Suffice

Suffice is a terminal-based tool for controlling a cycling trainer, so you can pound pedals while peddling code.

Goals

• modes: ERG, Level, maybe Sim if I'm feeling spicy
• run as a daemon, see status of the trainer in starship
• record FIT (or similar) files to prove your sweat

Non Goals

• a persistent UI, HUD, etc.
• non-cycling machines

Roadmap

v1 Features

• properly wrap the Trainer in an Arc and handle notifications in a thread
• basic REPL controls
• capture basic sensor data: power, speed, cadence
  • and display it usefully
• make sure ERG and Level mode seem to work
• record sessions in FIT files
• add screenshots/screencasts
• implement daemon mode
• starship integration
• faked distance data (what algorithm does other software use?)
• proper cli args
  • help
  • verbose/quiet mode
  • connect-test option
• bling
  • make gauges for resist/power level
  • show a basic graph of stats
  • animations / exhortations

v2+ Features

• other connection types: ANT+ / WiFi
• workouts
• Sim mode

DevEx

• tests and measuring test coverage
• CI checks
• crates.io publication
• tokio tracing logs
• better error handling generally instead of reckless unwraps everywhere
• github branch protection
• docstrings etc.

Bugs

• sometimes the FIT file has more than one session -- why?
• sometimes the trainer stops sending data back
• rapid commands only slowly take effect (because we only loop events every 1s)

Resources Used

• the official FTMS spec
• relevant prior art in python: pycycling the underlying BLE library bleak and some useful info about the trainer I was developing against
• examples from the key rust BLE library btleplug
• the tokio examples -- quite useful in the many false starts at working out how to deal with the fundamentally async nature of the system
• not directly relevant, but a fascinating blog post on creating a FTMS
• making sense of tokio + ratatui
• verifying that the fit files were produced correctly