Anyway to get this to work with an ESP32?

[timothylui]

I bought this esp32 based opentherm gateway, can I get it to work with this, or do I need to get an ESP8266?

https://diyless.com/product/opentherm-thermostat

[sergeantd83]

We added some initial support for the OpenTherm adapter. @cnrd has a working SAT installation based on this board. If he has some spare time, he can provide some help to get it work. Meanwhile we are waiting for the official OpenTherm ESPHome component to fully support it.

[cnrd]

I am unsure of how familiar you are with esphome?

This is the configuration needed to setup opentherm on esphome, you will need to add the usual configuration on top of this, this is just the opentherm parts.

You may also need to update the pins used for communication, I am using an ESP32 S2 mini, but I think the pinout may be different on the ESP32 mini (not sure if you are reflashing the diyless one?)

You should not change the naming of any of the configured entities, they are named as SAT is expecting them.

Be aware that this is not a minimal example, I have added some extra fields that I use.

Let me know if you need more help 😄

external_components:
  source: github://olegtarasov/esphome-opentherm@main
  refresh: 0s

opentherm:
  in_pin: 33
  out_pin: 35
  ch_enable: true
  dhw_enable: true

number:
  - platform: opentherm
    t_dhw_set:
      name: "dhw_setpoint_temperature"
      min_value: 30.0
      max_value: 70.0
      step: 1
      initial_value: 55.0
      restore_value: true
    t_set:
      name: "ch_setpoint_temperature"
      min_value: 0.0
      max_value: 80.0
      step: 0.1
      initial_value: 0.0
      restore_value: true
    max_t_set:
      name: "max_ch_setpoint_temperature"
      min_value: 20.0
      max_value: 80.0
      initial_value: 80.0
      step: 1
      restore_value: true
    max_rel_mod_level:
      name: "max_modulation_level"
      entity_category: config
      min_value: 0
      max_value: 100
      step: 1
      initial_value: 100
      restore_value: true

sensor:
  - platform: opentherm
    rel_mod_level:
      name: "modulation"
    device_id:
      name: "boiler_member_id"
    t_boiler:
      name: "boiler_temperature"
    t_ret:
      name: "return_temperature"
    t_dhw_set_lb:
      name: "dhw_min_temperature"
    t_dhw_set_ub:
      name: "dhw_max_temperature"
    t_dhw:
      name: "Hot Water Temperature"
    ch_pressure:
      name: "Heating Water Pressure"
      unit_of_measurement: hPa
    t_exhaust:
      name: "Exhaust temperature"
    max_capacity:
      name: "max_capacity"
    min_mod_level:
      name: "min_mod_level"


binary_sensor:
  - platform: opentherm
    flame_on:
      name: "flame_active"
    ch_active:
      name: "Central Heating active"
    dhw_active:
      name: "Hot Water active"
    fault_indication:
      name: "Boiler Fault indication"
      entity_category: diagnostic
    diagnostic_indication:
      name: "Boiler Diagnostic event"
      entity_category: diagnostic

switch:
  - platform: opentherm
    dhw_enable:
      name: "dhw_enabled"
      restore_mode: RESTORE_DEFAULT_ON
      entity_category: config
    ch_enable:
      name: "ch_enabled"
      restore_mode: RESTORE_DEFAULT_ON
      entity_category: config

[sergeantd83]

Also you need to run the latest develop version in order to achieve connection.

[Thijssvd]

Hi, I have the diyless thermostat 2. Can you help with getting SAT on there? Does anyone know which the OT pins are?

[cnrd]

Actually ESPHome 2024.11 was just released two hours ago, so when I have time I will probably do a PR that updates everything to follow the official naming and include an example config.

I think it may be in_pin: 16 out_pin: 17 on the ESP32 mini

[timothylui]

Hi thanks for the help, I've got ESPHome up and running with opentherm, how do I install the develop version? It only gives me the following options

[timothylui]

If i try to add manually, i get this error.

[timothylui]

ignore me, I installed it manually

[sergeantd83]

Or download the latest version and then
go to developer tools -> services -> service -> update.install -> choose entity -> update.smart_autotune_thermostat_update -> check version -> fill develop -> call service

[timothylui]

ok thanks, that is a better way. I got it all set up, I'll find out tomorrow morning if it's working correctly whether my other half shouts at me that the kitchen is freezing cold...

[sergeantd83]

Some initial settings:
If you had an error during the overshoot protection value calculation then reconfigure SAT and manually add the value 50.
In settings -> General
Choose the Precision Curve
Improved controller
Heating Curve: 2
Automatic gains: 2
Derivative time weight: 2.5

[GravitySandwichh]

i tried above config but SAT seems to not do anything to the CV. During calibration nothing happens. After the integration is added, the boiler never turns on to heat.

[GravitySandwichh]

Got it working with the readme here:
https://github.com/sergeantd83/SAT?tab=readme-ov-file#opentherm