Four defects of one shape - the add-on's report of its own tariff plan was wrong, always in the direction that flattered it - and one check, which is the deliverable. 1. `TariffPlan.words` counted POINTS and called them HOURS. The live add-on logged `dynamic_dayahead from generic_dayahead, 132 h` for 132 quarter-hourly points = 33 hours. Belgium moved to a 15-minute MTU on 2025-10-01, so this was wrong every time it was printed, and NOT by a constant factor: a 40-hour soak measured 1.79x .. 5.33x, because §8.3's carried points are hourly while the firm ones are quarter-hourly. `words` now reports both quantities, plus the firm/carried split and the spacing, in FCST-04's *Price history* wording so the two rows can be compared. 2. §8.3's firm-pair refusal and the flat-tariff refusal did the same, and they reach an operator through `self.arb.explain()`. This is exactly the point<->hour conflation TARIFF-14 removed from `at()`, left standing in the prose. `price_forecast.py`'s §8.3 carry-forward log line carried the third instance - a carried-HOUR count over a POINT count - and DOCS quotes it verbatim, so it is corrected here too. 3. The plan reached no HTTP surface at all. `rows["Tariff"]` was `static_status()`'s 30 s-tick sentence and never saw the provider plan - it read 'no static profile' at all 802 soak samples on a site whose feed was answering. It now carries the plan's shape. ⚠️ The two sources are kept distinguishable: the plan half is stamped with its own age, measured from `tariff_at`, because it can be up to TARIFF_MAX_AGE_S (5400 s) old. FCST-04 pins that row to DOCS as a pair; DOCS moves in this commit. 4. `main.py`'s "if and only if" was false. `cycle()` returns at the input hold before `self.arb = None`, so an armed site read `off (arbitrage_enabled)` - naming an option that is on - and, after one completed cycle, showed a decision up to 15 s stale as a current one. The row now reads the OPTION and separates three facts; `cycle_at` and `arb_at` make "this cycle reached no decision" an observation. THE DELIVERABLE IS THE CHECK. All four survived 29 green suites because nothing graded the strings a human is shown. `test_price.py` section 12 renders through the shipped `status_payload()`, parses each number out of its OWN SLOT and compares it against a figure computed from the fixture's construction parameters - not from the property the row was built out of (habit 4), and not as a substring of a sentence the same file wrote (habit 14). The fixture set is four plan shapes and the check computes and prints the field pairs no fixture separates. The *Arbitrage* row's states are driven through real cycles with a sensor answering None and graded by INEQUALITY. No behaviour changed: no threshold, refusal rung, claim or setpoint moved. MUTATIONS: 16, no survivors, one at +0 B (the risky delta) and red. Two were found by the battery INSIDE THIS CARD'S OWN CHECK: a -190 B survivor whose fixture varied two things at once (habit 4), and a mutation whose red was a TRACEBACK in an f-string operand and therefore named nothing (FCST-06). Both closed; the table is on the PR. All 29 test files green. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
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:
- ESP32 watchdog — no fresh setpoint for ~30 s → command 0 W, and keep commanding it.
- Wind-down before firmware updates — 0 W written before the update starts.
- 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.