Read and write modbus register directly from slider entity

Configuration
1

I would like to have a slider entity representing the temperature in a particular room (Celcius) that is synced with the HVACs modbus register (deci Kelvin). Note the transformation between Celcius and deci Kelvin.

Currently I have the following modbus configuration together with one input_number entity and sensor that are being synced with two automations. The current setup does the job, but I am hoping to find a more clever way without having to use automations.

Configuration:

modbus:
 - name: hvac_modbus
   type: tcp
   host: 1.2.3.4
   port: 502

input_number:
  setpoint_room:
    name: Setpoint Room
    min: 18
    max: 26
    step: 1
    unit_of_measurement: °C
    icon: 'mdi:thermostat'

sensor:
 - platform: modbus
   scan_interval: 10
   registers:
     - name: setpoint_room
       hub: hvac_modbus
       unit_of_measurement: °C
       slave: 1
       register: 4014
       scale: 0.1
       offset: -273

To keep the slider entity and the modbus register in sync I have the following two automations (getter and setter):

- id: sliderSetSetpointTemperature
  alias: Slider Set Setpoint Temperature
  trigger:
    platform: state
    entity_id: input_number.setpoint_room
  action:
  - service: modbus.write_register
    data_template:
      hub: hvac_modbus
      unit: 1
      address: 4014
      value: '{{ states.input_number.setpoint_room.state | int * 10 + 2730 }}'
- id: sliderGetSetpointTemperature
  alias: Slider Get Setpoint Temperature
  trigger:
    platform: time_pattern
    seconds: 10
  action:
  - service: input_number.set_value
    data_template:
      entity_id: input_number.setpoint_room
      value: '{{ states.sensor.setpoint_room.state | int }}'
1 Like
2

Just used your idea and it does work. Have a similar case and try to find a solution.

Not sure if this helps bu t found this:

He is using a script.
cheers A

1 Like