price_taxes_eur_kwh shipped at 0.06 against a real Flemish 0.11736 - Fluvius Antwerpen 5,35 + bijzondere accijns 4,876 + groene stroom/WKK 1,51 + energiebijdrage 0, incl. 6% VAT, from the Eneco residential card for September 2026. Across the eight Fluvius DSOs the range is 0.117-0.131, so the shipped default was roughly half. The components ship as rows in the code, and the exact unrounded sum is used so the check asserts an EQUALITY against them rather than a tolerance. The energiebijdrage is a ZERO ROW, not an absence - it went to 0 EUR/MWh on 2026-08-01 and was merged into the excise, so anyone hand-computing this from an older guide double-counts it; deleting the row changes no sum, so its PRESENCE is graded separately. AN UPGRADE HAZARD THE TICKET DID NOT NAME, found and closed. App.options is a deepmerge of config.yaml's defaults over the stored options, so the moment the default moves, every site STORING 0.06 becomes non-default with nobody having edited anything. Combined with TARIFF-17's new rung - a taxes period table beside a non-default scalar is a startup refusal - a working Walloon or Brussels site with a table would have hit SystemExit(78) on the upgrade, over an inert number the table overrides anyway. Closed with SUPERSEDED_TAXES_DEFAULTS_EUR_KWH: validate.py reads a superseded default as untouched too. The rung is NOT weakened - a genuinely custom 0.1198 beside a table is still refused by name, and the refusal now names both figures. AND THE TICKET'S FRAMING WAS WRONG. I wrote that a site which took the default silently gets a different number. That is not what the deepmerge does: an existing install keeps its stored 0.06 and sees nothing change. The new default reaches a FRESH install, and an existing one only when its options are re-saved. Said plainly in the CHANGELOG, flagged as not re-measured on this branch (the 70-of-71-keys figure is 0.9.0's), with predeploy_check.py --options named as what would confirm it. THE FIGURE IS THE BOTTOM OF THE BAND, DELIBERATELY, and the argument is the agent's rather than the ticket's: the error directions are not symmetric. Set too high, a genuinely negative hour reads positive and the add-on exports into paid disposal - section 17's own regression case. Set too low, it only declines a trade that would have paid. One default standing in for eight DSOs belongs at the bottom, and Antwerpen's 0.11736 is a real card row there rather than a synthesised minimum. A CHECK HAD TO BE REWRITTEN RATHER THAN RE-POINTED. test_price.py section 0 justified its own constants by '0.06 is exactly twice 0.03'. This card ends that coincidence, so the sentence is false and is gone; it now asserts per figure that neither shipped default equals the fixture, which is stronger than the tuple compare it replaced. Recorded rather than quietly dropped, along with three other now-false claims the change created in test_price.py's docstring, MUTATION.md and DECISIONS/TARIFF-15 - which had predicted this card and is annotated as shipped. Evidence: baseline 29/29 before any edit, 29/29 on the committed tree. Ten mutations, all red, every revert sha256-verified and every grade taken in a container with the tree :ro so no .pyc can exist. Two are zero-byte. The interesting one moves the component rows AND the default AND config.yaml together into a coherent West-Vlaanderen card - caught only by the literal typed in the test file and the band check, which is why the sum is graded from two independent sides. What the suite cannot see is stated in the PR: it grades the default against the card as a number, never the card against Belgium.
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.