THE BLOCKER. At the `delinquent()` call site, `self.tuning.saturation_w` -> `250.0` (-19 B) was a survivor of all 23 suites. It is not an equivalent mutant: two copies of inverter A, B wedged, `saturation_w: 1800` (inside its own schema int(100,2000)) and a load of 1600 W put B's shortfall strictly between the literal and the configured value - head names nobody, the mutant names B. At the shipped 500 both name it, which is exactly why every fixture in part 4 was blind: their gaps are all above both thresholds. It matters beyond a mutation score. `delivery.py`'s MIN_W_IS_SATURATION_W note and the `delivery_hold_s` block in config.yaml both promise an operator, in shipped prose, that there is no fourth copy of a threshold to keep in step and no way for the two to drift - raise `saturation_w` and this check moves with you. A literal at the call site removes exactly that promise, silently, and the promise is why the design was chosen over a `delivery_w` key. ASKING THE SAME QUESTION OF EVERY OTHER NUMBER THIS CHECK READS FOUND A SECOND SURVIVOR OF ALL 23 SUITES: `bms_floor=inv.bms_soc_floor` -> `10.0` (-13 B), invisible because config.yaml's own example states 10 % and every fixture in this file used it. Two arms bracket it: a pack at 15 % against its own 25 % cut-out is cold and must stay unnamed (the literal names an empty pack), and a pack at 8 % against its own 5 % cut-out is wedged and must be named (the literal explains the fault away). One arm on each side leaves no constant at all. `delivery_hold_s` and `is_live()`'s window were ALREADY pinned - the fixtures had to move them to run - and `LINK_STALE_S` has no option behind it, so "pinned across a changed config" is not available for it and is not claimed. DECISIONS section 9 enumerates all of it with the deltas and which check kills which. Verified in the CI image, tree mounted :ro, `python3 -B`, `__pycache__` purged and counted before every run (TEST-15): R5 saturation_w -> 250.0 -19 B killed by part 4b(a) R6 bms_soc_floor -> 10.0 -13 B killed by part 4b(b), both arms R7 arm(self.delivery_cfg) -> DeliveryConfig() -1 B killed (already) R8 is_live(now) -> is_live(now, 3600.0) +8 B killed (already) R9 pack cut-out -> conjoined site floor +105 B killed twice head: 23/23 test files PASS, no bytecode written during the run. No shipped behaviour changes: the only edits to app/ are comments. 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.