Endless Loader

Endless Loader is a phone-first web server for browsing local .endl patches and loading one selected patch onto a connected Polyend Endless pedal. It is designed for Raspberry Pi OS on Pi 3B/4/5, and it also runs on Ubuntu-family Linux systems including Pop!_OS and standard Ubuntu desktops or mini PCs.

Part of my Open Workbench at erichdonahue.com.

What It Does

• Presents patches as a pedal-style control surface with labeled knobs.
• Discovers the Endless USB storage volume by label or UUID.
• Mounts the target volume when needed, copies the selected patch, and verifies the write with a read-back hash.
• Shows clear ready, pending, and error status through the USB panel and floating beacon.
• Updates an optional 1602 I2C LCD with the current patch name and compact knob labels.
• Uses optional companion metadata from edonahue/FxPatchSDK for richer descriptions, controls, actions, and links.
• Supports direct host USB control and Docker-friendly helper mode.

Screenshots

Desktop console:

iPhone-width console:

USB not-ready guidance:

Quick Start

Install system prerequisites on Raspberry Pi OS or Ubuntu-family Linux:

sudo apt install python3 python3-venv udisks2 util-linux

Install the app:

python3 -m venv venv
venv/bin/pip install -e ".[dev]"
cp config.example.toml config.toml

Edit config.toml:

library_root = "/path/to/endl/patches"

[usb]
mode = "host"
expected_label = "ENDLESS"
expected_uuid = ""

Run the server:

ENDLESS_LOADER_CONFIG=config.toml venv/bin/endless-loader

Open http://localhost:8080.

Platform Support

The current app code is portable across:

• Raspberry Pi OS on Pi 3B/4/5
• Ubuntu 22.04+ and other Ubuntu-family distributions with Python 3.10+
• Pop!_OS as one Ubuntu-family example, not a special-case target

For usb.mode = "host", the host needs:

• lsblk
• findmnt
• udisksctl

Those normally come from util-linux and udisks2.

USB Certainty Model

When usb.mode = "host", the app uses:

• lsblk --json to discover candidate block devices and partitions
• findmnt --json to determine the current mountpoint and read-only state
• udisksctl mount to mount the matched Endless volume when needed
• a temp-file copy plus atomic os.replace on the target volume
• fsync on the file and containing directory
• a read-back SHA-256 check when usb.verify_hash = true
• optional udisksctl unmount and power-off when usb.auto_eject_after_write = true

Use usb.expected_uuid for the strongest targeting. usb.expected_label is useful for first setup, but UUID matching avoids ambiguous writes if multiple removable volumes share a label.

Docker Helper Mode

Docker runs the web app in helper mode so the container does not manage host USB mounts directly.

Run the helper on the host:

ENDLESS_LOADER_CONFIG=compose.helper.toml venv/bin/endless-loader-usb-helper

Start the container:

docker compose up --build

The included Compose config routes helper calls to http://host.docker.internal:8755.

Companion Metadata

The app can show richer patch detail when a companion manifest exists at:

metadata/endless_loader_companion.json

inside the FxPatchSDK checkout, or at the corresponding raw GitHub URL. A sample companion tree is included under samples/fxpatchsdk-companion.

More Docs

• Setup
• Troubleshooting
• Design Notes

Screenshot Capture

Regenerate README screenshots with:

venv/bin/python scripts/capture_screenshots.py

The script requires Firefox on PATH.

Tests

Run the test suite with:

venv/bin/pytest