ESPHome Modbus configuration for Schneider iEM3155 Energy Meter v1.2

Revision:

• v1.2 (2023-09-08)

  • Further code revisions to avoid wrong initial values on reboots (not power cycles)
  • Minor fixes
    • Substitutions, icons, diagnostic sensors etc.

• v1.1 (2023-07-17)

  • Improved documentation
  • Added two additional (calculated) sensors. The daily solar power self-consumption sensor rely on daily yield value from my solar inverter via a Home Assistant sensor
    • Daily solar power self-consumption sensor
    • Daily export power sensor
  • Code revised to be more resilient to reboots (not power cycles)
    • Daily export power base value is now retained in RTC memory

This repo contains my production configuration and serves as a complete ESPHome example for the iEM3155 Energy Meter.

Extremely easy, full Home Assistant integration using ESPHome as wireless Modbus node.

iEM3155 ESPHome sensors exposed to Home Assistant:

iEM3155 device configuration:

• Serial: 19200, EVEN, 1 (default)
• Slave address: 0x01

Note

Ensure that Com.Protection in the device is DISABLED - Com.Protection is ENABLED by default !!

Otherwise partial reset of daily energy import registers will be IGNORED by the device (id: daily_energy_import_total + 3 x daily_energy_import_lX)

ESP8266 module:

Wemos D1 Mini v3

RS485 modbus module

• XY-017 'Noname' AliExpress TTL <--> RS485 module
• Simple, cheap module
• Supports both 3.3 and 5v
• 'No hazzle' module with hardware automatic flow control

The iEM3155 device also offers some additional interesting features that might be useful for others. Tariff/tariff rates and overload alarm. There's also both a digital input and output port that can be utilized as well.

Check the iEM3155 user manual/technical datasheet for further info