Added:

• Energy HiRes sensor for Multical 403 meters
• Multical meter type defined in substitutions. Remember to alter to YOUR meter type!
• Expose to- or hide sensor from HA depending on defined Multical meter type
• energy_uom added in substitutions. Change default 860 to 0.86, if you use a meter with kWh as UOM for Energy registers

Revised:

• Separate calculation of cooling average sensors base values

Added:

• Yearly Cooling average sensor + timestamp. Autoresets at January 1st, 00.00 hours

Revised:

• Various logging messages

Revised:

• Registers returning zero values was previously ignored and not sensor updated (was treated as an error read). Now sensors will be updated with zero values
• Register reads throttle is revised from 1- to 5 minutes = 30.000 millis
• timeout value in kmp.h revised from 200 to 250 ms.

Added:

• HiRes energy register handling added to kmp.h and multical402.h
• multical402.yaml renamed to multical602.yaml
• Revised multical602.yaml to calculate and publish a new high resolution energy sensor
• Tested and working on a Multical 602 device

This is a custom component for esphome that can read values from a Kamstrup Multical 402 meter. This meter type is used for district heating for the most.

The code is combined and adapted from other sources, see Sources & Inspiration below.

The meter is using KMP (Kamstrup Meter Protocol) for communication which is also used in power meters, but the code in this repository is written to read specific register values.

The Multical 402 meter is equipped with an optical communication port. In order to communicate with the meter an Optical Reader is needed.

These are typically equipped with an USB port and are rather expensive, but for this project we only need a simple circuit that can be controlled by the ESP chip.

Options:

• Prebuilt: https://www.ebay.com/usr/arelektronik – this is what I got
• DIY: https://wiki.hal9k.dk/projects/kamstrup - in Danish

However, I don't think it's feasible making your own. The one from ebay is really cheap (18 EUR), but if you have a 3D printer already you can get the pcb and magnet for only 11 EUR.

Update the multical402.yaml file as follows.

In my case I'm using a Weemos D1 mini clone, but make sure to specify the right board here. Get more info here.

esphome:
  board: d1_mini    <-- Set the right board here
  ...

Specify wifi credentials.

wifi:
  ssid: INSERT_WIFI_SSID
  password: INSERT_WIFI_PASSWORD

The optical reader has 2 connections (besides VCC and GND). Specify them here:

uart:
  - id: uart_bus
    rx_pin: D1      <-- Set RX pin
    tx_pin: D2      <-- Set TX pin
    ...

The code will run every 10 seconds. This can be changed here:

custom_component:
  - lambda: |-
      auto multical402 = new Multical402(
        10000,      <-- Specify update interval in milliseconds
        ...

Currently the code is hardcoded to read the following register values:

• Energy (Wh)
• Power (W)
• Temperature In (°C)
• Temperature Out (°C)
• Temperature Diff (°C)
• Flow (l/h)
• Volume (m3)

The code (kmp.h) can be changed to read other registers, but that is outside the scope of this readme.

Make sure to specify the unit of measurement on the sensors to match the value from the meter (eg. Wh vs kWh vs MWh).

sensors:
- name: 'Energy'
    ...
    unit_of_measurement: MWh  <-- specify unit of measurement here
    ...

In case no values are being read and the log shows something like this:

[21:04:37][D][Multical402:048]: Start update
[21:04:37][W][Multical402:163]: Timed out listening for data
[21:04:37][W][Multical402:163]: Timed out listening for data
[21:04:38][W][Multical402:163]: Timed out listening for data
[21:04:38][W][Multical402:163]: Timed out listening for data
[21:04:38][W][Multical402:163]: Timed out listening for data
[21:04:39][W][Multical402:163]: Timed out listening for data
[21:04:39][W][Multical402:163]: Timed out listening for data
[21:04:39][D][Multical402:078]: End update

Check the following:

• Check the IR LED on the optical reader; use a mobile phone and use the camera, the IR LED should blink every 10 seconds (or other if the update interval has been changed). If this isn't the case, check the UART pins and the wiring.
• Press the "play" button on the meter to enable the IR Port. The meter will turn off the optical port after 30min of inactivity on either buttons and optical port.
• Make sure the optical reader is positioned the right way; turn it 180° to flip the position of the IR sensor.

• https://github.com/Hal9k-dk/kamstrup/tree/master/Software%20eksempler
• https://github.com/ProudElm/ESPHome_multical_sensor
• https://github.com/jjansen85/esphome_multical401
• https://github.com/sebbebebbe/Multical402MQTT
• https://github.com/nabovarme/MeterLogger/wiki/Kamstrup-Protocol

• https://github.com/nabovarme/MeterLoggerTesto/blob/master/5512447_M1_GB.pdf