glenn schrooyenandClaude Opus 5
98109a9b91
A fourth meter_source, `homewizard_local`, polling a HomeWizard P1's own local API (GET /api/v1/data) instead of watching an HA entity. The point is the age sensor. sensor.p1_sample_age_s is FW-01's watchdog input, and on every transport we had it measured "time since the value CHANGED", not "time since the meter REPORTED". Home Assistant offers nothing better: a repeated reading emits no state_changed, advances last_reported on neither serialiser, and state_reported cannot be subscribed to at all. Measured twice - 70 s of a frozen meter on the ENV-01 rig, and ten repeated readings against the live house. Our own capture of this house's meter goes 42.2 s and 97.0 s between changes, both past the default meter_max_age_s of 30, so the age sensor would have commanded 0 W on a perfectly healthy meter. Here every HTTP response is an arrival. The meter answered, now, with its current reading; whether the number moved is not consulted. Five identical readings are five arrivals. Reuses TEL-01's pipeline rather than restructuring it: same split_signed sign convention as ha_signed, same make_sample, same ingest stamping, meter_max_age_s, clock-recomputed age, plausibility bounds and the §20 unsigned-decode rejection. A failed or timed-out poll submits nothing, so it is a missing reading - never 0 W - and does not reset the age. meter_poll_s (default 5 s, the meter's own rate) is checked against meter_max_age_s once at startup, like the ha_signed entity ids. ⚠️ An arrival stamp cannot see a FROZEN meter, and no arrival detector can - one answering 200 OK with a stale number is arriving. The local API does expose what HA never had (the total_power_*_kwh registers stop advancing) and the transport tracks it as `unchanged_s`, but it is deliberately not folded into the age and not thresholded: this controller regulates grid toward ~0 W, and at a converged -10 W the export register needs six minutes to move by its 1 Wh resolution while the power figure legitimately repeats. Thresholding that would rebuild the false-trip limit cycle at the exact operating point we aim for. test_p1.py 179 -> 236 checks. Still defaults to off. 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.