Originally Posted by
Conseils
The Android and Apple Apps accept 0.5°C (probably API 2.X)
So my guess at the moment is that the Honeywell version 2 API does indeed take 0.5C, as does the Evohome controller.
Originally Posted by
Conseils
I look forward to Alexa supporting 0.5°C increments, especially now I have 0.1°C room temperature resolution courtesy of the API update earlier this year ;-).
Psst....
Don't tell anyone, but the Honeywell V2 Web API actually supports setting set points with at least 0.1 degree resolution, for example 21.3 degrees...
You can do this via Domoticz or other custom script that accesses the API. I have not tried the V1 API to see if it can also set sub 0.5 degree increments as Domoticz uses V2.
I have confirmed in the past that the Evohome will actually act on these in between set points in terms of regulating the temperature, although I don't recall whether it still rounds the set point to the nearest 0.5 for display on the screen. (I'm not home just now to check but will check tonight)
The iPhone app will not let you set a value in between 0.5 degree increments but it will display in between set points rounded to the nearest 0.1 degrees - for example if I set a zone to 5.79 in Domoticz the iPhone app reports 5.8 degrees not 6.0.
Returned results from the V1 and V2 API's is interesting - the V2 API will return the full two decimal place resolution for the set point:
Code:
{'temp': 16.5, 'setpoint': 5.79, 'thermostat': 'EMEA_ZONE', 'name': u'Main Bedroom', 'id': u'1438045'}
However the V1 API despite having greater resolution for measured temperatures seems to round set points to 0.5 degrees:
Code:
{'temp': 16.86, 'setpoint': 6.0, 'thermostat': u'EMEA_ZONE', 'name': u'Main Bedroom', 'id': 1438045}
So as far as retrieving temperatures and set points from the API's is concerned, for highest resolution it still seems to be best to retrieve the measured temperature from the V1 API and everything else including set point from the V2 API, which is what the Domoticz evo-update.sh script now does.
Interestingly when you make the initial override using Domoticz it displays the set point rounded to 0.1 degrees at first but after the next API check-in to retrieve the actual values from the server it updates to the two decimal place reading returned from the API. This seems to be a function of the Domoticz code rounding its "placeholder" value to the nearest 0.1 degrees. (Looks like some more rounding code in Domoticz that could be removed... )