Claude
c81289527f
`run_tariff_refresh()` promised in its own docstring that "a failure does not clear the plan", and enforced it with `except Exception` - a branch a supplier outage never reaches. `load_prices()` states the reason in its own words: it "RETURNS, NEVER RAISES, for every failure a site can actually have", because a degradation arriving as a traceback into the planning tick would stop the controller regulating over an expired certificate. So a dead feed RETURNS a §11.4 plan, the `try` succeeds, and the assignment below it overwrote the good plan unconditionally. With `static_profile` unset - the shipped default, and the normal state of a dynamic-tariff site - `_degrade()` returns `TariffPlan(no_data, None, "none")`: a complete 48-hour plan replaced by nothing, at the FIRST failed fetch, ~27 minutes after the last good one. `TARIFF_MAX_AGE_S` (5400 s) never governed anything and there was no serve-stale window at all. Fourth card in one family: FCST-04's M4 (`not ok` only), FCST-05's HIGH (`(JSONDecodeError, OSError)` only), FCST-06 (`not self.ok` only), and now `except Exception` only, for a path that never raises. The question is now asked once, after the attempt, from the evidence that exists - FCST-06's answer, one module over. The evidence is `TariffPlan.from_feed` (did this resolution observe the configured feed) and the shipped `fresh_tariff_plan()`, reused rather than transcribed. A degradation replaces a standing observation only once that observation has aged out, so `TARIFF_MAX_AGE_S` is now the serve-stale window it reads like. A §11.4 static fallback does not replace a fresh provider plan either, although it carries real prices: every point `_degrade()` builds is `provisional=True`, so `firm_points()` is empty, `arbitrage()` refuses and `cheap_now()` is False - everything a consumer may act on is already off - while a day-ahead price for a given hour does not change once published. The rule is deliberately not symmetrical: a standing plan that is itself a degradation IS replaced, or an outage would freeze the operator's static profile at the window it was first generated for. `tariff_at` does not move on a kept plan. It is the moment of the fetch that produced the plan standing, `fresh_tariff_plan()` judges the age from it, and an unmoved timestamp is the only thing that tells a kept plan from a freshly fetched one. test_arbitrage.py section 8b drives the whole chain with nothing stubbed but the socket: the transport raises the way aiohttp does, load_prices() returns no_data, _degrade() builds the §11.4 plan, and the shipped run_tariff_refresh() decides. A check that patched resolve_tariff to RAISE would have passed against the defect. Ten mutations, ten reds, no survivors; 29/29 suites green. Out of scope and unchanged: the persisted price store still does not back the plan during an outage (FCST-03), and the status banner and the Arbitrage row's lag are separately carded. 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.