value_template: >-
{% set t = states('sensor.synology_dsm_total_size_volume_1')|float %}
{% set u = states('sensor.synology_dsm_used_space_volume_1')|float %}
{{ t - u }}
Thanks. I use your template and get value 0.0. It’s supposed to be 0.2. What else I need to do?
The values of the source sensors are 2.7Tb and 2.5Tb. Are they string, and not value?
Thanks
The were strings until we cast them as floating point numbers.
Try this in the development tools template editor:
t = {{ states('sensor.synology_dsm_total_size_volume_1')|float }}
u = {{ states('sensor.synology_dsm_used_space_volume_1')|float }}
t - u = { states('sensor.synology_dsm_total_size_volume_1')|float - states('sensor.synology_dsm_used_space_volume_1')|float }}
t = {{ states('sensor.synology_dsm_total_size_volume_1')|replace('Tb','')|float }}
u = {{ states('sensor.synology_dsm_used_space_volume_1')|replace('Tb','')|float }}