Looking for guidance - single read multiple register MODBUS to multiple sensors - struggling with template

Configuration
1

I have a heatpump and with

  sensors:
    - name: HP
      unique_id: HPA
      slave: 1
      address: 2035
      input_type: holding
      data_type: custom
      scan_interval: 2
      count: 45
      structure: ">HHHHH10xHHHHxxxxxxHHxxH32xHHHHHHL"

in an imported modbus.yaml, I get a sensor which reads 90 bytes every few seconds and gives a string like

0.00,0.00,0.00,0.00,0.00,415.00,402.00,467.00,183.00,414.00,240.00,311.00,0.00,119.00,0.00,0.00,0.00,0.00,8449.00

all very straightforward as sensor.hp_2

In Developer | Template I’ve got:

template:
{% set HP=states('sensor.hp_2').split(',') %}
  - sensor
    - name: "Heating Return Temp"  
      - state: "{{ HP[0]  | float / 10 }}"

    - name: "Heating Leaving Temp"
      - state: "{{ HP[1] | float / 10 }}"  

    - name: "DHW Tank Temp"
      - state: "{{ HP[6] | float / 10 }}"

and that works as expected splitting the string into an array once then using the array to populate 3 sensors (in reality there will be lots more).

I cannot for the life of me figure out how to make them work as sensors in config.yaml and have scoured the net for examples but it looks like the templating system has changed?

I could do 3 separate splits in 3 separate sensors (done, works) but that’s ugly. It should be 1 split and 1 intermediate array.

Basically, what’s the recommended way to take data from 1 sensor (in this case a comma separated string) and create/update a large number of sensors from that data.

Before I tear even more hair out… can some kind soul point me in the right direction?

2

I believe that is the only way in HA.
Three splits.
You could create a macro template, but in the background it’s till going to be three splits.

EDIT:
You might be able to be creative and use the rest API of HA to get the values and then use this:
RESTful Sensor - Home Assistant
But… it seems you just keep following the rabbit hole if you do.

3

Thanks @Hellis81 - I’d feared that might be the case but it just seemed such an obvious optimisation that I thought "surely… this is do’able’.

4

Ok… got a plan B to try.

My basic aim is read multiple registers using modbus as a bulk read, slice and dice that data and make it available within HA in an efficient way. Much reading around HA later that seems suboptimal so plan B!

hacs-pyscript looks like it will run periodic (it’s a heatpump so doesn’t need ms resolution) python with something like https://community.home-assistant.io/t/modbus-sensor/6751/9 getting the values up to HA without too much hassle.