glenn schrooyenandClaude Opus 5 22ca341459
checks / unit (pull_request) Successful in 6m55s
ARCH-02: assert the invariant, because a fixture cannot enumerate arrangements
Review approved and then attacked part 5b, the control that stands between B1's
defect and a green suite. It got through in three edits:

    A1  delete `END LEG`                        5b CATCHES it        2 FAIL
    A2  ...and reorder the legs                 5b BLIND             1 FAIL
    A3  ...and reword the closing summary       0 FAIL, "all checks passed"
                                                with a splitter that closed
                                                ZERO legs

⚠️ TWO OF THOSE THREE ARE ORDINARY REFACTORS - reordering report legs, rewording
a summary line - and neither reads as touching a safety check. 5b caught the
unclosed splitter only because the clean leg happened to be printed LAST, and
the backstop that saved A2 was a hardcoded transcription of the tool's own
sentence, so rewording that sentence blinded it too.

FIXED BY ASSERTING THE STRUCTURE RATHER THAN ADDING A FIXTURE: a leg may not
open while one is open, and every leg that opens must be explicitly closed.
Driven - deleting `END LEG` now fails on the FIRST edit, whatever the order or
the wording:

    AssertionError: leg 'SAME-STEP' opened while 'STAGED' was still open - the
    tool stopped closing its legs, and a splitter that never closes swallows the
    closing summary into the last leg.

All three attacks include that edit, so one assertion kills the class. Clean
tree unchanged: 28/28, all checks passed.

⭐ AND THE RULE IN MUTATION.md IS EXTENDED, because review's finding is the
general case of it. It said "a per-thing check that has never seen the things
DISAGREE is a total". Part 5b DOES make them disagree, every run, and was still
blind. So:

    ...AND ONE THAT HAS ONLY SEEN THEM DISAGREE IN ONE ARRANGEMENT IS A TOTAL
    OVER THAT ARRANGEMENT. When a fixture cannot enumerate the arrangements,
    assert the invariant they share.

Also recorded, NOT fixed, with the reason: the reference carries `entity_id
unique_id device` and grades all three, but never the discovery TOPIC. Review
measured `homeassistant/... -> ha/...` exiting 0 with no findings while every
announced entity dies. `discovery_payloads()` already returns the topic and
`announced_rows` discards it, so a fourth column closes it - but the prefix is
HA's fixed contract rather than a name this project chooses, so it is not what a
tidy-up rename reaches. Lower LIKELIHOOD than the N1 gap it resembles, not lower
consequence, and it stops being a note the day the topic becomes configurable.

Two stale figures corrected: the tool claimed five migration mutations where
there are nine, and pointed at a DOCS.md heading that does not exist (the real
one is "Before you commission inverter B", verified present at DOCS.md:1577).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
2026-09-08 15:01:55 +02:00

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 — routes only, status and configuration
    config_page.py         the configuration page's markup, style and script
    configui.py            its field model, built from the Supervisor's own
                           schema + translations — owns no key, label or rule
    selfconfig.py          reading and writing this add-on's own options,
                           with the validate-first / compare-and-swap gate
    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
  MUTATION.md              how to run a mutation so the result means something
  tools/mutation_run.sh    the mutation harness - purges bytecode, then grades
  tools/supervisor_selfapi_probe.py  what the Supervisor really permits and
                           returns, run against its own release image
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

Picking this up after a break? Read HANDOVER.md first — current state, what is known broken, and what to do next.

Install

Settings → Add-ons → Add-on store → ⋮ → Repositories → add

https://gittea.kammenstraatha.duckdns.org/admin/goodwe-addon

then install GoodWe RS485 Controller.

⚠️ The repository must be PUBLIC for this to work. Home Assistant clones it anonymously; against a private repo the store shows nothing and gives no useful error. If it must stay private, install locally instead: copy goodwe_controller/ into the machine's /addons/ folder, then ha store reload — it appears as a Local add-on.

⚠️ Bump version: in goodwe_controller/config.yaml for every change. Supervisor keys the built image by that version, so without a bump it silently reuses the old image and your fix appears not to work — on your bench and on every client's machine.

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. To prove a check bites - the way almost every claim in this repository was established - mutate the module and run tools/mutation_run.sh, which clears __pycache__ first. It is not optional: a same-size edit reverted inside one second leaves CPython reusing the old bytecode, and the run grades code that is not there. goodwe_controller/MUTATION.md has the mechanism, the measurement, and what the flags do not do. 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

Check the serial number, not the model name. Characters 6-8 of the serial are the platform tag:

tag platform verdict
ESU EMU ESA BPS BPU EMJ IJL 105 — ES/EM/BP, AA55-era meter bus supported
SPB SPN 745 — SBP G2 (GW…-SBP-20) no
ESN ESC 745 — ES G2 (GW…-ES-20) no
ETU EHU BTU … 205/745/753 — ET/EH/BT hybrids no
SDT DST MSU NSU … PV-only inverters — no battery to control no

A "-20" or "G2" suffix means a different platform with a different meter protocol. The tags come from the goodwe library's PLATFORM_105_MODELS, which is also what Home Assistant's own integration uses to pick a protocol.

  • 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.
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