 Center LEDs
Firmware Updates Via SD Card
Fast 480MHZ Cortex-M7 Primary Processor and 168MHZ Cortex-M4 Knob Processor
8 RGB LEDs for inputs and outputs showing function depending on the current mode.
Mode, Function and 8 menu/input-output Buttons
Reverse Voltage Protection (Backwards Eurorack cable protection)
High Quality Laser Engraved Aluminum Front Panel (Not Shown)
Custom Chem-film coated and protected CNC milled knob.
Max Voltage Range: -8 to 8V inputs and outputs

Modes:
The following are the modes that can can be selected. Some modes are still in the planning and development phase, and if not finished by the end of the Kickstarter, will come out as firmware updates later.

Modes can be selected by pushing the MODE button and then subsequently selecting one of the 8 front panel buttons representing the available modes. Once selected, the module will switch to that mode. most modes have adjustable parameters, these can be controlled by pressing the FUNC button and then pressing a button. This will adjust a parameter of the Mode, usually pertaining to the button's corresponding input or output. Pressing a button without the FUNC modifier will cycle the characteristics of the input/output. for example turning an output sin wave into a square wave, switching from play to record, or tapping a clock input.

Spring Mode - In this mode, the Knob will always spring back to a given Input (CV) rotation. The Output's corresponds to the current knob rotation, velocity, and torque force. On its own this is a great way of temporarily "overriding" an external module parameter while knowing it will return to its original location. (Good for "solo" parts of a song"). By giving the module an input CV signal, the "target" or equilibrium rotation of the spring will change, this can be a great way to feed in a kick-drum GATE signal that you can feel in hand while performing.

DJ Mode - In this mode, the knob acts like a DJ turn table. The table can be spun forward and backward and it will retain its speed. There are 8 beat markers around the table. When the HEAD reaches a beat marker, a pulse is emitted. The table can also spin in synchronization to a external BPM. Matching its speed. A Direction input indicates the direction the table turns. The Table can also record and playback signals! The Record/Playback input dictates whether to record or playback. In playback mode the table can turned with your hand to create DJ scratching effects either with its own internal record buffer or an external sampler.

Torque-Friction Mode - In this mode, the knob is free to spin, while the input CV signals control how much torque and friction is applied to the knob, when a positive signal is used, the knob will rotate in a positive direction, while when a negative signal is used, the knob will rotate in a negative direction. Friction Input Creates friction against movement. Complex input signals can be used to generate complex forces on the knob.

Indent Mode - In this mode, the knob "snaps" to different even indented locations around the circle. The indents can be felt while adjusting, giving instant feedback as to what value the knob is currently at. Outputs corresponding to knob position.

Ratchet Mode - The knob rotates one way freely but not the other. Output CVs correspond to how much force you exert on the knob that is in the opposite of the ratchet direction. Input CVs adjust the ratchet follow trail, and direction.

Sequenced Pluck Mode (Planned) - In this mode, the module is fed a series of V/OCT note data, as the notes stream in, they appear as dots on the LED ring. The knob can then be used to "Pluck" the notes as the indicator runs over each note. Each Pluck can be felt in your hand. as each note is plucked an output note is generated. The pluck action can be dynamically muted on another input.

Torque-Curve Mode (Planned) - In this mode torque is applied to the knob from a given input signal synchronized by a GATE signal. Any signal received while the GATE is ON will be applied radially about the knob. Custom Torque Curves can be feed in by other modules. The module matches bpm based on the GATE signal, and expects the GATE signal to not change too suddenly. This mode can be used to create custom torque regions based on musical parameters.

More To Come!

Gesture Recording/Playback
BeetTweek has a common interface for recording gestures, while recording, the current mode behalves as normal while the module records your actions twisting the knob. When playing back your actions are played back and the knob spins accordingly. Playback is synced with the external CLK input. Playback and recording can be controlled by external CV using the Z (Record/Playback) input or by pressing a button:

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