Pepelats – audio looper with drums on Raspberry Pi

1. [Installation]
2. [Configuration]
3. [MIDI control]
4. [MIDI commands]
5. [Menu]
6. [Drums]
7. [Song]
8. [Screen]

Compatible Raspberry Pi

• Preferred models: 3B+, Zero-2W
• Excessive power models: 4, 5

MIDI controller, two options

• USB computer keyboard
• MIDI controller with 4 or more buttons sending notes. Connection by BlueTooth or USB

Looper status monitor, two options

• Web browser on any device connected to the same Wi-Fi as Looper
• LCD screen connected via HDMI or SPI

Looper features

• Multiple song parts (intro/verse/chorus/...). Parts have any number of parallel loops
• Parallel loops of variable length. Loops play together inside song part unless some of the loops are muted
• Quantization, loop's length, start/stop time is adjusted. Example: If a new loop is not exactly 2 bars log it will be truncated or extended with silence.
• Full history of undo/redo for each part. When adding new loop all saved undone loops, if any, are deleted – this is the only way to keep it simple.
• Parts may be cleared, loops may be deleted on the run. There are two different views for parts and loops.
• Silencing, deleting and re-arranging of loops in a part. A loop from the middle may be moved to the end to become the first loop to undo.
• Loading, saving of songs. Songs saved along with their drums.
• Delay tolerance – allows switching late up to 0.1s
• Binary distribution, installation is simple. License is required for full functionality.

Looper control and display

• Display looper state in attached screen (ex. 3.5" LCD screen) or in a Web browser. Web is preferable as it allows editing configuration files. Screen is more convenient if you have small screen attached to looper and do not change configuration.
• Control of looper via MIDI controller or computer keyboard.
• User configurable menu files - you can configure number of song parts, MIDI commands, etc. Menu files are text file – easy to change and understand.

Drum machine

• Drum machine with tree drum types: Style, MIDI and Loop
• MIDI drum may sync and control external MIDI client, e.g. IOS app. Midi clock is not supported, it may use start/stop, song position, and sys-ex messages to synchronize.
• Style patterns and MIDI commands are plain text files easy to edit. Style pattern looks like step sequencer in a text file.
• Loop drum uses one song part as drums. It plays along with other parts unless is stopped.
• All drums have volume control, random variations and breaks