Keep old value in sensor until a condition is true

Configuration
1

Hi,

i have some sensors that uses the same model-name and the same channel the only difference is the subtype provided in my JSON data.

some data:

home/rtl_433/JSON {"time" : "2020-11-01 10:38:19", "model" : "Prologue-TH", "subtype" : 5, "id" : 4, "channel" : 2, "battery_ok" : 1, "temperature_C" : 26.000, "humidity" : 24, "button" : 0}
home/rtl_433/JSON {"time" : "2020-11-01 10:37:33", "model" : "Prologue-TH", "subtype" : 9, "id" : 145, "channel" : 2, "battery_ok" : 0, "temperature_C" : 20.100, "humidity" : 71, "button" : 0}

I tried to configure it as a condition in value_template, but {{paul_temp}} is set to “nothing” if an other sensor publishes its value.

How can i keep the last “correct” value of my sensor?
(the condition itself works)

I tried this in sensors.yaml:

- platform: mqtt
  name: "Paul Temp."
  icon: "mdi:thermometer"
  state_topic: "home/rtl_433/JSON"
  unit_of_measurement: "°C"
  value_template: >
    {% if value_json.model == 'Prologue-TH' and value_json.channel == 2 and value_json.subtype == 5  %} 
        {% set paul_temp = value_json.temperature_C %}
        {{ paul_temp }}
    {% else %}
        {{ paul_temp }}
    {% endif %}

Thank you in advance!

2 
- platform: mqtt
  name: "Paul Temp."
  icon: "mdi:thermometer"
  state_topic: "home/rtl_433/JSON"
  unit_of_measurement: "°C"
  value_template: >
    {% if value_json.model == 'Prologue-TH' and value_json.channel == 2 and value_json.subtype == 5  %} 
        {{ value_json.temperature_C }}
    {% else %}
        {{ states('sensor.paul_temp') }}
    {% endif %}
3

Thank you very much!

1 Like
4

You’re welcome!

Please consider marking my previous post with the Solution tag. It will automatically place a check-mark next to the topic’s title which signals to other users that this topic has an accepted solution. This helps other users who may have a similar question and are searching for answers.