Greetings, fellow Home Assistant enthusiasts! 
I’m Klaus, a newcomer making the switch from Homematic CCU3 to Home Assistant. While I’ve managed to tackle many aspects of this transition, there’s one challenge that has me stumped—creating internal binary and numerical variables within Home Assistant. 
Here’s my conundrum: I want to use a physical switch to toggle an internal binary variable (let’s say, to set my pool to ‘automatic mode’) and then link this state to another action, like adjusting my heat pump based on current energy feed-in values. Additionally, I need several internal numerical variables to track hourly and daily rainfall totals. While I can get the overall rainfall data from my CCU3, I need to calculate these internal values myself. 
My plan is to start fresh each hour by saving the current rainfall value into a variable. Then, every five minutes, I’d subtract this saved value from the current reading to determine the hourly rainfall. At the end of the hour, I’d move this value to the ‘last hour’ variable and reset the current hour counter to zero. I’d repeat a similar process for daily totals, triggering updates at midnight instead. 
I’m confident this approach could work, but I’m not entirely sure how to implement it within Home Assistant. Is there a built-in feature or a recommended method for creating and managing these variables? Any guidance would be greatly appreciated! 
I’m also curious if others have tackled similar projects and how they approached variable management. Sharing experiences could help us all refine our setups. Looking forward to your insights! 