`min(moved, i_w) if i_w > 0 else max(moved, i_w)` files i_w == 0.0 under
rising-only, so the first push toward charging from exactly zero was blocked
permanently - the S-1 deadlock again, mirrored in sign. main.py resets i_w to
exactly 0.0 on every stop and every reseed, so it is a normal state.
Zero is now handled explicitly and both directions are allowed: nothing is
wound, so "may not wind further" has no referent, and a first step from zero is
bounded by the gain, the output clamp and the slew limit like any other.
Measured before the fix, at i_w == 0.0 and frozen: 12 800 of 25 920 ticks held
the integrator and 8 304 of those changed the emitted command, worst case
abandoning a 2 kW charge into a 4 kW export. Note this is NOT the same as the
reported symptom: at prev_w == 0 the command holds at 0 W either way, because
the output freeze forbids starting a charge while saturated, and that rule is
release/1.0's and unchanged. There is now a test asserting it deliberately.
Tests. The durable part is a property rather than more points: over 13 041
frozen states the integrator may be held ONLY by a correction pushing it
further from zero on the side it already sits, and any other hold fails. Both
signs at exactly 0.0. Mirrors added everywhere the suite tested one direction
of two - freeze wind/unwind while charging, i_w=-100, the export-direction
runaway, the negative clamp and slew.
DOCS: the cycles-vs-seconds deviation is now written down as a deviation - the
"> 10 s" criterion is not met as literally written, a cycle is one CHANGED
meter reading, and there is no guaranteed wall-clock window.
test_control.py: 43 -> 55 checks, all passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
S-1. The frozen branch admitted a correction only if it shrank |i_w|. That is
unsatisfiable for BOTH signs of error whenever |correction| > 2*|i_w|, i.e.
whenever the integrator is near zero, so the loop stopped moving and the freeze
could never clear - it clears when the inverter tracks, and not tracking is
what saturation means. Measured: 0 W held into a 2 kW import indefinitely,
where release/1.0 recovers on the next cycle. Re-encoded as the same asymmetric
rule the output freeze has always used: may not wind further in the direction
it is already pushing, may fall, cross zero or reverse. Same interpretation,
an encoding that cannot deadlock.
S-2. integrator_max_w defaulted to 1.5x max_w, which ADDED windup: in
release/1.0 the accumulator was the post-clamp command and could never pass the
rail. Default is now "follow max_w" (config 0 = unset). Measured on the 4000 W
load-drop sim, first cycle after the drop: 1000 W at the new default, 1800 W at
3000. DOCS row inverted - the useful direction is below max_w, and the 14 768 W
anecdote is a vendor controller, not evidence about this code.
S-3. The claim that i_w=None preserved release/1.0 exactly was false, because
the S-1 gate ran regardless of seeding. It is true again, and now asserted
rather than asserted-about: 3024-case exhaustive comparison against a
transcription of the old law, over both freeze states, both signs and either
side of the deadband. Added the carried-i_w convergence/overshoot sim that the
shipped configuration was missing.
S-4. Cycles are distinct meter values, not seconds: cycle() runs only when the
meter reading changes, so the window has no wall-clock bound. Comment and DOCS
corrected; the stall is detection latency, not a windup hazard, because the
same condition stalls the whole loop.
test_control.py: 33 -> 41 checks, all passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
The loop was in velocity form: the accumulator WAS the commanded power, so
"clamp the integrator" and "clamp the output" were the same line of code and
could not be set apart. This makes the accumulator an explicit carried value
(`i_w`), bounds it with its own `integrator_max_w`, and keeps the output clamp
where it was. Killing either mechanism now still leaves the other holding -
which is the point of the ticket, and what the new regression test asserts.
Freeze semantics: while saturated the integrator may unwind but not wind
further. A strict freeze would strand the command at whatever it reached,
because the condition that releases it is the inverter tracking again, and not
tracking is exactly what saturation means.
The integrator is re-seeded from the arbiter's actual output whenever the loop
did not get what it asked for, so entering any failsafe (all of which resolve
to 0 W) zeroes it, and the first cycle after release does not dump the stale
period as power.
test_control.py: 24 -> 33 checks, all passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
The deadband is a one-way ratchet: any resting point inside it holds
indefinitely. Import and export are separate registers on the meter, so a
loop resting at +14 W bills 0.34 kWh/day while behaving perfectly.
target_grid_w (default -10 W) moves that residue onto the export register.
Worst billed rest point drops from 15 W to under 5 W. Behaviour is unchanged
at target_grid_w: 0.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Turns the reference RS485 controller into something a technician can install
at a client site: a typed config form instead of YAML, an ingress UI that
names misconfiguration in words, and persistent state that cannot be broken by
a timezone.
Why an add-on rather than YAML packages or blueprints:
- Blueprints cannot create helpers, and the maintenance cycle is a state
machine whose phase and completion date must survive restarts.
- YAML packages need filesystem access, a configuration.yaml edit and a
restart - none of which belong in a client install.
- Add-ons authenticate with SUPERVISOR_TOKEN, so there is no long-lived token
to generate, store or leak on someone else's machine.
- Requires HA OS/Supervised. Container and Core installs cannot run add-ons at
all, which is a market decision, not an oversight.
The control law and the maintenance machine are pure functions with no Home
Assistant imports, and both ship with runnable checks (22 and 22 assertions).
Every assertion corresponds to a rule whose absence caused an observed failure
on hardware - the saturation duration term, the clamp-before-slew ordering, the
deadband, the sign convention.
One behaviour deliberately differs from the implementation it replaces: when
its inputs go missing this commands 0 W rather than replaying the last
setpoint. The reference version kept replaying, which the hardware watchdog
cannot catch - from the ESP32's side, Home Assistant is still talking to it.
Includes the ESPHome firmware (now parameterised: node name, inverter rating,
watchdog timeout) and the optional RS485 e-stop. FIELD-GUIDE.md carries the
commissioning gates, all judged on the wire rather than on how Home Assistant
looks, plus the written statement a site without an e-stop needs signed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016NckgXecasQb2eSsPYNSW6
adminandClaude Opus 5