rbAmp modules — read AC energy over I²C, in physical units.

Read RMS voltage, current, signed power, PF and tariff energy over a 2-wire I²C bus — physical units, no master-side DSP. Up to 128 modules on one 2-wire bus. Bring your own controller — ESP32, Raspberry Pi or PLC.

ESPHome Arduino Python (Raspberry Pi) ESP-IDF

Choose a model ↓ Docs & libraries

Why rbAmp modules

One UART is never enough — go I²C

Most MCUs have a single UART, usually taken by the debug console; Arduino SoftwareSerial is flaky. rbAmp talks I²C: many modules on two shared pins, and your UART stays free.

Physical units — zero master-side math

The module does ADC/DSP/true-RMS at 5 kHz and returns ready float32 U/I/P/PF — not raw samples. No interrupts, no sine-catching, no DSP code on your MCU.

Atomic Wh latch → tariff-correct energy

One CMD_LATCH_PERIOD closes/opens a period with no read-reset gap; no dropped or double-counted samples. Energy computed master-side, matches utility intervals.

Open API + open libraries

Documented register/command map + native MIT libs (ESPHome / Arduino / ESP-IDF / Python). Any stack, or your own code.

Galvanically isolated — safe by design

Mains-side (HV) and signal-side (LV) are fully isolated: isolated voltage front-end + toroidal CT + isolated I²C. Safe for you and for your controller.

3.3 V logic, 5 V-tolerant — no level shifter

SDA/SCL/DataReady connect straight to ESP32 or Raspberry Pi GPIO. Power VCC at 5 V; on-board 3.3 V regulator handles the rest.

Available now — BASIC line

Bare-PCB modules - embed in your own enclosure. Buy the module alone, or the module + matching sensor as a bundle.

SCT-013 — clamp-on Clip-on, no power-down, 3.5 mm jack, sensor accuracy 1–3%.

SCT-013 Wattmeter — UI1 / UI2 / UI3 / UI5 / UI7

Flexible wattmeter for non-invasive retrofit (1–3 ch).

U+I+P+PF+freq+Wh · clip-on, no power-down · module ~0.5% + sensor 1–3%.

Module Module + Sensor

SCT-013 Ammeter — I1 / I2 / I3

Add current channels to your bus.

I_rms / I_peak per channel · module ~0.5% + sensor 1–3%.

Module Module + Sensor

CT-wired — precision, through-core Sensor accuracy 0.3–1%, plug-in screw terminals, sees loads from 50 W. One-time power-down at install.

CT-wired Wattmeter — UI1 / UI2 / UI3 / UI5 / UI7

Precision wattmeter for panels.

U+I+P+PF+freq+Wh · module ~0.5% + sensor 0.3–1% · loads from 50 W.

Module Module + Sensor

CT-wired Ammeter — A1 / A2 / A3

Multi-channel precision ammeter.

I_rms / I_peak per channel · module ~0.5% + sensor 0.3–1%.

Module Module + Sensor

Capabilities — what you get from module.

Physical units, no master-side processing.

Real-time data

refreshed every 200 ms

Full register map →

U_rms

RMS line voltage (V)

P_active

active power (W, signed)

PF

power factor

I_rms[ch]

RMS current per channel (A)

Q_reactive

reactive power (var, signed)

Frequency

mains (Hz)

Atomic period latch

tariff-correct Wh

Unlike software integration that drifts when your ESP32 reconnects to Wi-Fi, rbAmp's atomic latch guarantees zero-gap energy accounting trusted by utilities.

Full guide →

CMD_LATCH_PERIOD

closes + opens period

Every 200 ms sample

prev or next, never a gap

Mode

continuous (1-min / hourly / daily) OR event (contactor, EV session)

From wire to data in 3 steps

Ready open libraries for every platform — from wire to data in minutes.

Connect

Wire the module: 2-wire I²C to your controller + the current sensor.

Upload

Drop in the open library — a few lines (ESPHome / Arduino / ESP-IDF / Python).

Result

Read ready physical units: U / I / P / PF / Wh in your dashboard.

Browse all libraries →

Ready to move your energy monitoring to I²C? Start now.

Begin with the BASIC line — available today. Full docs and open libraries included.

Browse the Basic line Read the docs

rbAmp platform — development vector

The rbAmp measurement core is unified — I²C is the base today.

Standard line

In development

Headline edge: bidirectional (live signed power, export counted) + 8 independent atomic-period accumulators (per-channel tariff energy in one latch).

● Module accuracy ~0.3% (vs Basic ~0.5%)
● Noise floor <10 mA (standby-load tracking)
● Up to 8 current channels per module
● Per-channel phase compensation

● Diagnostic flags (CT_DISCONNECTED, SATURATION, U_OUT_OF_RANGE)
● Traceable factory calibration

Watch on GitHub

PRO line

Roadmap

Power-quality analyzer: THD / harmonics, sag-swell events, 4-quadrant signed energy, 3-phase, waveform capture.

Interfaces

Roadmap

RS-485 / Modbus and Wireless (ESP-NOW / BLE) arrive in later revisions, with the same integration logic — no change to your master-side code.

Tier	I²C	Wireless (ESP-NOW / BLE)	Modbus RS-485
Basic	✅ Available	— Roadmap	— Roadmap
Standard	◐ In development	— Roadmap	— Roadmap
PRO	— Roadmap	— Roadmap	— Roadmap

✅ available · ◐ in development · — roadmap

Follow the rbAmp platform.

Standard, PRO, Wireless and Modbus are on the way — subscribe to get development updates and launch news, first.