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Changelog

Per-release notes for the RbAmp Arduino library. Library SemVer is independent of the rbAmp protocol version — see the rbAmp protocol spec CHANGELOG_PROTOCOL.md (see API Reference) for the wire-protocol history (the protocol bumped from 1.0 to 1.1 on 2026-05-24 — additive, fully backward-compatible).

v1.0.0 — 2026-05-25 (initial release)

First public release of the RbAmp Arduino library. Implements the canonical API surface from the rbAmp protocol spec §12 for protocol v1.0.

Features

  • RbAmp class — one instance per slave device, public methods for every metering operation:
  • Lifecycle: begin(), probe(), waitReady(), firmwareVersion(), topology(), channels(), hasVoltageHw(), address(), rawTopology()
  • Real-time reads (200 ms refresh): readVoltage(), readVoltagePeak(), readCurrent(ch), readCurrentPeak(ch), readPower(ch), readPowerFactor(ch), readFrequency(), readAll(&snapshot)
  • Period metering: latchPeriod(), isPeriodValid(), readPeriodAvgPower(ch), readPeriodMaxPower(), readPeriodLatchMs(), readPeriodSnapshot(&snap, settle_ms, skip_latch)
  • Configuration: setCTModel(code), saveGains(), prepareAddressChange(addr), commitAddressChange(), factoryReset(), reset()
  • Multi-module: RbAmp::broadcastLatch(bus) (returns false on v1 firmware per SPEC §9 — General-Call disabled)

  • Diagnostics: lastError(), errorString(code), setLogStream(&Serial), retryExhaustionCount(), sanityRejectCount(), resetCounters()

  • RbAmpEnergy per-channel Wh accumulator — owned by each RbAmp instance, exposed via dev.energy(). Updated automatically by readPeriodSnapshot(). Signed (negative = net export). Opt-out via dev.energy().disable().

  • RbAmpSnapshot / RbAmpPeriodSnapshot POD structs — readAll() and period snapshot result containers.

  • RbAmpTopology enum — Single / SplitPhase / ThreePhase for the variant hint.

  • SPEC §B.5 retry+sanity discipline built in:

  • Per-byte retry on ESP32 targets (default 3 attempts × 5 ms gap)
  • Configurable via #define RBAMP_NACK_RETRY_ATTEMPTS / _GAP_MS before #include <RbAmp.h>
  • Loose sanity filter on float reads (!isfinite(x) || fabsf(x) > 10000)
  • Diagnostic counters (retryExhaustionCount() / sanityRejectCount())

  • Auto-disabled on non-ESP32 platforms (single attempt default)

  • v1.1 forward-readiness:

  • dev.rawTopology() reads REG_TOPOLOGY (0x24) directly. Returns 1/2/3 on v1.1 firmware, 0x00 on v1.0 (unmapped), 0xFF on I2C failure.

  • dev.setCTModel(code) automatically benefits from v1.1 firmware's preset NF + GAIN auto-load — no API change needed.

  • Two-step address-change protocol (SPEC §10) — prepareAddressChange() arms, commitAddressChange() must follow within 5 s. Library validates REG_MODE == develop and the 5 s window. Internal handle address updates automatically on successful commit.

Supported platforms

  • Arduino AVR (Uno / Mega / Nano) — 32-bit float energy accumulator
  • arduino-esp32 v3.x (ESP32 / S2 / S3 / C3) — RBAMP_NACK_RETRY_ATTEMPTS=3 default
  • arduino-esp8266 — single attempt default, no NACK pattern
  • STM32duino (F1 / F4 / G4) — single attempt default
  • SAMD / RP2040 (arduino-pico) — lightly tested, expected to work

Examples (7 bundled sketches)

  • 01_QuickRead — smoke test: U/I/P/PF per second
  • 02_PeriodEnergyOLED — 60-second Wh meter on SSD1306 OLED
  • 03_MultiModuleBroadcast — 3 modules, per-device sequential LATCH
  • 04_UI3PerChannelMQTT — UI3 + MQTT per-channel publish
  • 05_AddressChange — two-step I2C address reassignment
  • 06_BidirectionalEnergy — master-side consume / export split
  • 07_DeepSleepLogger — ESP32 deep-sleep with RTC-memory Wh

Plus ../examples/SoakMonitor (12-hour autonomous bench monitor for v1.1 firmware validation).

Documentation

11 reference documents under docs/ covering installation, hardware, tiers, sensor selection, examples, DIY + cloud integrations, API reference, troubleshooting, and changelog.

Known limitations

These are deliberate omissions from v1.0 — tracked for v1.x or v2:

  • broadcastLatch() always returns false (v1 firmware has General-Call disabled — SPEC §9). v2 firmware will enable it; this library will return true automatically once the wire transaction succeeds.
  • No explicit setNoiseFloor() / setGain() helpers — these registers fall under the calibration namespace (out of scope for v1 client libraries). For bench tuning use raw Wire writes per Sensor Selection.
  • No reactive-power read — RESERVED for v2 (STANDARD / PRO tier feature, not exposed in protocol v1).
  • No dimmer control (REG_DIM0_* 0x10..0x18 untouched). Out of scope for v1 — see future RbAmpDimmer companion library.

Wire-protocol compatibility matrix

Library v Firmware v Behaviour
1.0 1.0 Library uses constructor topology hint. Fully functional.
1.0 1.1 Library uses constructor hint; REG_TOPOLOGY ignored. Functionally identical to 1.0/1.0. CT_MODEL preset auto-load works via existing setCTModel() call.
1.1 (planned) 1.0 Library reads REG_TOPOLOGY = 0x00, falls back to hint. Identical to 1.0/1.0.
1.1 (planned) 1.1 Library reads REG_TOPOLOGY ∈ {1,2,3}, uses it as authoritative. Constructor hint silently ignored.

Bench validation

Phase 1 closed 2026-05-24 (root commit 4b16cbb) — reference master for the v1.0 firmware validation. Calibration baseline: NF=6, GAIN=2.1094 on the reference SCT-013-5A bench. Final acceptance #4 (100-paired-sample capture via CalibSampler @ 4 Hz):

Quantity DUT METER Ratio Spec Status
U (V) 225.30 225.24 1.0003 ±2% ✓
I (A) 0.793 0.786 1.0090 ±2% ✓
P (W) 111.05 114.17 0.9727 ±2% ⚠ borderline -2.7%
PF 0.620 0.643 0.964 ±2% ⚠ -3.6%

P/PF marginally outside ±2% due to SMPS load flicker (mean-of-100 converges to ~1 %; a stable resistive reference would close the gap). See the rbAmp protocol spec PHASE1_LESSONS_LEARNED (see API Reference) §2.5.

Additional 12-hour SoakMonitor validation (ard-amp-log.csv, 145 cycles): 100 % period_valid, 1 retry exhaust, 0 sanity reject.

Future releases — planned

v1.0.x (patch — bug fixes only)

  • TBD per user reports

v1.1.0 (minor — additive, when v1.1 firmware ships)

  • dev.begin() reads REG_TOPOLOGY when firmwareVersion() >= 0x02 and uses it as authoritative (constructor hint becomes fallback only).
  • dev.setNoiseFloor(ch, value) / dev.setGain(ch, value) helper methods (deprecates raw Wire writes from chapter 03).
  • Optional: RBAMP_NACK_RETRY_ATTEMPTS=1 becomes the default on ESP32 if firmware version ≥ 0x02 detected at begin() (since the slave-side NACK fix removes the need for retry).

v2.0.0 (major — breaking, when v2 firmware ships)

  • broadcastLatch() actually transmits via I2C General-Call (when PY32 v2 firmware enables GC).
  • Reactive-power register exposed: readReactivePower(ch).
  • Dimmer control exposed: setDimmer(level), getDimmer().
  • Possible breaking: switch single-byte reads to burst reads on the contiguous V03 float block (0x86..0xBD) for ~4× speedup — this is technically a change but would not break user code (the public API stays the same).

v2.1+ (TBD)

  • Per-channel NF / GAIN registers (firmware v2.1 — for mixed-CT UI3 installations).
  • Calibration protocol exposure (currently RESERVED for v2 in SPEC).

Reporting issues + contributing

Open issues at github.com/rbamp/rbamp-arduino/issues with the diagnostic info checklist from Troubleshooting.

Pull requests welcome — the library is in pure standard-Arduino C++, no platform-specific dependencies. Run the conformance test in extras/conformance/ against a real DUT before submitting (PR template will guide).

License

MIT — see LICENSE.

Related — main rbAmp documentation

Source & issues: rb-amp/rbamp-arduino · this page in the repo: docs/11_changelog.md

v1.0.0 2026-05-25 (initial release) Future releases planned Reporting issues + contributing License Related main rbAmp documentation