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Sonoff Pow R2

Michael Ingraham edited this page Jun 3, 2019 · 4 revisions

⚠️️Special Attention ⚠️️

Do not connect AC power and the serial connection at the same time The GND connection of the Pow is connected to the live AC wire. Connecting serial with your PC will fry your PC and will electrocute you.

DO NOT CONNECT ANY SENSORS TO THESE DEVICES!!! The GPIOs on the Pow are connected to AC power! Only use them as designed.

The AC connection between Pow and Pow R2 is different, please check exactly which version you have.

  • Pow R2: Lo-E-E-Li-N-N = LineOut-EarthOut-EarthIn-LineIn-NeutralOut-NeutralIn
  • Pow: Lo-E-E-N-N-Li = LineOut-EarthOut-EarthIn-NeutralOut-NeutralIn-LineIn

Serial Flashing

Please see the Hardware Preparation page for general instructions.

3V3, RX, TX and GND pins are available at the rear/short end of the PCB.

To enter flash mode, press down on the button while powering the device.

Note - After the module type is changed to "Sonoff Pow R2", the serial port is no longer available for entering configuration commands because the serial port is used to communicate to the power measurement chip. Make sure you have set up your network connection before doing this.

Serial logging

Serial logging is disabled by the Tasmota code for this module. Serial communication is used by the device to transfer the data from the energy monitoring chip to the ESP chip. Do not enable serial logging (SerialLog 0) on this device. It can cause the device software to crash. Be sure to leave it disabled.

Video tutorial by alsolh

Power Monitoring Calibration

Sonoff Pow R2 might need calibration as correct measurements are influenced by hardware and timing differences. See Power Monitoring Calibration


The Sonoff Pow R2 can provide Energy, Power, Voltage and Current information in different ways.

The preffered way is using the periodic telemetry data. Default setting TelePeriod 300 will send telemetry data every 5 minutes.

If the setting PowerDelta (new since version 5.12.0e) is not 0 (default 80%), telemetry will be sent on power change too.

tele/pow1/SENSOR = {"Time":"2018-02-15T17:37:10","ENERGY":{"TotalStartTime":"2018-11-14T18:39:40","Total":6.294,"Yesterday":5.340,"Today":0.954,"Period":217,"Power":2635,"ApparentPower":2650,"ReactivePower":282,"Factor":0.99,"Voltage":227,"Current":11.661}}

To request information you can use command Status 8.

stat/pow1/STATUS8 = {"StatusSNS":{"Time":"2018-11-15T08:54:18","ENERGY":{"TotalStartTime":"2018-11-14T18:39:40","Total":6.404,"Yesterday":5.340,"Today":1.064,"Power":2629,"ApparentPower":2645,"ReactivePower":288,"Factor":0.99,"Voltage":226,"Current":11.677}}}

The presented information has the following meaning:

Message        | Unit | Description
TotalStartTime | Date | DateTime of calculation for Total
Total          | kWh  | Total Energy usage including Today
Yesterday      | kWh  | Total Energy usage between 00:00 and 24:00 yesterday
Today          | kWh  | Total Energy usage today from 00:00 until now
Period         | Wh   | Energy usage between previous message and now
Power          | W    | Current effective power load
ApparentPower  | W    | Power load on the cable = sqrt(Power^2 + 
               |      | ReactivePower^2)
ReactivePower  | W    | Reactive load
Factor         |      | The ratio of the real power flowing to the load to
               |      | the apparent power in the circuit 
Voltage        | V    | Current line voltage
Current        | A    | Current line current

Official Sources

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