glenn schrooyenandClaude Opus 5
4bd659c499
T-1, and it was a fleet-wide trip to zero. publish() emitted p1_age unconditionally, and published_age_s counts from P1Ingest.__init__ when no sample has ever arrived. With meter_source defaulting to off, every existing install would have published sensor.p1_sample_age_s climbing without bound; the ESP32 does `has_state() && state >= max_age_s` and forces the layer-1 failsafe, so each of them would have pinned its inverter at 0 W within 30 s. Exactly the opposite of the zero-regression the off default was for. The key is now omitted from the payload AND from MQTT discovery when P1 is off, so the entity does not exist at all - which is the status quo, and what has_state() is testing for. The predicate is one function, is_enabled(), because the grid reading, the task start and the discovery announcement have to agree or this comes back. T-2, connect no longer manufactures a sample. get_states returns whatever HA currently holds, which after a Core restart is a RestoreEntity value of unknown age; stamping it with ingest_ts=now reset the age and reported a fresh meter that could have been dead for an hour. run()'s own docstring already said a reconnect must emit nothing - the code disagreed with it, and a test asserted the violation. The cache is still primed, so the first real state_changed builds a complete sample; the age just stays honest until one arrives. T-3, gaps are no longer filled with the last held value. The averager held a sample forward across any interval, so a meter dying at 5 kW and returning ten minutes later credited 5 kW x 600 s to the capacity-tariff accumulator - a fabricated peak on a permanent record. The hold is capped at max_age_s: past that the stretch is walked so block boundaries still land correctly, but nothing accumulates and elapsed does not grow, which is what finally makes the comment about a gap dragging the billed average down true. Same threshold for control and billing: a reading too old to steer by is too old to bill by. T-4, the out-of-order/duplicate guard is covered. It was untested, and the reason is worth recording: the obvious assertion passes without the guard, because the negative interval is separately refused by the covered > 0 test. What the guard prevents is the timestamp REWIND, which only shows up one sample later as a re-integrated window. The test now goes one sample later. T-6, DOCS was wrong about latency. meter_max_age_s and stale_input_s stack, so meter death to 0 W is 45 s and not 30. Documented as a table with both clocks. Also documented the T-5 asymmetry rather than papering over it: the age measures arrival, not change, so a stuck MQTT bridge republishing its last telegram still looks fresh. Correct on ha_dsmr, not detectable on mqtt_p1 without a change-detector. Written up as a known limit. Writing the T-1 test caught a second defect in the test itself: it recorded only MQTT topics, and object_id lives in the payload, so "the age sensor is not announced" had been passing for the wrong reason. test_p1.py: 99 -> 122 checks. 14 mutations run, all 14 red, files restored byte-identical - including one per fix above. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
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.