Expandable 6 Channel ESP32 Energy Meter Main Board

Description

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.

With ESPHome loaded on the ESP32, the 6 Channel Energy Meter can easily output energy data to the new Home Assistant Energy Dashboard. Individual circuits, solar, as well as whole house energy can be imported into Home Assistant.

See this order page to save 5% on bundled items.

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

Features:

• 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-CT6) & 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-CT6
• SPI Interface

What you’ll need:

• Current Transformers (depending on your application)
  • • SCT-006 20A/25mA micro CT (6mm opening – 3.5mm connectors)  – these are great if you have a lot of 15A circuits that you want to monitor
    • SCT-010 80A/26.6mA mini CT (10mm opening – 3.5mm connectors)
    • SCT-013-000 100A/50mA (13mm opening – 3.5mm connectors)
    • SCT-016 120A/40mA (16mm opening – 3.5mm connectors) – for monitoring mains
    • Others can also be used as long as they’re rated for the amount of power that you are wanting to measure, and have a current output no more than 720mV.
• AC Transformer: Jameco Reliapro 9v or 12v. The positive pin must be 2.5mm (some are 2.1)
• ESP32 (choose one):
  • NodeMCU
  • Espressif ESP32-DevKitC
  • Espressif ESP32-DevKitC-32U or ESP32-DevKitC-VB (WROVER) if you need better wifi reception (don’t forget the antenna)
  • Anything else with the same pinouts as the above, which are usually 19 pins per side with 3v3 in the upper left & CLK in the lower right
• A 3d printed case (optional)
• Software (choose one):
  • Our custom version of EmonESP and the ATM90E32 Arduino library
  • ESPHome. Details on integration with Home Assistant are located here, and here.
  • Libraries for CircuitPython & MicroPython