Files
goodwe-addon/README.md
T
adminandClaude Opus 5 266684bed7 Field guide as a 10-page A4 PDF, one page per step
Rebuilt the guide as something usable on site rather than a document to read
at a desk: strict order of operations, DO / VERIFY / IF NOT blocks per step,
pass-fail gates in a table, a printable sign-off sheet, and troubleshooting
keyed by symptom rather than by subsystem.

Includes real screenshots of the add-on's own Web UI - captured by running it
against stub data - showing the healthy state and the misconfigured one side
by side, because telling those apart at a glance is the single most useful
skill on site. Plus the ESPHome step from a live builder.

The text lives only in docs/build_guide.py, which renders the HTML and drives
headless Chrome to produce the PDF. One source: a Markdown copy would
inevitably drift from the PDF someone is holding in a cellar.

Pagination is enforced, not hoped for. Each section must render under the A4
printable height (1039 px at 96 dpi) or Chrome silently spills it onto a second
page and the page numbers stop matching the step numbers. Measured every
section rather than eyeballing it: the Web UI reference page was 1170 px and is
now 1017 px, and the PDF comes out at exactly one page per section.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016NckgXecasQb2eSsPYNSW6
2026-08-23 01:44:08 +02:00

3.1 KiB

GoodWe RS485 Controller — Home Assistant add-on repository

Replaces a GoodWe battery inverter's vendor controller with a local one: holds net grid exchange at zero by emulating the inverter's smart meter over RS485, and runs the monthly battery maintenance cycle the vendor box was doing.

repository.yaml            add-on repository metadata
goodwe_controller/         the add-on
  config.yaml              manifest + options schema (the per-site config form)
  app/                     the controller
    control.py             the control law — pure functions, no I/O
    maintenance.py         the monthly cycle state machine
    hass.py                Supervisor/Core API access
    store.py               persistent state in /data
    mqtt.py                optional status entities
    web.py                 ingress UI
    main.py                orchestration, heartbeat, failsafe behaviour
  test_control.py          runnable checks — no framework needed
  test_maintenance.py      runnable checks — walks a full cycle in fake time
  DOCS.md                  the add-on's documentation tab
firmware/goodwe-master.yaml  ESPHome config for the T-CAN485
estop/rs485_log.py           optional RS485 e-stop / bus witness
docs/GoodWe-RS485-Field-Guide.pdf  the guide techs carry (10pp, A4)
docs/build_guide.py          its single source - rebuilds the HTML and PDF
FIELD-GUIDE.md             how to edit and rebuild the guide

Install

Settings → Add-ons → Add-on store → ⋮ → Repositories → add this repository's URL, then install GoodWe RS485 Controller.

Requires Home Assistant OS or Supervised. Add-ons cannot be installed on HA Container or Core.

Read this first

The inverter holds its last command forever. It has no meter-timeout of its own — a controller that dies mid-command leaves the battery running until a human intervenes. Measured on real hardware: 5 kW of discharge held for 113 seconds after a controller went silent.

Three layers exist because of that, and only the third covers the Home Assistant machine itself dying:

  1. ESP32 watchdog — no fresh setpoint for ~30 s → command 0 W, and keep commanding it.
  2. Wind-down before firmware updates — 0 W written before the update starts.
  3. RS485 e-stop (optional) — writes 0 W after 30 s of total bus silence.

Sites sold without the e-stop must have the acknowledgement in FIELD-GUIDE.md §10 signed.

Development

The control law and the maintenance machine are pure Python with no Home Assistant imports, so they run anywhere:

cd goodwe_controller
python3 test_control.py
python3 test_maintenance.py

Both must pass before shipping any change. They are not unit-test theatre — each assertion corresponds to a rule whose absence produced an observed failure on real hardware, and the comments in control.py say which.

Compatibility

  • GoodWe ES / BP family inverters (AA55 / RS485 meter-bus generation)
  • The protocol is reverse-engineered. There is no vendor contract, and a firmware change on GoodWe's side could break every installation at once. Say so when you sell it.