glenn schrooyenandClaude Opus 5 ad9c5772a4 TEL-04: a meter source for the meter this house actually has
TEL-01 shipped ha_dsmr and mqtt_p1. Neither fits the installed meter - a
HomeWizard P1 publishing one signed figure, where ha_dsmr requires two unsigned
registers and refuses negatives. So sensor.p1_sample_age_s could not be produced
here at all.

ha_signed is a subclass of HaDsmrSource overriding only _wanted() and build(),
so ingest timestamping, staleness, the clock-recomputed age, plausibility bounds
and unavailable-is-never-zero are inherited by construction rather than copied.
A reviewer traced every inherited member and confirmed nothing in the base
assumes two entities.

122 -> 179 checks. Sign convention asserted against real captures in
sim/scenarios/: -5710 W at 13:46 local under full sun, +775 W at midnight,
verified to the timestamp by two people independently.

WHAT THIS DOES NOT DO, documented in DOCS.md, the docstring and the CHANGELOG
rather than discovered later: the age it publishes measures time since the VALUE
CHANGED, not since the meter reported. Home Assistant exposes no arrival signal
for a repeated reading - proven on the rig against a frozen meter (no
state_changed, last_reported advancing on neither serialiser, state_reported
rejected outright) and confirmed independently against the live house, where ten
repeated values all left last_reported frozen. So this entity must NOT yet be
thresholded by the firmware watchdog. ha_dsmr has the same blind spot and
escapes only statistically, because a DSMR telegram moves several entities.

The fix is to read the meter's own API, where every response is an arrival.
That is TEL-05, and it is FW-01's real gate.

Two equivalent mutants are known and recorded: the per-phase split, documented
at the site, and the incomplete-phase-set guard, which is cosmetic - both paths
return False, one via an extra log line.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-25 18:00:42 +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
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. 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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