glenn schrooyenandClaude Opus 5 c7eb8c6b97 SAFETY-42: close two mutation gaps, and correct what makes N=1 inert
The battery is 12 mutations, one freshly copied tree each, purged, `:ro`,
`python3 -B`, byte deltas measured. First round: 9 red, 3 survivors. All three
are now accounted for and the ledger is in DECISIONS §8.

M5 - `share <= 0` relaxed to `share == 0`, +0 B - WAS A REAL GAP AND THE TWO
OBVIOUS CHECKS DID NOT CLOSE IT. `short_by(-2000, 0) is None` and
`short_by(-2000, -100) is None` both stayed GREEN under the mutant: for a charge
share that is UNDER-delivered `share - measured` is negative and the `gap > 0`
test answers None anyway, so neither input can separate the two spellings. The
one that can is a unit moving MORE than its charge share - -2000 W told,
-3000 W measured, `share - measured` = +1000 W - which the mutant reports as a
shortfall. It is not one; it is something else driving that pack, which is
SAFETY-30's and SAFETY-31's question. That input is now the check, and M5 is RED.
MUTATION.md's third failure mode in miniature: the assertion ran, the sentence
was true, and the data could not reach the failure it named.

M11 - `inv.is_live(now)[0]` replaced by a literal `True`, -15 B - was a WIRING
gap the pure checks structurally could not see. `account(live=False, ...)` was
graded as a FUNCTION; nothing graded that `cycle()` asks the question, because no
fixture had a unit whose writes were being rejected. Such a unit still has its
last ACCEPTED command standing on the wire (`write_setpoint` leaves `last_write`
alone on a rejected write) and still measures nothing, so it looks exactly like a
wedged one to every number this check reads - and reporting it would be the
second, louder alarm about a state the allocator has already handled and logged.
`test_delivery.py` part 6 now builds that unit, with `rejected_since` back-dated
past LINK_STALE_S because the fixture runs in two seconds and the timer is
test_inverter.py's to grade. M11 is RED.

M3 - `len(asked) < 2` relaxed to `< 1`, +0 B - IS STILL A SURVIVOR, and it is an
EQUIVALENT MUTANT. With one asked unit `unaccounted` is a subset of a one-element
set, so it is either empty (`not unaccounted` returns {}) or equal to `asked`
(`len(unaccounted) == len(asked)` returns {}); with zero asked units both
spellings return {} as well. No input separates them, so no check can.

⚠️ AND FINDING IT CORRECTED THE MODULE'S OWN PROSE, WHICH IS THE MORE USEFUL
HALF. `delinquent()`'s docstring claimed `len(asked) < 2` was what makes N=1
inert. It is not - the PROPER-SUBSET rule is, and that line is a fast path and a
signpost. A false attribution of the mechanism in the file's own prose is exactly
what this repository keeps finding, and a mutation that survives is how it
surfaced. The line stays, with the equivalence written down beside it the way
circulation.circulating_w() records its own max(0.0, ...).

Also recorded, rather than left implicit: `account()`'s `parked` branch is graded
as a function but its WIRING is not mutated on its own; part 6's reversed-unit
fixture exercises it end to end, which is weaker, and the ledger says so.

Baseline 23/23 green before and after. app/main.py is byte-identical to the
previous commit - both closures are a test and a comment.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
2026-09-06 19:25:45 +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
    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
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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