glenn schrooyenandClaude Opus 5
3527c8a04c
Review found the case I asked it to construct, and it is not a corner case. The rate limit alone DELAYS A RUNAWAY: a benign one-cycle clamp that spends the budget, then a continuous §10.3-shaped runaway, held the runaway's first notification for up to 140 s - one REASSERT_S minus a cycle. On the live install, where ordinary railing spends the budget essentially all the time, a runaway arriving during normal operation would be delayed with near-certainty. That is the "benign noise suppresses the bug signal" shape this module's docstring is written against, and the family the first attempt at this card died of. THE ESCALATION. An episode that has not yet spoken because an EARLIER, unrelated episode spent the budget speaks anyway once it has engaged SUSTAINED_CYCLES = 3 times in a row. The discriminator is run length and the two populations genuinely differ: the live flood was runs of length ONE (engage, de-assert, engage), while a runaway engages every cycle. Measured, and it costs nothing it was protecting: live scatter flood (305 cycles, 1-in-6) 11 -> 11 notifications chatter 1-engaged/3-clean over 8000 s 50 -> 50 notifications pinned 900 s quarter (floor is 5) 6 -> 6 alarms runaway delay after a benign episode 140 s -> 10 s ⚠️ MY COUNTERFACTUAL CHECK COULD NOT FAIL FOR THE DEFECT IT NAMED, and review caught that too. It read `ClampWatchdog().note(True, ...) is True` - a FRESH object, which only exercises the `last_alarm is None` branch, the trivially-true one. A fresh watchdog has no earlier episode to be held back BY. It now SPENDS THE BUDGET FIRST: benign clamp, gap past CLEAR_CYCLES, then a continuous runaway, and asserts the delay is well under REASSERT_S. That is the third instance in this file of the family recorded at line 216 and at the 224 s sweep, and it was guarding the most safety-critical property in the change. Also pinned: `last_alarm` SURVIVING the de-assert. Review built the mutation - if the de-assert also refreshed it, chatter collapses from 50 notifications to 1 and the alarm never fires again, with the suite green. That is the "alarm that never fires" class, a different bug from one that fires later. Now caught. Both new checks verified against the mutations they name: removing the escalation -> 1 FAILED; refreshing last_alarm on de-assert -> 1 FAILED. Full suite: 21 passed, 0 failed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
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
MUTATION.md how to run a mutation so the result means something
tools/mutation_run.sh the mutation harness - purges bytecode, then grades
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. To prove a check bites - the way
almost every claim in this repository was established - mutate the module and
run tools/mutation_run.sh, which clears __pycache__ first. It is not
optional: a same-size edit reverted inside one second leaves CPython reusing the
old bytecode, and the run grades code that is not there. goodwe_controller/MUTATION.md
has the mechanism, the measurement, and what the flags do not do. 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.