Bathroom towel rack¶
This recipe is about how to use the towel rack in the bathroom to dry the towels after somebody has showered, so that the towels are ready for use for the next time that somebody showers, whatever time that may be.
In this example we aren't trying to heat up the towels before use, as that would require us to know at what times people shower.
Requirements¶
- Zone Shower - an occupancy sensor which tells us when somebody is in the shower
- Radiator - the towel rack
Scene: Person in shower¶
The first scene is intended to turn on the towel-rack (or radiator) once somebody has been detected in the shower for at least 10 seconds. The 10-second delay is to account for jitter that is often seen with presence sensors.
Scene: Radiator off after 2 hours¶
The second scene is intended to turn the radiator off after it has been on for two hours, which should be enough time to ensure the towels are dry.
An entity state condition has a higher priority than an occupancy condition which means that turning the radiator off after 2 hours takes priority over detecting a person in the shower.
Problem: Multiple showers¶
What if somebody has a shower 1h55 minutes after the first person? The radiator would turn off 5 minutes later and the newly wet towels wouldn't have time to dry.
We could switch the order of the conditions:
This wouldn't solve the problem because, when the second person enters the shower, the radiator is already on and so the last-updated time wouldn't be updated.
Scene: Block until shower clear for 2 hours¶
Instead, we can add a third scene which will block until the shower has been clear for at least two hours, and move the radiator-off scene below that:
Lifecycle¶
| Trigger | Matched Scene | Action |
|---|---|---|
| Person enters the shower for 5 seconds | No match | None |
| Person enters the shower for 10 seconds | Person in shower | Radiator turns on |
| Person leaves the shower after 10 minutes | No match | None |
| Person enters the shower 1 hour later | Person in shower | None — already applied |
| Person leaves shower | Block until shower clear | None |
| Shower clear for 2 hours | Radiator off after 2 hours | Radiator turns off |