OPT-10 measured that this site's pack reaches 90 % SoC on 2 days of 16 and that
20.5 kWh of surplus left the site while the pack had room - 12.6 kWh of it with
the battery not charging at all - and could not say WHY, because PV production
is recorded NOWHERE. Three causes need three different fixes (no irradiance:
nothing to fix; a charge-power limit; the optimiser declining to charge, which
is the only software defect) and guessing between them is how an optimiser gets
tuned to solve a cloud problem. This card adds the channel. It does not do the
attribution.
AN HA ENTITY, NOT A REGISTER, AND THAT IS A PRODUCT DECISION. This add-on's
RS485 bus carries the BATTERY inverter it drives; a household's PV inverter is
normally a different box from a different vendor reporting into Home Assistant
through its own integration. `pv_entity` takes whatever `sensor.*` the site's
own PV integration provides, any brand HA can read.
POSITIVE IS PRODUCTION, AND THERE IS NO `pv_invert`. The convention is derived
rather than assumed: `meter_entity` is positive when IMPORTING and `batt_entity`
is positive when DISCHARGING (DOCS.md, Sources), both of which are "power
arriving at the house's AC bus", and production arrives there too. Those two
keys carry invert flags because they are BIPOLAR and are READ BY THE CONTROL
PATH - `inv.batt` feeds SAFETY-30's per-unit sign check and SAFETY-31's
circulating-power sensor, so a reversed sensor hands the site a plausible number
it acts on. Production is unipolar and is read by nothing: a reversed sensor
announces itself as -4 kW at noon in the very history this card creates, and a
flag would only let an installer hide it. No negative-value alarm either - a PV
inverter's own standby draw makes a small negative reading at night ordinary, so
any threshold would be a number nobody measured.
ABSENCE IS NEVER ZERO, AND "DROPPED" IS NOT ABSENT. `publish()` SKIPS a None,
which is right for `circulation` and exactly wrong here: a skipped row leaves
Home Assistant holding the last number forever and the recorder draws a FLAT
LINE through the outage, which is indistinguishable from a measurement and
manufactures the "there was no surplus" conclusion this card exists to TEST. So
the absence is published, with HA's own payload: `mqtt/const.py` declares
`PAYLOAD_NONE = "None"` and `mqtt/sensor.py` tests it BEFORE the numeric branch,
so the entity's state becomes `unknown` and the recorder stores a GAP. Read out
of home-assistant/core `dev` on 2026-09-24 and quoted at the constant.
`ABSENT_AS_UNKNOWN` is a one-key set and the suite asserts `circulation: None`
is STILL dropped.
THE UNIT IS READ OFF THE ENTITY. `mW`, `W`, `kW`, `MW`, `GW`, `TW` - HA's own
`UnitOfPower`, every factor an exact power of ten. A sensor with no unit, or a
unit outside that table, is REFUSED by name and the status page says which.
`read_inputs()`'s `abs(raw) < 50` kW-or-W guess is safe for a quarter-hour
demand forecast and is NOT safe here: 30 W of dusk is an ordinary reading and
that heuristic would publish it as 30 kW.
GENUINELY OPTIONAL, AND NOT A SECOND `price_now_entity`. validate.py does not
mention the key - it cannot conflict with anything, because nothing else reads
it. The MQTT row lives in a new `OPTIONAL_SENSORS` list whose `include` argument
DEFAULTS TO EMPTY, so every caller that has never heard of `pv_entity` -
test_mqtt.py's fixtures, tools/rehearse_roster.py, anything written next year -
announces exactly what it announced before. Unset: no state call at all, no
entity, no topic, no status row, no page row. Set and failing: a CAUTION
(`ok=False, warn=True`), never a `bad` row, so a telemetry channel can never put
a battery site into NOT READY.
IT MUST NOT BECOME A CONTROL INPUT, AND THAT IS GRADED TWICE. `test_pv.py`
part 6 drives 40 cycles of the real `cycle()` and asserts the commands are
bit-identical across unset / no reading / 0 W / 8 kW, with a COMPUTED census
(33 modules under app/) showing the material is mentioned in exactly three:
pv.py, main.py, mqtt.py. `tools/tel11_pv_trace.py` is the cross-tree half -
`safety56_behaviour_trace.py`'s pattern with a DIFFERENT control clause, because
this card's claim is that nothing differs rather than that only sentences do: it
REFUSES unless the two `app/` fingerprints differ and unless exactly one side
reacts to the option. Measured on 41 stimulus cells:
control release/1.0 unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
control TEL-11 unset 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
control TEL-11 set 846a10a5b89e321086d535825925721e2f791012e8405948d4fd38d3f9d0be5f
telemetry release/1.0 unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
telemetry TEL-11 unset a443a6ceaffe072b44bcd5f2ad946c1ed6c9e01b69e278eca631f7f4d7892164
telemetry TEL-11 set 4e6d1cb289a957223ad0205f732a6fec6110ce1f2032c98ad60694e67625274f
UNSET is byte-identical in BOTH documents, which is stronger than "the control
path is untouched": an install that does not set the option sees no change of
any kind, announcement and status rows included.
⚠️ AND THE CARD'S CENTRAL MUTATION WAS A SURVIVOR ON THE FIRST BATTERY.
`self.grid -= self.pv_w` in `read_inputs()` - +106 B, on disk, purged, genuinely
running - came back GREEN, because the fixture drove a 6 kW export over 12
cycles, which puts the loop AGAINST ITS RAIL: a command moving `slew_w` every
cycle produces the same ramp for -6000 W and for -14 000 W of apparent error.
MUTATION.md habit 23 with a saturated ACTUATOR in place of a coinciding value,
and it is in that file now as the habit's second instance. The fixture now
drives a 600 W import the loop SETTLES on, against a responsive meter, and asks
habit 23's own question as its own check: shift the METER by the same 8 kW and
confirm the commands really would have moved.
Evidence: 31/31 suites green in the CI image, checks.yml's exact command, purged
tree, `:ro`. Ten mutations, NO survivors, each on its own `cp -a` of the tree so
habit 18's revert hazard is closed by construction - table in
`DECISIONS/TEL-11-pv-production.md` §7 with byte deltas and sha256s.
⚠️ THIS IS A RUNTIME CHANGE BEHIND AN UNCHANGED VERSION, AND
`tools/predeploy_check.py` WILL REFUSE IT. `app/`, `config.yaml` and
`translations/` are all in its `RUNTIME` tuple and `config.yaml` still reads
0.10.1, so the gate reports a NO-OP deploy until a version is cut. That is PKG's
call and this card does not take it.
No CHANGELOG section: `test_version_gate.py` 11b refuses a newest `## ` heading
that is not config.yaml's `version:`, and opening one would mean taking that
same packaging decision. The operator account is in DOCS.md.
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 — 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
docs/RELEASE.md how a change reaches the battery - `master` is
protected, releases go via PR from `release/1.0`
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.