** This is work in progress **

esphome-modbus-client-xemex-csmb

ESPHome Modbus Client/Master component to pull info from the Xemex CSMB

Goal

This project pulls data from an Xemex CSMB and feeds it into HomeAssistant.

ESPhome YAML config

YAML Config
Of course, this should be adapted to your board etc, but the modbus config can be re-used as is.

Used hardware

The Xemex CMDB

https://xemex.eu/products/meters-sensors/csmb/
https://xemex.eu/wp-content/uploads/2021/07/User-manual-CSMB-1.0.pdf
Page 9 of the user manual contains info on the supported modbus functions.

Note that this module is also used by the Shell Recharge Advanced 3.0 Wallbox for its Dynamic Power Management.

The ESP32 Board I used

Link to product page on Azdelivery.de

The RS485 module I used

Link to product page on amazon.com.be

Sample output

Note that CT2 and CT3 are not connected to my Xemex CMDB

Raw Serial logs

Caveats

It looks like the reported current on the 3 "RMS Current CTx" is always positive. Even if electricity is being delivered to the grid the device reports a positive current. I don't there is a way to know if the CT is measuring electricity consumption or production.

Sister projects

Emulate a Xemex CSMB