goodwe-addon/HANDOVER.md

Handover — 2026-08-23

Start here. README.md is what the thing is; this is where it stands, what is known to be broken, and what to do next.

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1. State of the world

The add-on is controlling a real battery right now — the author's own house, a GoodWe GW5000S-BP.

running	local_goodwe_controller 0.4.0, boot: auto, holding grid at zero
installed as	a Local add-on: /addons/goodwe_controller on HA OS at 192.168.2.158
repo	Gitea admin/goodwe-addon (ssh://git@192.168.2.147:2222) — private
tuning	gain 0.6, max_w 5000, slew 1000, deadband 15, step 10, saturation 500/3, heartbeat 10 s
maintenance	disabled, and with no completion history — first cycle is "due" the moment it is enabled
e-stop	fitted at this site, Pi tap armed with --panic

The thing it replaced — a working Home Assistant YAML implementation — is parked at /config/packages_disabled_addon_migration/ on that machine. Rollback is: stop the add-on, move those four files back into /config/packages/, reload automations and helpers, switch input_boolean.goodwe_auto on.

⚠️ Never run both. They write the same setpoint. Two controllers on one actuator is the failure the whole design exists to prevent.

The research record — protocol, register map, why every tuning value is what it is, and a long "ruled out, do not re-investigate" list — lives in the other repo, Documents/goodwe, in NOTES.md. Read it before changing a constant.

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2. Deploying a change

# 1. edit under goodwe_controller/
# 2. BUMP version: in goodwe_controller/config.yaml        <-- not optional
scp -r goodwe_controller root@192.168.2.158:/addons/
ssh root@192.168.2.158 "ha store reload && ha addons update local_goodwe_controller"
ssh root@192.168.2.158 "ha addons logs local_goodwe_controller | tail -20"

⚠️ Supervisor keys the built image by version:. Without a bump it silently reuses the old image and your change appears not to work. This cost two rounds of "the fix doesn't work" in one evening. It applies to client updates too — a client only gets a change when the version increments.

Run the checks before deploying. No framework needed:

cd goodwe_controller
python3 test_control.py && python3 test_maintenance.py && python3 test_arbiter.py \
  && python3 test_validate.py && python3 test_p1.py && python3 test_watchdog.py \
  && python3 test_loop.py

⚠️ Mutating a module to prove a check bites? Read goodwe_controller/ MUTATION.md first, and run goodwe_controller/tools/mutation_run.sh. A same-size edit reverted inside one second changes neither the file size nor the whole-second mtime, so CPython reuses the bytecode it already compiled and the suite grades code that is not there - once already, reported as a survivor and disproved by disassembly (TEST-15). python3 -B does not save you: it stops bytecode being written, not a stale .pyc being read. The purge is the fix.

test_watchdog.py covers SAFETY-02's logic, its arming gate (derived from the real arbiter, not passed in), its trip path, and the fact that the latch survives an add-on restart. Its headline validation is not here at all: sim/replay_sign.py in the infra repo drives the same module over the two captured RS485 days and must fire on all four of the 2026-08-20 episodes and stay silent on 2026-08-23. That needs both checkouts:

GOODWE_ADDON_REPO=/path/to/goodwe-addon python3 sim/replay_sign.py
GOODWE_ADDON_REPO=/path/to/goodwe-addon python3 sim/replay_sign.py --stub

The second run checks the grader still discriminates rather than merely still passing — a watchdog that never trips and one that always trips must both be rejected.

⚠️ If you are testing the failsafe by hand, note that stopping and starting the add-on will not clear a trip. That is the point of it; use the Start / stop control button twice, or delete the trip from /data/state.json.

⚠️ DEV-02 renamed that key. There is one SignWatchdog per inverter, so the LIVE latch lives under unit/<inverter>/sign_tripped — unit/inverter-a/sign_tripped on a single-inverter site. That is the one to delete if you are clearing a trip by hand; deleting the flat one alone clears nothing.

⚠️ The flat sign_tripped is still maintained, though — it is the ROLLBACK VIEW, not a fossil. It is written alongside the namespaced key on a trip and cleared alongside it when you press Start / stop control, so an add-on you downgrade past this version still finds the latch it should. It is also read on every start, and the one disagreement it can produce is acted on: the flat key says tripped and no inverter came up latched means the latch was written by an older add-on while this install was rolled back — or the migration lost it — and the controller re-arms the latch and shouts in the log rather than coming up disarmed with a green banner. So if you edit /data/state.json by hand, clear both spellings or the next start will put the trip back.

⚠️ test_loop.py takes about 95 seconds (measured 93 s) and that is not a bug. It drives the real control loop, which sleeps 1 s a tick, eight times over, to prove a wall-clock property about it (SAFETY-12); mocking the clock there would leave the assertion testing the mock. The other six suites together are ~440 checks and finish in seconds — test_watchdog.py spends ~3 s of that driving a real Controller through a trip. If you shorten test_loop.py's windows, re-measure and correct this figure — an understated runtime is what makes a slow test look like a hung one, and a slow test that looks hung gets deleted.

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3. Known broken / unfinished

1. MQTT status entities are not adopted by Home Assistant. The add-on publishes correct discovery and live state — verified on the broker itself (goodwe_ctl/setpoint => 940.0). After the entities were deleted from the registry during development, HA would not re-adopt them, even after clearing the retained topics and reconnecting. Affects observability only; control is untouched. Try again after an HA restart, which is the cheapest next test.
2. The repository is private, so it cannot be used as an add-on repository URL — HA clones anonymously. Either make it public, or keep installing locally as at this site. Decide before the first client.
3. No real maintenance cycle has ever run. The mechanism is proven end-to-end in simulated time and partially on hardware, but a genuine low→full→hold cycle takes hours and has not happened. Do not decommission a client's vendor controller before one has.
4. The HA-side offline alarm is unproven. The Pi's 30 s panic write is the real cover; treat the HA alert as "within a few minutes".
5. Only platform 105 is supported — see §5.

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4. What to do next, in order

1. Peak shaving as a real strategy. This is why the arbiter exists, and it is now purely additive: a claim producer emitting Claim.set("peak", P_PEAK, …) from the quarter-hour forecast, plus a priority. Nothing existing needs to change — the maintenance charge-only limit already cannot bind it. Highest value per unit of work in a capacity-tariff market.
2. Run a full maintenance cycle at the reference site and record what it actually costs in energy and time.
3. Fleet health before more features. This system's signature failure is silent: an entity-id prefix killed two safety alarms for a day, a shebang made every call 401 while looking healthy. One site with the author watching found those. Twenty sites will not.
4. Decide the repository question (§3.2).

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5. The commercial question nobody has answered

A GoodWe "-20" / G2 inverter cannot be driven by this.

Platform comes from characters 6–8 of the serial number. Only ESU EMU ESA BPS BPU EMJ IJL — platform 105, the AA55-era generation — are supported. SBP G2 (SPB/SPN) and ES G2 (ESN/ESC) are platform 745, a different protocol. The reference unit is BPS.

That matters more than it first sounds: the SBP G2 is the model GoodWe currently sells to replace a GW5000S-BP. So today's product serves the installed base, not the base being installed. Everything above the firmware — control law, arbiter, maintenance, add-on, field guide — is protocol-agnostic and would carry over; only the register map is platform-specific.

Answering it is an afternoon: put the Pi tap passively on a G2 unit's meter bus with its vendor controller running, and capture. That either hands over the new register map or proves the approach does not transfer. Do this before building more features on top of a shrinking base.

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6. Things that will bite you

Each of these was found the expensive way. They are in the code comments too.

• run.sh must start #!/usr/bin/with-contenv sh. s6-overlay sanitises the environment, so a plain shebang means no SUPERVISOR_TOKEN and every HA call returns 401 — while homeassistant_api: true makes permissions look granted.
• A wrong entity id is not an error anywhere in HA. It just never produces a value, and the automation's own state still reads on.
• HA composes entity ids from the device area and device name. The same firmware yields sensor.goodwe_master_… at one site and sensor.cellar_goodwe_master_… at another.
• input_datetime states parse timezone-naive; subtracting now() raises and kills the whole automation before it records itself as triggered. Use the timestamp attribute.
• Alpine ships paho-mqtt 1.x, which has no CallbackAPIVersion, and musl has no aiohttp wheel — install from apk, not pip.
• A mutation run can grade code that is not there. CPython validates a .pyc on (source size, source mtime in whole seconds), so a same-size edit reverted within one second is invisible to it and the old bytecode runs. It manufactures survivors, never reds. Purge __pycache__ - tools/mutation_run.sh does - and see goodwe_controller/MUTATION.md.
• The inverter holds its last command forever. It has no meter-timeout. Every failsafe here exists because of that one fact, and anything in doubt commands 0 W rather than holding.