glenn schrooyenandClaude Opus 5
8b51a51e20
TEL-01 shipped ha_dsmr and mqtt_p1, and neither can read the meter that is
actually fitted here. The house has a HomeWizard P1 exposing ONE signed
entity, sensor.p1_meter_active_power (+ import, - export); ha_dsmr wants two
unsigned registers and refuses a negative one outright, which is every
exporting telegram. So sensor.p1_sample_age_s could not be produced at this
site, and FW-01's watchdog needs it - measured, not theoretical: the house P1
went 51.1 s and 36.2 s without a state change overnight, both past
meter_max_age_s 30, so without the age sensor the watchdog would false-trip
the battery to 0 W.
Adds meter_source: ha_signed, reading p1_net_entity (and optionally
p1_phase_net_entities in L1..L3 order for the capacity-tariff peak). The
derivation is split_signed(), sitting next to make_sample's subtraction for
the same reason it does - the moment a user is asked to write two template
sensors that split a signed value, the sign convention is back in unreviewed
YAML underneath a safety input, which is exactly what TEL-01 removed.
The transport is a subclass of HaDsmrSource overriding only _wanted() and
build(), so every rule TEL-01 established is inherited rather than
re-implemented: ingest timestamping, meter_max_age_s, the clock-recomputed
sensor.p1_sample_age_s republished ~1 Hz, the plausibility ceiling, the
"prime the cache from get_states but never build a sample out of it" rule,
"a reconnect emits nothing", and unavailable/unknown treated as a MISSING
reading and never as 0 W.
Defaults to off. An existing install is unaffected until it opts in.
test_p1.py: 122 -> 174 checks. Includes an end-to-end run of the new
transport against a fake Home Assistant websocket, and the sign convention
asserted against real captured readings from
sim/scenarios/ha-p1_meter_active_power-2026-08-{20,23}.json (-5710 W at
13:46 local under full sun is export; +775 W at midnight is import).
Non-vacuity: ten mutations of the new rules, each applied alone and reverted
byte-identical. Nine turn the suite red. The tenth - splitting the per-phase
signed values rather than passing them through - is an equivalent mutant,
because make_sample subtracts the two lists again and does not sign-check
per-phase figures. That is recorded in a ponytail: comment at the site rather
than left for the next reviewer to rediscover.
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.