MDT Smart Glass II and smart thermostat setpoint problem

Configuration
1

Hello,

I’m new to Home Assistant and KNX, I’m having difficulties with the MDT Smart Glass II (rev 1.7) and home assistant for the thermostat features.

I’d like to use the MDT buttons to change the temperature setpoint but it doesn’t work.
I configured a KNX climate device, I can change the setpoint from home assistant and the change appears immediately on the MDT device but the other way it doesn’t work.
The MDT button is configured to use 2bytes. (setpoint shift and setpoint shift state both on 4/3/3 with all flags)
I guess I’m missing something with the setpoint shift feature. I don’t know if it’s from the ETS configuration or from the home assistant side.
I tried different solutions I read here and there on the forum but without success as they include a KNX heating actuator and I guess it’s a part of my problem.

For the heat regulation I was planning to use the smart thermostat integration to trigger an on/off 230v actuator (heaters will have electric valves) instead of a KNX heating actuator.
I may be wrong but it seems to me to be a more flexible solution than a KNX heating actuator, knowing that I may be installing air conditioning in the future, I could more easily switch between both.

In my current apartment I have a cheap Jeedom setup with Sonoff relays and it’s smart thermostat plugin which gives me a lot of flexibilty in it’s configuration and I had in mind to do the same thing.

Is it a good idea or should I install a KNX heating actuator?

At this time my setup looks as below:

KNX climate device:

    - name: "Grande Chambre"
       temperature_address: "8/1/3"
       temperature_step: 0.5
       setpoint_shift_address: "4/3/3"
       setpoint_shift_state_address: "4/3/3"
       setpoint_shift_mode: 'DPT9002'  
       target_temperature_address: "4/4/3"
       target_temperature_state_address: "4/4/3"
       operation_mode_state_address: "4/6/3"
       min_temp: 7.0
       max_temp: 32.0

This is the part where it already doesn’t work to change values from the MDT switch even if I see messages of +1 +2 … going to the 4/3/3 group when I press on the buttons of the switch.
I guess the value not changing has to do with a +1 +2 added to nothing?

The second part of my question
To send the value of the KNX climate temperature device sensor to the Smart Thermostat I use a template, but how should I do if I change the temperature setpoint in the smart thermostat integration to have the value sent back to the KNX climate.
I searched on the forum and the documentation but I’m not sure if I’m not searching a complicated solution to a simple problem.

Thanks

Configuration to send the temperature from the KNX climate device to the Smart Thermostat.

- platform: template
    sensors:
     grande_chambre_temperature_attribute:
        friendly_name: "Temperature Grande Chambre"
         unit_of_measurement: 'degrees'
         value_template: "{{ state_attr('climate.grande_chambre', 'current_temperature') }}"

Smart Thermostat configuration

 #Grande Chambre
   - platform: smart_thermostat
     name: Thermostat Grande Chambre
     unique_id: smart_thermostat_grande_chambre
     heater: switch.on_off_heater
     target_sensor: sensor.grande_chambre_temperature_attribute
     outdoor_sensor: sensor.exterieur_temperature_attribute
     min_temp: 7
     max_temp: 28
     ac_mode: False
     target_temp: 19
     keep_alive:
       seconds: 60
     away_temp: 14
     eco_temp: 17
     comfort_temp: 21
     sleep_temp: 19
    # autotune: "ziegler-nichols"
     kp : 5
     ki : 0.01
     kd : 500
     pwm : 00:15:00
2

A KNX climate entity is an interface to control and get data form a KNX heating actuator. It has no regulator functions or setpoint logic whatsoever - this is expected to be provided by the actuator.

A KNX heating actuator is probably a more resilient solution. It works independent of HA, networking, etc., and don’t use magnetic relays wich wouldn’t last very long due to the many switch cycles a PWM signal implies.
Adding air conditioning doesn’t really have to do anything with that - just turn off the internal regulator when not heating (with a heat/cool GA for example)