glenn schrooyenandClaude Opus 5
504e8daac3
release/1.0 went red at 00:00 on 2026-09-01 on a commit nobody had touched. `Controller.checks()` read the capacity-tariff peak with `self.peak.peak()` - no argument - so tariff.py resolved the month from `datetime.now()`, while test_tariff.py section 10 banks its quarter at the fixed fixture 2026-08-30. From 1 September the page was correctly asked for September, correctly answered NO_RECORD, and the row read "no completed quarter recorded yet" - a string containing no "peak", which the section's own filter required. Four checks failed. ISOLATED BY MOVING ONLY THE CLOCK. Same commit, same shipped-deps image, libfaketime: green at 2026-08-30, four failures at 2026-09-01. Identical atf4914a1, 04292c4~1 and04292c4, so this is the calendar and not a regression. It has been latent since TARIFF-01 merged on 2026-08-30, and every PR that ever ran this suite ran it in August. THE PRODUCT IS RIGHT AND THE TEST WAS WRONG, so the live page is unchanged. Section 5 of this same file calls NO_RECORD "a normal state on the 1st of the month" and a capacity tariff is billed monthly, so a page showing the current month is correct. `checks()` now takes `when: datetime | None = None` and threads it into peak() and warning_frac() - the convention PeakStore.peak(), PeakTracker.peak(), headroom_w() and warning_frac() all already follow. The one production caller passes nothing and still means today. AND THE DEFECT IS NOW DETECTABLE RATHER THAN SEASONAL. Three checks: the same controller read at two different reference months must produce two different rows, which no clock can satisfy; the later month must read NO_RECORD and stay distinguishable from both an observed peak and an unreadable store; and checks() with no argument must still mean today. Verified by mutation - a checks() that drops `when` is red at every clock tried, where the old section went green in August. The first draft of these checks was itself wrong in the same way and reproduced the bug: it selected rows on "peak", which the NO_RECORD row does not contain, so it dropped the row and then graded its absence. They select on "quarter(s) banked" instead. Full suite green, 15 files, at the real clock and at faked clocks in 2026-08, 2026-12, 2027-02 and 2027-03. Left alone deliberately: only the UNREADABLE branch prefixes its row with "capacity-tariff peak:". The NO_RECORD row carries neither that phrase nor the word "peak". That asymmetry is what made the original filter brittle and what broke the first draft above; it is product text with other suites reading it, so it is reported rather than changed. Co-Authored-By: Claude Opus 5 (1M context) <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
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
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. 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.