glenn schrooyenandClaude Opus 5
7aa1bd052e
A meter that answers 200 OK with a stale document forever is ARRIVING on every
poll, so every freshness mechanism in the stack reads it as healthy while the
loop integrates a constant error and rails: 360/135/75 s at the live install's
max_w: 5000 for a meter frozen at 350/1000/>=3000 W. Fifteen minutes of a 5 kW
unattended import sets the month's billed capaciteitstarief peak.
The detector is a conjunction, not the bare unchanged_s threshold TEL-05
measured and rejected:
unchanged_s >= meter_freeze_s AND |command| within 5 % of max_w
Both terms already existed and were already on the status page, and they fail
for independent reasons: at the converged point the command is nowhere near the
rail, and at the rail against a real load the kWh registers move in seconds. At
the shipped 300 s the relation is structural rather than a margin - the slowest
a healthy 1 Wh register can tick and still look unchanged is 12 W, which is
inside the 15 W deadband, so the command there is parked at 0 W.
Notification only, deliberately: an HA persistent notification with a fixed
notification_id, an ERROR log line, a UI event and a red status row. No claim,
no latch, no 0 W. A false trip parks the battery; a false notification costs an
alert. Only meter_source: homewizard_local is covered - the status page says
NOT COVERED elsewhere rather than pretending the guard is armed.
DOCS.md states the capacity-tariff exposure this does NOT close: peak_cap_w caps
maintenance charging and nothing caps the loop. That cap is SAFETY-07.
test_freeze.py grades both directions and was verified by breaking what it
watches (six mutations, all red): silent over the committed 40-minute converged
capture, silent over an hour of TEL-05's low-power case where the rejected bare
threshold is shown to fire, alarming on a genuinely frozen meter driven over
real HTTP through the real HomeWizardLocalSource (the rig's own hwsim freeze
fault when reachable), silent on the same railed command against a meter that is
still moving, and asserting on the service call that leaves Controller.cycle()
rather than on the watchdog's own flag.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015VXjA3LWccN1rJsk3okyPC
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.