homeassistant

Couple ideas, depending on what you have:

• When the warm water pipe heats up
• when the water heater starts drawing more power
• when the water meter detects warm water usage in the evening
• when the sound volume goes up in the bathroom
• when the weight sensors go off under the shower (or around it as you get in)
• when a movement sensor detects movement in the shower
• when a magnetic door sensor sees the shower curtains open
• when you press a (waterproof) button in the shower
• when a weight sensor under the shampoo holder detects less weight

Are u nekkid, but warm, and wet? You're in the shower.

mmwave sensor, humidity sensor, and/or monitoring your water heater power usage. any of those 2 should work.

I am actively working on a bunch of ML algorithms for home assistant for exactly this type of thing, detecting 'activity' per room.

You could use a classic dead man switch: Place several buttons around the whole place - basically everywhere except in the shower. Once you stop pressing any of these buttons for - let's say - 30 seconds you can assume you're taking a shower.

Multiple waterproof 4k cameras pointed at the inside of your shower from every angle and image recognition by some AI that detects when a naked person enters.

Don't forget to use Wifi and no firewall

Made a flowchart for you:

< Do you feel wet? >  
     |  
     +-- yes --> < are you indoors? >  
     |                |  
     |                +-- yes --> < are you wearing pants? >  
     |                |                      |  
     |                |                      +-- yes --> [ you peed yourself ]  
     |                |                      |  
     |                |                      +-- no --> [ you're taking a shower ]  
     |                |  
     |                +-- no --> [ it's raining ]  
     |  
     +-- no --> [ you are not taking a shower ]  

Without trying something similar yet, here are some ideas:

• motion sensor on top of your shower
• trying to detect the vibration of the water flow
• a simple switch that you hit before you get into the shower

Also think of other times you "use" the shower, like cleaning it. Some methods will also be triggered then.

If you have a shower cubicle, could you put a door open sensor on it, and assume you're showering if the door is closed? I think it's normal to leave the doir open when not in use. It would probably also work if you had a shower curtain, so long as you always pulled it all the way closed in use.

I would just go with special button, the most straightforward simple solution you have direct control over. Also sometimes you might need to use the shower without mood lights and then system based on humidity or water flow will just be annoyance.

If you use some tools when showering, like brush or spung, you can make a contact sensor into the hook/holder (more work, probably need a custom 3D print), but should also work and you don't need to press anything

Flowmeter on the shower head or down in the supply lines to the tub/shower?

I experimented with a humidity sensor in the shower and was surprised how quickly it spiked. It's how I woud do it. Other option would be a leak sensor in the basin but getting it to turn off at the right time would be very hard. You have a lot more control over this with a humidity sensor.

I'm using zwave for everything like this and wouldn't be at all concerned about battery for either scenario. Both would last years, much like my door and window sensors do.

I bet you can rig up something microphone-based, there's tons of software nowadays for analyzing audio, and you don't need to run the analyzing software on the device with the microphone anyway. Though the analyzing would likely take a little bit longer that you'd want it to.

I use a humidity sensor, motion sensor and a helper that shows the change over a period of time. If the humidity raises fast (+2%/5m) and goes over a certain amount (unique, depending on your room's climate) the bathroom automation changes tracks to hold the light at 100%, turn the extractor fan on, and well, how you stop the automation depends on you. I let it stay on for 15 minutes before waiting for motion. Small tips: For me the humidity triggers the automation within 15s-1m of showering, which is okay for me. Motion sensors typically use IR to see movement. If the room is too steamy it might struggle to see you. Also, it cannot penetrate glass. It must have a line of sight to you.

The best alt I think would be mmwave presence sensors, but they're pricy and require a wired connection.

@batshit I tend to use the fact that I'm naked and wet as my cues.

I'd settle for the small lag with a humidity sensor. If you're the type to run the shower for a minute before getting in, it should kick in in that time.

Could do a presence sensor or motion sensor pointed at the shower. Haven't played with either, and you'd have to figure out water resistance.

Not sure if you have access to the pipes leading to the shower, but the droplet does what you're looking to do.

https://hydrificwater.com/

Crossposted from showerthoughts

I would use something like this to measure water usage in combination with an presence sensor in the shower stall. Water flowing + someone present in shower stall = someone taking a shower.

This is a fun question.

I have to assume the absolute ideal would be some sort of water flow detection right in line with the shower head. Likely hard wired. But like I said, that’s an ideal.

I think the other suggestions in the thread are reasonable. The microphone one seems most appealing to me since that could theoretically just occupy an outlet anywhere in the room.

Motion sensor positioned really close to the shower controls so it doesn't see anything but them/your hand moving.

The bigger question might be how do you turn it off? I like the vibration sensor on the shower head

If you have a shower door: use a door/window sensor (on the outside). Trigger the mood light if the door was open for only a couple of seconds.

Still more complicated than hitting a switch, tho, IMHO.

Vibration sensor that detects when water starts flowing through the shower head

I would go for a simple humidity sensor. You just need to do a bit of data collection first to get a baseline of "what taking a shower usually looks like" and then based on that create the automation.

The only problem with that is that depending on how accurate you want it to be, you may have to wait a while to take a few measurements until it triggers the automation.

For something like mood lights I would just use a ZigBee switch if I'm being honest though.

@batshit I use a derivative of a humidity sensor, it works well enough and is really simple to set up.

Would a battery powered smart switch be an option?

Hit the switch and let HA do a command series.

Any reason a flow sensor wouldn't work?

sounds like you could use a clapper

OK, assuming your switch is also smart

Option 1: long-press/double function turns on both light and fan, that triggers an "I am going to shower" 5 minute delay where a humidity sensor senses when it is over and keeps the fan on until humidity is stabilized with the rest of the house.

Option 2: get a smart flow meter instead of a smart valve. Then you have useful statistics for shower water usage in addition to an instantaneous status. This has the side effect of the mood lighting turning on "late"

Option 3: get one or make an esphome + LD2410S on battery or plugged in close by, nobody goes in the shower for more than like 10 seconds without showering

Option 4: Time of Flight sensor outside of the shower pointing in to tell when the door/curtain is closed. If the ToF sensor is (for example) between 1.1m and 1.2m, the door/curtain is closed