adminandClaude Opus 5 f9e7fbf86d SAFETY-32: bms_soc_floor per pack, rule 8 per unit
`bms_soc_floor` describes A BATTERY, not a site. At two packs of different
models the cut-outs differ, and one number for both graded the shallower pack
against the deeper one's BMS - so a site with cut-outs of 10 % and 30 % under
`peak_soc_floor: 20` STARTED, and the guard would command a forced discharge
that pack B's BMS, not the operator's floor, is the thing that stops. That is
rule 8's own failure mode, reached through rule 8.

Scoped to the card's third bullet, per its PM PROOFREAD: the aggregate
anti-windup (DEV-02) and per-instance `achievable_w` (CFG-04) were verified as
already shipped and are untouched.

* config.yaml: `bms_soc_floor: int(0,50)` REQUIRED per `inverters:` entry.
  Nothing is inherited; the flat key stays the single-inverter shape's own
  cut-out. A per-entry DEFAULT was declined - a default is one number for every
  pack, which is this card's defect - and the decision is recorded.
* inverter.py: `Inverter.bms_soc_floor`; an entry that states none gets None,
  not a borrowed number and not 0.0 (the most permissive value the key has).
* peakguard.py: `Pack`, `pack_floor_pct()`, `pack_permissions()`,
  `binding_soc_floor()`. `discharge_permitted()` is unchanged and is still the
  one place the question is answered.
* validate.py: `unit_bms_floors_indexed()` carries the ROSTER index; rule 8
  grades EVERY unit and NAMES the one it refuses. Graded with the offender
  SECOND and with the same two numbers in the other order.
* main.py: `Controller.packs`; `decide(soc_floor=...)` is the per-pack
  reduction of the same option; the floor-limited notification names the pack
  that stopped the site. `pack_floor_soc` - the emptiest pack, and its
  None-on-missing behaviour - is untouched.
* tools/supervisor_shape_probe.py: RE-RUN and repaired. The required key broke
  §C and left §D printing PASS on a refusal about a different key. §D is now an
  isolated counterfactual over an accepted merged baseline, one key varied,
  asserting the key name. `all cases passed` on 2026.08.0.

Stated rather than hidden: under any config rule 8 accepts the per-pack FLOOR
reduces to `peak_soc_floor` for every pack. The reduction is written for
`unit_caps_indexed()`'s reason and graded on both sides - 1775 rule-8-valid
pairs answer the option, the pair rule 8 refuses answers the cut-out.
`peak_soc_floor` is still one number for the site, so the "deeper pack
needlessly withheld" half is filed as an open question, not closed.

Full 19-file suite green. Twelve source mutations through
tools/mutation_run.sh: eleven red, one argued survivor. The battery also found
`_flat_bms_floor()` defaulting in two places, each covering for the other.

No measurement of inverter B appears anywhere: it does not exist yet. Every
second-pack figure is simulated and labelled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
2026-09-05 03:01:57 +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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