glenn schrooyenandClaude Opus 5
616b62d3e9
TARIFF-01 measured the quarter and said the consumer would be this card. It is
one new module, app/peakguard.py, and one new claim.
THE MECHANISM. Every cycle the guard projects the open 900 s block to its
end-of-interval average - from P1 telegrams only, never from the command - and
compares it to a ceiling. Over the ceiling it files ONE arbiter claim: a lower
bound on the setpoint at P_PEAK. That single shape is both behaviours 10.1 asks
for, a hard clamp on charging and pre-emptive discharge, and it cannot cap
discharge or export, because a floor cannot. 9.1's asymmetry becomes a property
of the object instead of a rule to remember.
excess = 900 x (projected - ceiling) / seconds remaining
floor = MEASURED battery power + excess
The 900/remaining gain is 1.0 at the top of the quarter and grows, so the guard
is gentlest where its projection rests on the least evidence. The floor is sized
from delivered battery power, not the standing command: a floor built on intent
re-adds its own unmet ask every cycle and winds to the rail whenever the inverter
fails to follow, and test_peakguard.py part 1 shows the two diverging.
IT TRIPS, AND THE CAPTURES DECIDED THAT. On the healthy reference day it engages
on zero of 95 quarters. The action is level-triggered, unlatched and re-derived
every cycle, so a false engagement costs one cycle of discharge rather than a
parked battery - the cost SAFETY-18 could not bound and this one can. Replayed on
2026-08-20 the billed quarter goes from 5029.8 W, above the inverter's own 5000 W
rating, to 3485 W, under the soft limit and without saturating. Quarters under
the limit across both committed days: 189/190 -> 190/190. Two days is not thirty
and AC 3 remains TARIFF-01's open item.
BLINDNESS IS CHECKED BEFORE THE PROJECTION IS GRADED, and it is a different
action. A fresh averager projects a confident 0 W, which is under every ceiling
there is; a meter gap longer than meter_max_age_s makes the projection read LOW;
a frozen meter reading export projects 0 W at full coverage. All three become a
floor of 0 W - no importing while the billed quantity is unobservable - which is
one-directional and cannot cost pack energy. That is the backstop SAFETY-18 could
not be: its alarm arrives at 300 s of a 900 s quarter and commands nothing. The
frozen term is freeze.looks_frozen() itself, on this cycle's standing command.
THE CEILING IS peak_cap_w, RAISED ONLY BY AN OBSERVED READING. NO_RECORD and
NOT_OBSERVED both leave it at the cap, so an unreadable peak store makes the
guard stricter and never looser. The gate is the reading's STATE, not whether a
number happens to be attached: today a `peak_w is not None` test behaves
identically, and depending on that coincidence is how a future last-known-peak
field would raise the ceiling off a read that failed. headroom_w() is
deliberately not consumed - cap minus peak turns a zero peak into FULL freedom.
TWO DEFECTS FOUND BUILDING IT, both in the interaction rather than the
arithmetic, and both caught by running the thing rather than by reading it:
* A LIMIT does not out-vote another LIMIT. arbiter.resolve() applies every
limit at or above the winner's priority and takes the most restrictive, so
the peak floor (lo >= 0) and the maintenance charge-only shaping (hi <= 0)
resolved to a CONTRADICTION and 0 W - the battery parked in the exact quarter
it should shave. Fixed by suppression, not priority: main.py drops the
maintenance shaping while the guard is engaged, which is what that branch
already did for the optional peak_forecast_entity - a key empty on a default
install, so until now the suspension could not fire on the site that needed
it.
* Thresholding `excess > 0` released the claim the instant it began working,
producing seventeen engage/release cycles in one 900 s quarter and leaving
that quarter 49 W over the limit it had spent fifteen minutes holding. That
is 10.2's oscillation. The threshold is now the floor itself, which is the
same arithmetic read as a level rather than as a switch.
PeakTracker.project() no longer reads a private name with a default.
getattr(averager, "_last_net", 0.0) failed quiet AND disarming - a rename credits
0 W held, the projection reads low, the money guard does not engage.
QuarterAverager.held_net_w is a documented public property now, read without a
default, and Projection carries it. TEST-13 item 4.
NO NEW OPTION AND NO FOURTH DEFAULTS SITE. The ceiling is peak_cap_w, the
coverage threshold is meter_max_age_s, the freeze predicate is meter_freeze_s,
and the achievable discharge comes from max_w and the device rating. config.yaml
and validate.py are untouched; 14's capacity_peak_limit_kw stays declined. On
meter_source: off there are no telegrams, so the guard does not run at all and
the status page says NOT COVERED - running it there blinded it permanently and
stopped every legacy install from charging, which is what the first cut did until
test_clamp.py's export case caught it.
test_peakguard.py: eight parts, all figures derived from the shipped config.yaml
and the committed captures. Part 8 runs seven one-line defeats of the guard and
reports which check bites; six do, and the seventh is reported as NOT caught,
because max(cap, peak) makes a zero peak the strictest ceiling there is and there
is nothing left to catch.
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.