MQTT - Add Offset


(Alex) #1

Hi,

I’ve just received a Shelly H&T Sensor for Humidity & Temperature.
It works really fine but it seems to take it’s own heat into account.
That means that it reports a steady 20°C when it should in reality only have 18°C. This is expected because every electronic device causes heat.
Now I want to have an offset in there to properly subtract that value.
I created the items in PaperUI so I can understand how MQTT works :stuck_out_tongue:

I stumbled across the “Transform values” but I have no clue how they work or what I can do with them. It should basically just take the received string (in my case a number) and subtract a defined value and then communicate that to the item that is attached to that.
According to the API Sheet from Shelly, it just delivers a number.


(Rossko57) #2

(Nick Galfas) #3

I also have this “problem” with my temp sensors. I hacked the Sonoff Touch to have a BMP280 sensor on the bottom side of the glass. Half of the sensor is out on the air but still gets warmer readings than from the sensor itself being hanging out on the air from its cable…


(CM6.5 H102) #4

Use the rules within tasmota to offset the temp accordingly or flash Esp Easy firmware and use the built in offset feature.


(Nick Galfas) #5

Yeah, i did that. I was pointing out the hardware issues about the heat and the sensor.


(Alex) #6

Oh my god - That was it. Thank you so much.
I totally did not knew that I can change the Profile from “DEFAULT” in PaperUI to reflect any status I need. In my case “Offset”. I thought it’s only possible through the .item-file.

For everybody that runs in the same issue as I do with PaperUI:
When creating the new item by linking the channel to the new Item, under “Profile” the appropriate value should be selected.
After adding the Item, the Question for an Offset is coming up.

Thanks and have a great day!