glenn schrooyenandClaude Opus 5
ab6fbe2f9e
The product owner answered SAFETY-25's §1 on 2026-09-02: OPTION A. The BMS cut-out is the DELIBERATE and only backstop for demand-driven discharge on the grid-following loop, and Option B - a loop-side reserve floor - is DEFERRED rather than rejected. Option A is the shipped behaviour, so this is a recording, not a change. `app/` is touched in exactly two places and both are comments that claimed the question was still open (freeze.py's finding, peakguard.py's point 2). No setpoint, no claim, no option, no default moved. The 17-suite run is green on the same numbers as before. WHY DEFERRING IS THE SAFE DIRECTION. Option B's proof - bms_soc_floor < loop_soc_floor <= peak_soc_floor, run through the real arbiter in test_peakguard.py part 10d - has an unstated premise: the reserve predicate and discharge_permitted() read the SAME state of charge. With two packs they read different numbers. The reserve binds on the emptier pack and files hi = 0; the peak guard, reading the other pack or an average, files lo = excess > 0; lo > hi is arbiter clause 3 and the answer is 0 W - the battery parked in the billed quarter, which is the failure the memo itself marks fatal. And no config validator can catch it: it is a runtime divergence between two readings, not a config ordering, so CFG-01's shape of check passes on the exact tree that parks the battery. Option A's cost is energy; Option B's cost built too early is the one quarter of the month that sets the bill. THE REVISIT TRIGGER IS ALLOC-01, recorded in §0c. Under ARCH-01's host-side allocator the two claims stop sharing a list: the loop floor becomes a per-inverter `hi` consumed as an INTERVAL at stage A, while the peak floor stays a site `lo` at stage B. Different claim lists, different stages, structurally unable to cross - a stronger argument than the ordering rule, because it makes the crossing unreachable rather than harmless. That is the shape in which Option B becomes safe to build. WHAT HAS TO BE RE-EARNED AT N=2 is stated plainly in §0d rather than left for someone to discover. SAFETY-27 now names five floors across two packs, so "the SoC" stops being a scalar the config can bound. And part 10f - the pin that made SAFETY-25 mergeable - CANNOT EXPRESS TWO PACKS: its dynamic half is a scalar 0-100 % SoC sweep against a single-series capture, and a two-pack exposure lives in the DIFFERENCE between two readings, which that sweep visits at no resolution. Its static half, the AST scan pinning the eight claim sources, still bites at N=2; the dynamic half goes silent. Merging a two-pack reserve on 10f's current green would be merging on a check that cannot see the failure. The options analysis is kept intact on purpose - §1-§7 stand exactly as written, including §5's "(recommended)" on Option B and §6's recommendation, with a new §0 saying what was decided and §6 marked as answered. A memo that recorded the verdict and deleted the reasoning is the failure this DECISIONS/ directory exists to prevent. Part 10e's check moved with the memo: it used to pin the honest "Status: OPEN" line and now pins that the memo names the option, the date and the trigger AND still carries both options and the recommendation. The tripwire itself stays - a ninth claim source in Controller.cycle() still takes 10f red on the line it is written, and "deferred" is precisely the state in which someone builds Option B by accident. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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.