Expandable 6 Channel ESP32 Energy Meter Main Board

(2 customer reviews)



Frequently Bought Together

NodeMCU-32s - ESP32 ESP-WROOM-32 Development Board


Jameco AC 120V 60Hz to AC 9 Volt Wall Adapter Transformer @ 1000mA Black Straight 2.5mm Female Plug

SKU: EM-6chan Category: Tag:


The Expandable 6 Channel ESP32 Energy Meter can measure the amount of current being used by 6 circuits at a time! Much like our Split Single Phase Energy Meter, the 6 channel energy meter uses current transformers to measure current being used by any circuit, and an AC transformer to measure voltage. An ESP32 dev board plugs directly into the energy meter to process the meter data and send it over WiFi.

Up to 6, 6 channel add-on boards can stack on top of the main board to allow you to monitor up to 42 current channels in 16-bit resolution, in real time, all at once! Each add-on board can measure an additional voltage channel.

This product is currently in the prototype stage, so components may change.

See the latest hardware and software documentation in the Github repository.

Backorders will be shipped within 5 business days.


  • Samples 6 current channels & 1 voltage channel (expandable to 2 voltage – requires an additional AC transformer)
  • Add-on boards (up to 6) can expand the meter up to 42 current channels & 8 voltage channels
  • AC power from the transformer is converted into DC, which goes into a buck converter to power electronics
  • Uses 2 Microchip ATM90E32AS:
    • 3 current channels (CT1-CT3 & CT4-CT5) & 1 voltage per IC
    • Measurement Error: 0.1%
    • Dynamic Range: 6000:1
    • Current Gain Selection: Up to 4x
    • Voltage Reference Drift Typical (ppm/°C): 6
    • ADC Resolution (bits): 16
  • For each current channel the following can also be calculated by the meter:
    • Active Power
    • Reactive Power
    • Apparent Power
    • Power Factor
    • Frequency
    • Temperature
  • Uses standard current transformer clamps to sample current
  • 22ohm burden resistors per current channel
  • 2 IRQ interrupts, and 1 Warning outputs
  • Zero crossing outputs for each current channel
  • Energy Pulse outputs per IC (4 per IC x2)
  • Active Power LED pulse for CT1-CT3 & CT4-CT5
  • SPI Interface

What you’ll need:

Additional information

Weight 2 oz
Dimensions 4 × 4 × 1 in
CT Connectors

3.5mm, Quick Connect Screw

Change Log

12/16/2019 – v1.4
– Added optional micro-hdmi connection to connect the current transformer remote board. This allows for all 6 current transformer connections to connect to a remote pcb, which then connects to the main board via 1 micro-hdmi cable. Instead of 6 wires coming out of the meter, there can now be 1.
– Removed JP9-JP11 and connected all voltage channels together for each ATM90E32

10/15/2019 – v1.3 rev1
– Added voltage divider on ground for voltage channel 2

10/1/2019 – v1.3
– Added voltage divider on ground for voltage channel 1
– Added 20k pullup for voltage channel 1
– Changed all voltage dividers to 20k and 1k so voltage input from a 12v AC transformer is around 650mV
– Removed C37

8/1/2019 – v1.2
– Added C37 to connect neutral and DC ground
– Added solder jumpers JP9-JP12 to connect all voltage channel inputs together

6/1/2019 – v1.1 – Initial public release

2 reviews for Expandable 6 Channel ESP32 Energy Meter Main Board

  1. Samuel Reyna (verified owner)

    I purchased one of these to test out and see if I could get it working. It didn’t take me long to get it all figured out. This board is amazing and does exactly what is says that it will do. Amazing. I will be purchasing 6 more boards. It is not cheap, but it is the best solution if you want to monitor all your circuits. I’m getting continuous data readings sent to my PC, all the time. I can select any day that I want and look at the data for that day. I have found several devices in my house that are “off”, but consuming .5 amps of power at all times. Completely amazing board!

  2. Paul (verified owner)

    Great product and even better service.
    Couldn’t be happier with it.

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