Tasmota: How to extract the AnalogA0 input value from Wemos D1 mini MQTT topic and change value in Home Assistant

Created on 17 Mar 2019 · 3Comments · Source: arendst/Tasmota

I installed latest version of Tasmota on a Wemos D1 mini and also commented the ADC voice to read the AnalogA0 input value. This value is given correctly in the main page ranging from 0 to 1024.

09:14:01 MQT: tele/wemos_3/STATE = {"Time":"2019-03-17T09:14:01","Uptime":"0T00:40:20","SleepMode":"Dynamic","Sleep":50,"LoadAvg":38,"POWER":"OFF","Wifi":{"AP":1,"SSId":"In_medio_stat_virtus-2GHz","BSSId":"A0:63:91:E0:A4:87","Channel":1,"RSSI":98}}
09:14:01 MQT: tele/wemos_3/SENSOR = {"Time":"2019-03-17T09:14:01","ANALOG":{"A0":1024}}

When I go in the console I can see that every 5 minutes a new MQTT topic is fired with the Analog value. I would like to take this value, report it in Home Assistant and also convert it.

However, first I did not understand how to extract this value to be reported in Home Assistant. This is the code I am using which is for sure not correct.

sensor:
  - platform: mqtt
    name: "Plant Humidity"
    state_topic: "tele/wemos_3/SENSOR"
    unit_of_measurement: '%'
    value_template: "{{ value_json.A0 }}"

Another question would be if you know how to convert directly in home assistant this value ranging from 0 to 100% knowing that 1024 would be 100%. I know it can be done but I am very newbie to this.

Finally, the analog input is attached to a soil moistuire sensor. Attached to the same Wemos there is a relay shield. I noticed that when I switch on/off the relay, also the analog value is a little bit influenced (like it changes to 1018 from 1024 for instance). Is that normal?

invalid

Source

garret

Most helpful comment

A thousand apologies for my English. I had the same concern and resolved it as follows:

value_template: "{{(value_json ['ANALOG']. A0 | float * 100/1024) | round (1)}}"

So I can convert an analogous reading into a value for example percentage in a simple way without having to use jinja templating.

orlandperz on 25 Apr 2019

🎉2

All 3 comments

Should be value_json.ANALOG.A0 since A0 is nested under analog
the other question is for the home assistant support, it involves jinja templating and is out of the tasmota realm