https://github.com/othmar52/eurorack-step-sequencer-2x8
Draft of an arduino based simple eurorack sequencer
https://github.com/othmar52/eurorack-step-sequencer-2x8
eurorack eurorack-diy sequencer
Last synced: 3 days ago
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Draft of an arduino based simple eurorack sequencer
- Host: GitHub
- URL: https://github.com/othmar52/eurorack-step-sequencer-2x8
- Owner: othmar52
- Created: 2025-09-15T08:21:02.000Z (9 months ago)
- Default Branch: main
- Last Pushed: 2025-09-15T09:52:34.000Z (9 months ago)
- Last Synced: 2025-09-15T11:25:08.554Z (9 months ago)
- Topics: eurorack, eurorack-diy, sequencer
- Language: C++
- Homepage:
- Size: 5.86 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# **Eurorack Step Sequencer - 2x8 or 1x16**
This is currently a concept for an Arduino-based step sequencer, configurable as either 2x8 or 1x16. The shift buttons next to the display grant access to a variety of per-sequence settings.
For example, by holding **Shift 1** and turning the **SEQ1 STEP1** potentiometer, you can adjust the gate length for **all steps** within **SEQ1**. The available values will be shown on the display within the shift menu.
A potential drawback, though not a dealbreaker, is that after releasing the shift button, you must return the potentiometer to its original position to maintain the sequence's intended state.
Here are some ideas for the shift functions:
* Gate length
* Sequence length
* Glide
* Step select
* Play direction (including chain instances)
* Voltage range (0-1V, 0-2V, 0-3V)
* Quantizer
* Auto-reset (jumps to step 1 when the incoming clock pauses)
* Clock division
* Chain instances
* Octave shift
* Inactive step skip
* Step repeat
* Ratcheting
* Sequence start
* Probability
* Vibrato
* Speed
* Amplitude
* Waveform
* Reset all (activated by a simultaneous 3-second press)
## Planned panel layout
```
┌───────────────────────────────────────────────┐
│ ○ ○ │
│ │
│╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮│ SEQUENCE1
││ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● ││ 8 Potentiometer
│╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯│
│ ○ ○ ○ ○ ○ ● ○ ○ │ 8 indicator LEDS (playhead)
│ ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬ │
│ ┴ ┴ ┴ ┴ ┴ ┴ ┴ ┴ │ 8 Switches step ON/OFF
│ │
│╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮ ╭───╮│ SEQUENCE2
││ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● │ │ ● ││ 8 Potentiometer
│╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯ ╰───╯│
│ ○ ○ ○ ○ ○ ● ○ ○ │ 8 indicator LEDS (playhead)
│ ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬ │
│ ┴ ┴ ┴ ┴ ┴ ┴ ┴ ┴ │ 8 Switches step ON/OFF
│┌─────────┐ SEQUENCE1 SEQUENCE2 │
││ DISPLAY │ ● ○ ○ ├──┤ ○ ○ ├──┤ │ 2 momentary switches next to the display
││ 128x64 │ │ (shift functions for each sequence)
│└─────────┘ ● ○ ○ ○ ○ │
│ ○ ○ │
└───────────────────────────────────────────────┘
both sequence I/O
CLK IN CV OUT BOOST (switch to 10V CV output)
○ ○ ├──┤
○ ○
RST IN GATE OUT All 4 jacks should have indicator LEDS
```
## Parts
### Arduino
Arduino MEGA has all required digital and analog pins onboard. it also should fit below the frontpanel.
In case we use a Nano or similar we would need to extend the existing pins with
- MCP23017 (16 additional digital pins)
- CD4051 (8 additional analog pins)
### 2-channel DAC
MCP4822 seems to be suitable
### 4 channel op amp
LM324N
### 8 jacks
https://www.3u-shop.de/p/3-5mm-monobuchse-50-stueck
https://www.uk-electronic.de/onlineshop/product_info.php?products_id=4868
### 16 Potentiometer
https://www.digikey.at/en/products/detail/bourns-inc/PTV09A-4025U-B103/3781137
### Display
SSD1306 https://www.az-delivery.de/en/products/0-96zolldisplay
### Leds
24 x https://www.reichelt.at/at/de/shop/produkt/flat-led_5mm_rot_350_mcd_120_-363941
### Switches
18 x https://www.reichelt.at/at/de/shop/produkt/miniatur-kippschalter_ein-ein_3_a_250_v-285987
### 2 Buttons / momentary switches