A 40-hour soak drove a restart and caught the capacity-tariff row asserting '0 quarter(s) banked' for a month in which 120 quarters had been measured. The peak and its attributed quarter persisted; the count did not. It is the count, not the peak, that tells an operator how much of the billing month the measurement actually covers - a peak of 365 W over 120 quarters and the same peak over 0 quarters are very different claims about the same number, and after a restart the page made the weaker claim while displaying the stronger one's value. Reproduced through a real Controller and P1Ingest with a real restart, never by reading code: 12 -> 0 with the store still holding 12 rows. Fixed durable rather than removed - the count is the useful half of the row. PeakStore.banked_count(month) queries quarter_blocks and `recorded` became a property over it. After the fix the printed count matches the store on both sides, 12 -> 13, and 13 is CORRECT: the restart's restore() banks the stale open block, which the old process-wide counter never saw. TWO DEFECTS THE TICKET DID NOT NAME, both closed by the same change: the count was never month-scoped, so a fresh October reported a quarter banked from September; and it missed blocks banked by restore(). An unreadable store now returns None and renders 'an unreadable number of quarter(s) banked' - rendering it as 0 was rejected because it reads as a real zero, which is TARIFF-01's own disarming-value argument applied to the coverage figure beside the peak. THE TICKET'S SECOND FINDING WAS FALSE AND THE AGENT DISPROVED IT. I wrote that ties at the same wattage are re-attributed to the most recent matching quarter. The upsert is strictly '>', so an exact tie never writes at all - six exactly-equal 365.0 W quarters re-attributed zero times. The soak's drift was a real new maximum below the row's whole-watt display resolution: 365.0000001 W is a new peak to the database and the same '365 W' to the reader. A plausible diagnosis, checked rather than implemented. Tie attribution is nevertheless decided deliberately - EARLIEST wins - on what the row is for rather than on money: wattage is what is billed, and an operator investigating one event needs a stable answer. It is also what recompute_month() already did, and the two readers genuinely diverged: fed newest-first, monthly_peak answered 09:45 and the recompute 09:00, breaking the invariant part 8 exists to prove. peak_w is untouched and SAFETY-07 reads identical watts. Evidence: 29/29 green. Eleven mutations, all red, purged before each with the fingerprint verified after every revert. One was a REAL SURVIVOR at -3 B: banked_count() has two None paths and the first battery reached only one, because a never-opened handle short-circuits before any SQL. Closed by dropping the table out from under an OPEN store, behind a precondition asserting the same call answered 4 first. main.py is untouched - the row picks the fix up unedited because `recorded` is now a property. The residual is named rather than hidden: `recorded` answers for now() while the peak follows checks(when=...). Production has exactly one call site, self.checks() with no argument, where both are the same month, so the live page is correct and durable; they part only under the suite's when= affordance, and that mismatch is strictly smaller than the process-wide counter it replaces. recorded_in(when) is shipped and the row's move onto it is one token.
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 — routes only, status and configuration
config_page.py the configuration page's markup, style and script
configui.py its field model, built from the Supervisor's own
schema + translations — owns no key, label or rule
selfconfig.py reading and writing this add-on's own options,
with the validate-first / compare-and-swap gate
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
tools/supervisor_selfapi_probe.py what the Supervisor really permits and
returns, run against its own release image
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.