How to change sensor value

Configuration
1

Hi everyone, I need to get sensor value from modbus, and then perform some math actions with it. For example, here my configuration.yaml

modbus:
  - name: modbus_hub
    type: serial
    port: /dev/ttyUSB0
    baudrate: 38400
    bytesize: 8
    method: rtu
    parity: N
    stopbits: 1
    sensors:
      - name: Sensor1
        unit_of_measurement: °C
        address: 40001
        slave: 1
        input_type: holding
        data_type: int16
        scan_interval: 1

How can I substract from it value, or use it in another scripts?

Thanks!

2

To subtract a number from your sensor value use the scale option. e.g. to subtract 42:

modbus:
  - name: modbus_hub
    type: serial
    port: /dev/ttyUSB0
    baudrate: 38400
    bytesize: 8
    method: rtu
    parity: N
    stopbits: 1
    sensors:
      - name: Sensor1
        unit_of_measurement: °C
        address: 40001
        slave: 1
        input_type: holding
        data_type: int16
        scan_interval: 1
        offset: -42

There is also a scale option.

output = scale * value + offset

3

Ok, thanks. But how I can perform div/mod operation?

Also, important question is how I can get value of this sensor to use in other scripts?

4

Divide by 2 would be:

scale : 0.5

Modular arithmetic function is not available you would have to feed your modbus sensor to a template sensor. E.g. mod 42:

template:
  - sensor:
      - name: My modified sensor value
        state: "{{ states('sensor.sensor1')|float(0) % 42 }}"
        unit_of_measurement: "°C"
        device_class: temperature 
        state_class: measurement

You use templates in services in scripts to get the value of your sensor. e.g.

sequence:
  - service: input_number.set_value
    target:
      - entity_id: input_number.answer
    data:
      value: "{{ states('sensor.sensor1') }}"
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