Overview

ESP32 SmartMeter that reads data from Kaifa MA309 and converts it to Sunspec data model on Modbus server. Using Esphome framework providing web-ui and OTA-update.

Credits

This is an extension of this project. Thanks a lot for the good work.

Tested with

• Fronius Gen24 inverter: config => "Kommunikation/Modbus RTU" as "Master"; add "Komponente/Primärzähler"
• Kaifa MA309 on VKW ( Vorarlberg Netz ). Note: Needs security key from energy provider.
• Note: MQTT was not used and never tested

HW

• esp32 Lilygo RS485 / CAN. CAN-bus is not needed.
• M-Bus board
• wiring is similar to "credits" project, but see m-bus definitions in smart_meter.yaml for Lilygo board
• Fronius wiring: Modbus RTU shield, +, - to esp.RS485 A, B

Description

• Kaifa broadcasts data in ~5sec interval
• receive data via M-Bus and convert them to Sunspec data model
• provide data on Modbus RTU - server
• Fronius inverter reads data in ~1sec interval
• if everything works correct, esp.led blinks green

Build SW

• read the "SW installation" in the "credits" - project ( add your security key )
• for USB connection run (use your ttyUSB): "esphome run ./smart_meter.yaml --device /dev/ttyUSBx"
• for Wifi connection run (use your local address): "esphome run ./smart_meter.yaml --device 192.168.xxx.xxx"
• optional build / run the tests in "test" folder
  • smart_meter_client: used to test the Modbus - server communication with an other Lilygo board running a Modbus - client
  • GTest: for Sunspec model and Modbus - server

Known issues

• "cos-phi" is low on low energy flows