Merge pull request #2 from microrack/sa-more-modules

sntxerror · web-flow · commit dc187bfa09c4 · 2025-12-30T16:21:42.000+04:00
More modules
diff --git a/mod-eq/README.md b/mod-eq/README.md
@@ -9,6 +9,10 @@
 5. mid level (±10 dB @ 2.5kHz)
 6. low level (±15 dB @ 80 Hz)
 
+# Description
+
+Classic three-band equalizer with low, mid, and high frequency controls for shaping the tonal balance of your signal. Each band can be boosted or cut to fine-tune the mix.
+
 ## Power consumption
 
 216 mW
diff --git a/mod-in-63/README.md b/mod-in-63/README.md
@@ -11,9 +11,26 @@
 7. right channel signal level
 8. +5 V pull-up (phantom power)
 
-CV mode
-CV on: no DC block
-CV off: DC block
+## Description
+
+Stereo input preamplifier with wide gain range from -∞ to +60 dB. Features a +5V pull-up switch for powering electret microphones and expression pedals, and a CV/DC block mode switch for handling both audio and control voltage signals.
+
+Each channel has 3 output pins and a signal level indicator.
+
+- **CV mode on**: no DC blocking, passes DC offset (for CV sources)
+- **CV mode off**: DC blocking enabled (for audio signals)
+
+## Signal type reference
+
+| Signal type | +5V | CV mode | Gain |
+|-------------|-----|---------|------|
+| Line input | off | off | low |
+| Dynamic/piezo mic | off | off | high |
+| Electret mic | on | off | high |
+| CV source | off | on | as needed |
+| Sustain/expression pedal | on | on | low |
+
+**Note:** Condenser microphones requiring 48V phantom power are not supported.
 
 ## Power consumption
 
diff --git a/mod-jacket/README.md b/mod-jacket/README.md
@@ -5,6 +5,12 @@
 1. microrack I/O ×3
 2. mono 3.5 jack modular I/O
 
+## Description
+
+Passive adapter between mono 3.5mm jacks and microrack pins. Each jack is connected to two pins.
+
+Use it to send signals from microrack to a modular system, or to receive signals from a modular system into microrack.
+
 ## Power consumption
 
 24 mW
diff --git a/mod-key/README.md b/mod-key/README.md
@@ -6,8 +6,16 @@
 2. key gate inputs (2 per each key)
 3. gate output
 4. 1 V/oct output
-5. key stylo pads
+5. key stylus pads
  
+## Description
+
+Stylus keyboard that outputs CV/Gate signals.
+
+Connect an alligator clip wire or male-female jumper to the +5V pins. Now you can play: touching the keyboard pads outputs a Gate signal (5V) and a 1 V/oct CV signal (0V for the first C note, 1V for the last C note). The CV signal remains constant between key presses.
+
+Each pad is also connected to pins, allowing you to connect external gate/trigger sources to activate notes as if you were playing them by hand.
+
 ## Power consumption
 
 300 mW
diff --git a/mod-lpg/README.md b/mod-lpg/README.md
@@ -11,6 +11,23 @@
 7. LPG/Combo mode switch (LPG has more resonance, Combo is closer to VCA with more high frequencies)
 8. signal pass level indicator
 
+## Description
+
+Vactrol-based lowpass gate module. A lowpass gate combines a VCA and a lowpass filter in one circuit — as the gate opens, both volume and brightness increase together. Vactrols provide a natural decay characteristic: even with instant trigger, the sound fades out smoothly due to the vactrol's inherent release time.
+
+### Control methods
+
+The gate can be controlled in three ways:
+
+- **Level knob**: manually open the gate
+- **CV level input**: control via CV signal; the Depth knob acts as an attenuverter
+- **Trigger input**: accepts gates or triggers; gates are converted to short pulses for sharp attack with natural vactrol decay. The Depth knob also affects trigger polarity: turn right for pulses on gate rise, turn left for pulses on gate fall.
+
+### Modes
+
+- **LPG mode**: more resonance, classic lowpass gate sound
+- **Combo mode**: closer to VCA behavior with more high frequencies passing through
+
 ## Power consumption
 
 384 mW
diff --git a/mod-midi/README.md b/mod-midi/README.md
@@ -17,6 +17,47 @@
 13. push button (pin 38)
 14. USB type-C for firmware update and serial connection (on bottom side)
 
+## Description
+
+ESP32-D0 based programmable module with 4 MB flash, MIDI input, analog I/O, and user interface.
+
+### Analog inputs (pins 36, 37)
+
+Level-shifted inputs that convert -5V to +5V signals to 0–3.3V range suitable for the ESP32 ADC.
+
+### Analog outputs (pins 26, 25, 33)
+
+All three outputs support PWM. Pins 26 and 25 also have 8-bit DAC. Each output has a first-order lowpass filter (1 kHz cutoff) and level shifting to convert 0–3.3V back to -5V to +5V range.
+
+### Gate outputs (pins 12, 13)
+
+Direct microcontroller outputs for gate/trigger signals. These pins should only be connected to input pins of other modules.
+
+### Digital I/O
+
+Some ESP32 pins are directly exposed without any protection circuitry. Only 0–3.3V signals are safe — **do not connect these to other microrack modules!**
+
+### MIDI
+
+- **MIDI input**: TRS type-A jack with optocoupler isolation, connected to pin 16
+- **MIDI output**: Pin 17 and 3.3V power exposed with 200Ω series resistors for connecting an external MIDI jack
+
+### User interface
+
+- **OLED display**: 128×64 monochrome HS96L03W2C03, I2C on pins 21 and 22
+- **Rotary encoder**: Quadrature encoder on pins 34, 35 (active low with pull-up); push button on pin 39 (active low with pull-up)
+- **Button**: Separate push button on pin 38 (active low with pull-up)
+- **Reset button**: Hardware reset
+- **LEDs**: Chain of 4 addressable SK6805-EC20 LEDs on pin 23 (2 on bottom side, 2 under the display)
+
+### USB and programming
+
+CP2102 USB-UART converter connected to the main ESP32 UART. DTR/RTS lines are wired for automatic bootloader mode entry via esptool/Arduino IDE. Use for firmware updates and serial communication.
+
+### Wireless
+
+PCB antenna for WiFi and Bluetooth.
+
 ## Power consumption
 
 660 mW
diff --git a/mod-noise/README.md b/mod-noise/README.md
@@ -2,6 +2,8 @@
 
 <img src="mod-noise.png" width="245">
 
+## Interface
+
 1. T&H/S&H signal input
 2. tracking gate input
 3. pink noise output
@@ -10,6 +12,29 @@
 6. T&H/S&H signal output
 7. manual tracking touch pad
 
+This module contains two independent sections: a noise generator and a track & hold / sample & hold circuit.
+
+## Noise generator
+
+The noise generator provides two simultaneous outputs with different spectral characteristics:
+
+- **Pink noise** — has equal energy per octave, resulting in a warmer, more natural sound. Commonly used for audio testing, ambient textures, and as a modulation source.
+- **Blue noise** — has increasing energy at higher frequencies, producing a brighter, more hissing character. Useful for adding high-frequency content or as a different flavor of random modulation.
+
+## Track & Hold / Sample & Hold
+
+This section can operate in two modes depending on how the gate and trigger inputs are used:
+
+### Track & Hold (T&H)
+
+When a gate signal is applied to the **tracking gate input**, the circuit continuously follows (tracks) the input signal while the gate is high. When the gate goes low, the output holds the last tracked voltage. This is useful for capturing a voltage at a specific moment determined by the gate signal.
+
+### Sample & Hold (S&H)
+
+When a trigger is applied to the **sampling trigger input**, the circuit instantly samples the current input voltage and holds it until the next trigger. This creates the classic "stepped random" effect when used with a noise source, or can be used to quantize continuous signals in time.
+
+A **touch pad** is provided for manually injecting a track gate, allowing hands-on interaction with the T&H function.
+
 ## Power consumption
 
 420 mW
diff --git a/mod-out-35/README.md b/mod-out-35/README.md
@@ -2,6 +2,30 @@
 
 <img src="mod-out-35.png" width="235">
 
+This is an output module for connecting headphones, external amplifiers, mixers, or powered speakers. Available in two versions: with a 3.5mm jack (this one) and with a 6.3mm jack.
+
+## Features
+
+The module includes a **volume control** knob and **level indicators** for both left and right channels.
+
+### Mono / Stereo modes
+
+The module can operate in two modes, selected by a switch:
+
+- **Mono mode** — all 12 inputs are summed together and sent to both left and right output channels.
+- **Stereo mode** — 6 inputs are summed for the left channel and 6 inputs are summed for the right channel, providing true stereo output.
+
+### Built-in speaker (3.5mm version only)
+
+The 3.5mm version features a built-in speaker that automatically activates when nothing is plugged into the output jack. The speaker is connected to the right channel, so it works in:
+
+- **Mono mode** — signal is heard through the speaker
+- **Stereo mode** — only right channel inputs are heard (almost twice as loud)
+
+For maximum speaker volume, use stereo mode and route your signal to the right channel inputs.
+
+## Interface
+
 1. left channel signal indicator
 2. output volume
 3. left/mono channel input
diff --git a/mod-out-63/README.md b/mod-out-63/README.md
@@ -10,6 +10,19 @@
 6. right channel signal indicator
 7. mono/stereo mode switch
 
+This is an output module for connecting headphones, external amplifiers, mixers, or powered speakers. Available in two versions: with a 3.5mm jack and with a 6.3mm jack (this one).
+
+## Features
+
+The module includes a **volume control** knob and **level indicators** for both left and right channels.
+
+### Mono / Stereo modes
+
+The module can operate in two modes, selected by a switch:
+
+- **Mono mode** — all 12 inputs are summed together and sent to both left and right output channels.
+- **Stereo mode** — 6 inputs are summed for the left channel and 6 inputs are summed for the right channel, providing true stereo output.
+
 ## Power consumption
 
 780 mW
diff --git a/mod-sat/README.md b/mod-sat/README.md
@@ -2,13 +2,25 @@
 
 <img src="mod-sat.png" width="225">
 
+## Interface
+
 1. signal input
 2. bias CV control
 3. signal output
 4. saturation bias
 5. output volume
 6. saturation drive control
 
+Saturator adds harmonic richness and grit to your signal by soft-clipping the waveform. At low drive settings it warms up the sound with subtle harmonic content, similar to analog tape or tube gear. Pushing the drive higher introduces more aggressive distortion, from crunchy overdrive to full-on fuzz.
+
+**Drive** — controls the intensity of signal distortion.
+
+**Bias** — alters the signal waveform distortion. In the far-left position, amplitude clipping is applied to the lower half-wave; in the far-right position, it affects the upper half-wave. In the center, distortion is symmetrical for both waveforms.
+
+The bias parameter has a **CV input**, allowing dynamic modulation of the distortion character with envelopes, LFOs, or other control signals.
+
+**Output volume** — adjusts the output level after saturation, letting you tame the boosted signal or match levels with the rest of your patch.
+
 ## Power consumption
 
 348 mW
diff --git a/mod-seq/README.md b/mod-seq/README.md
@@ -2,6 +2,8 @@
 
 <img src="mod-seq.png" width="495">
 
+## Interface
+
 1. ×4 manual step trigger pads
 2. reset input
 3. clock input/output
@@ -13,9 +15,45 @@
 9. gate output
 10. CV output
 11. ×4 step enable
-12. counter/sequnecer chain connector
+12. counter/sequencer chain connector
 13. ×4 step CV
 
+A 4-step sequencer with chaining capability — connect multiple modules together to extend the sequence length indefinitely.
+
+## Basic operation
+
+By default the sequencer cycles through 4 steps. Each step has:
+- **Gate switch** — enables gate output (5V) for this step
+- **CV knob** — sets the control voltage (0–5V) for this step
+
+If a step is disabled, it can still be triggered manually using the **touch pad**.
+
+## Clock
+
+The sequencer has a **built-in clock** with adjustable tempo. The clock speed can also be modulated via CV input.
+
+The **clock input/output** pin serves dual purpose:
+- Connect an external clock source to sync the sequencer
+- Tap the internal clock to drive other modules
+
+> **Known issue:** external clock requires a low-impedance output. 1kΩ high-impedance outputs or open emitter outputs will not work reliably.
+
+## Run/Stop
+
+The **run/stop switch** starts and stops the sequencer. When using chained sequencers, use the switch on the last module in the chain.
+
+## Per-step outputs
+
+Individual step outputs function as a counter — they fire sequentially regardless of whether steps are enabled or disabled. Useful for triggering external events on specific steps.
+
+## Changing sequence length
+
+Connect the output of step N+1 to the reset input to create a shorter sequence of N steps. For chained sequencers, this only works when connected to the last module in the chain.
+
+## Chaining
+
+Multiple sequencers can be connected via the **chain connector** to extend the sequence length. The **gate** and **CV outputs** are open emitter, allowing them to be directly connected together when chaining modules.
+
 ## Power consumption
 
 420 mW
diff --git a/mod-vca/README.md b/mod-vca/README.md
@@ -2,6 +2,8 @@
 
 <img src="mod-vca.png" width="315">
 
+## Interface
+
 1. 3× gain knobs
 2. gain CV modulation inputs
 3. signal inputs
@@ -10,6 +12,26 @@
 6. static +5 V and -5 V outputs
 7. attenuator/attenuverter switch
 
+A three-channel mixer based on a ring modulator circuit.
+
+Each channel has a **signal input**, a **gain knob**, and a **CV input** for voltage-controlled gain. The CV input is summed with the knob position, allowing external modulation around the manual setting. Each channel also has its own **individual output**, plus there's a **mix output** that sums all three channels together.
+
+## Attenuator vs Attenuverter
+
+A switch selects between two modes for all channels:
+
+**Attenuator mode** — the gain knob scales the signal from 0% to 150%. The signal amplitude is reduced but the polarity stays the same. Knob at minimum = silence, knob at maximum = maximum gain.
+
+**Attenuverter mode** — the gain knob goes from −150% through 0% to +150%. At center position the signal is silent. Turning left inverts and scales the signal, turning right scales it normally. This allows you to flip the polarity of control voltages, create inverted copies of modulation signals, or subtract signals in the mix output.
+
+Attenuverters are essential for shaping modulation depth and direction — for example, making an LFO sweep a filter downward instead of upward.
+
+> **Known issues:** the second and third channels are slightly noisy, and in attenuator mode the silence point may not be exactly at the minimum knob position.
+
+## Static voltage outputs
+
+The module provides **+5V** and **−5V** reference outputs, useful for offsetting signals or as fixed CV sources.
+
 ## Power consumption
 
 1020 mW
diff --git a/mod-vcf/README.md b/mod-vcf/README.md
@@ -2,6 +2,8 @@
 
 <img src="mod-vcf.png" width="295">
 
+## Interface
+
 1. signal input
 2. cutoff modulation input
 3. signal output
@@ -10,6 +12,30 @@
 6. resonance control
 7. cutoff frequency control
 
+A voltage-controlled filter based on a diode ladder topology. Filters shape the harmonic content of a signal by attenuating frequencies above or below a certain point.
+
+## Filter modes
+
+The **HP/LP switch** selects between two modes:
+
+**Lowpass (LP)** — frequencies below the cutoff pass through, higher frequencies are attenuated. This removes brightness and harshness, creating warmer, darker tones. The classic subtractive synthesis sound.
+
+**Highpass (HP)** — frequencies above the cutoff pass through, lower frequencies are attenuated. This thins out the sound, removing bass and body while keeping the higher harmonics.
+
+## Cutoff
+
+The **cutoff frequency** determines where the filter starts working. In lowpass mode, everything above this frequency gets quieter; in highpass mode, everything below gets quieter. The cutoff knob sweeps this frequency across the audible range.
+
+## Resonance
+
+The **resonance** control adds emphasis at the cutoff frequency by feeding some of the filter's output back into its input. At low settings it adds a subtle peak, making the cutoff point more pronounced. Higher resonance creates a sharper, more aggressive peak that can make the filter "sing" or even self-oscillate at extreme settings.
+
+## CV modulation
+
+The **CV input** allows external control of the cutoff frequency — connect an envelope for dynamic filter sweeps, an LFO for wobble effects, or a keyboard CV for tracking pitch.
+
+The **depth knob** is an attenuverter that controls how much the CV affects the cutoff and in which direction. Center position = no modulation. Turn right for positive modulation (CV increases cutoff), turn left for inverted modulation (CV decreases cutoff).
+
 ## Power consumption
 
 540 mW
diff --git a/mod-vco/README.md b/mod-vco/README.md
