adminandClaude Opus 5
f000547518
THE DEFECT, in one line. `inv.sign_wd.evaluate(stood, self.grid, ...)` compared
the command THIS controller put on ONE actuator against what the WHOLE SITE is
exchanging with the network. At a roster of one those are two views of the same
thing - specs.md §6.2's identity - and that is what makes the check sound and
what earned it the best record in the safety table (NOTES.md: 93 % agreement
while healthy against 4 % during runaway, four observed episodes, zero false
positives). At two inverters they are not, and it fails in BOTH directions:
FALSE TRIP inverter A commanded -1500 W while the meter reads +1500 W is
evidence of nothing when inverter B is discharging 3000 W exactly
as told. Nothing is faulty and the highest-value check fires.
MISSED the converse, and it is worse. A unit commanded +1500 W and
MEASURED at -1500 W, beside a sibling at +1500 W, leaves P1
exactly where a healthy site leaves it. The summation destroys the
evidence and no threshold recovers it.
DEV-02 had already shipped the per-INSTANCE half - one SignWatchdog per
inverter, namespaced latch, a trip on B no longer latching A. What was left was
the COMPARISON, and it is two questions rather than one:
PER UNIT this unit's standing command against ITS OWN measured power
(`Inverter.batt`, holding register 0x0518, per-instance since
DEV-02). Conclusion: "the actuator I am driving is not doing what I
told it" - a fact about one device, so the remedy stays the per-unit
`failsafe` SET that arbiter.CLAIM_SCOPE has classified SCOPE_UNIT
from the day it was written. That entry read "the evidence is
site-wide and the remedy is not"; the first half is now simply true.
SITE the SUM of the standing commands against the meter, as a new
`sign_site` SET at P_SAFETY on the site actuator, latched under flat
`site_sign_tripped` / `site_sign_reason`. This is the 2026-08-20
fault day and NO per-unit check can see it, because every inverter
may be faithfully executing its share of a number that is itself
wrong. It stops every inverter and the banner names the site.
WHAT IT IS NOT, said here because two guards that overlap without saying so is
how a false-alarm generator gets built. It is not SAFETY-31: circulation.py
compares the units AGAINST EACH OTHER and catches them pushing power THROUGH
each other, which nets to zero at the meter and about which no single command is
evidence. This compares each unit against ITS OWN COMMAND. They overlap in
exactly one scenario - a unit reversing while its sibling pulls the other way -
and test_watchdog.py asserts on that fixture that both fire and what each
concludes. It is also not the saturation freeze, which is a MAGNITUDE test
(|command - measured| > 500 W) that shapes the loop and fires on a merely
saturated unit; this is a DIRECTION test that latches and parks one.
THE FOUR NUMBERS, RE-DERIVED AT TWO INVERTERS - one carried with a justification
and one refused. 1890 closed-loop runs on admin/goodwe's TEST-19 two-master rig
in which NOTHING is faulty, swept over the whole range config.yaml accepts for
`gain` and `slew_w`, across load reversals with write staggers and flapping
loads, and RUN AT BOTH ROSTERS so the N=1 arm is the control:
unit_sign_disagree_w 250 `saturation_w / 2`. The check gates on both sides,
opposed, so the smallest gap it can see is 500 W -
exactly where compute()'s own anti-windup test
already says the inverter is not following. It
cannot fire on a divergence the control law calls
ordinary tracking. Worst legitimate opposition at
250 W: 10.0 s; the curve is nearly flat, because a
unit's own power chases its own command.
unit_sign_disagree_s 85 8.5x that 10.0 s, 2.8x the firmware's own 30 s
link veto (inverter.LINK_STALE_S), under half the
180 s site hold.
site_sign_disagree_w 300 CARRIED. Its argument is the meter's noise floor
and the 15 W deadband; the roster touches neither,
and the campaign agrees - the gate opens in 994 of
1050 runs at two inverters and 955 of 1050 at one.
site_sign_disagree_s 325 NOT CARRIED, and this is the number the card
exists to not assume. The worst legitimate
crossing at 300 W is 110 s with one inverter and
215 s with TWO, because the command must travel a
rail that is the roster sum at a `slew_w` that is
not - reachable at gain 0.05, slew_w 50 and a
2.2 kW load reversal, all schema-legal. 180 s
would have shipped a false trip. 325 s is 1.51x
the measured worst, inside the 900 s billing
quarter and inside every episode of the fault day.
AT ONE INVERTER NOTHING CHANGES, and "nothing" is asserted rather than assumed.
The two questions are the same sentence there, so only the detector that shipped
is armed: same comparison against the meter, same 300 W / 180 s, same reason
string byte for byte, same namespaced latch and flat rollback mirror, same
`failsafe` claim, same banner, same single status row - and the site detector is
NEVER CALLED, counted on the object over twelve cycles.
VERIFIED BY BREAKING IT. Thirteen mutations on fresh per-mutation trees with no
__pycache__, mounted :ro, with the battery refusing to report at all unless the
baseline is green. Twelve red on the first pass. M4 - the site half armed at N=1
as well - SURVIVED, because the check read `disagree_since is None` and the unit
detector trips first, parks the inverter and leaves the site standing at 0 W:
the assertion ran, the sentence was true, and the data could not reach the
failure it named. Replaced with a call counter on the object; M4 is red now.
Recorded as a survivor in DECISIONS/SAFETY-30-per-unit-sign.md §5, with the
first battery's own RED BASELINE - a shared mutation directory read mid-copy -
discarded rather than reported.
RECORDED, NOT FIXED: the site comparison is defeated by a square-wave load whose
half period is about one control cycle, which holds it opposed for ~1000 s. The
N=1 control arm is what makes that interpretable - it is identical at the roster
this add-on ships, so it is a property of comparing a lagged command against a
meter and has nothing to do with the second inverter. It wants an alternation
test rather than a number, and a card of its own.
SAFETY-24's lo-only asymmetry proof re-run unchanged: 1296 combinations, 0
negative floors, `hi` +inf on every claim, every claim on the SITE actuator.
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.