I started my smart home journey many years ago. I’m definitely not a seasoned expert, but literally a user who tries a lot with my own smart home project and fails even a lot more 
A room which I found super-challenging to manage to get it smart enough (to fit my satisfaction) is the bathroom.
In my case, the bathroom is very small, only 1.6m (Length) x 1.8m (Width) x 2.3m (Height), or approximately 5.3" x 5.9" x 7.6". With every bathroom essential components like a toilet, basin, and shower inside this pathetic bathroom.
Device List:
- 1 x Aqara Hub M2
- 1 x Aqara FP2
- 2 x Aqara High Precision PIR Motion Sensor
- 2 x Aqara T1 Switch Module with Neutral
- 2 x Aqara Contact Sensor
Automation Rules:
My goal to make this bathroom smart are automating lighting and ventilation (exhaust fan) for any bathroom circumstances, for example, when using toilet 
, when showering 
, when doing some sus business 
, or anything. The light has to turn on automatically when someone gets inside, and has to stay on as long as they’re inside the room, and the exhaust fan has to run all the time when someone’s in the room to keep it well ventilated. And they have to be turned off shortly after someone gets out of the room.
But there’s a special circumstance, showering. This is when the scenes (on the Aqara app) come into play. After showering, the exhaust fan has to run 10 more minutes after my shower valve shuts off to reduce moisture or steam that builds up in the room. With this showering circumstance, the light turns off shortly after I leave the room, but the exhaust fan will continue running [it will ignore the automation I mentioned above in this special (showering) circumstance]. It not only helps reduce the steam and humidity (even though it doesn’t help with humidity much for just 10 minutes of running fan), but something that’s clearly improved are tVOC and CO2 (tVOC and CO2 sensors are not parts of this automation but I usually read the values they collect) inside the bathroom and my living room (which is connected to the bathroom). So this solution is like a daily active ventilating time for my house whenever I take a shower (usually twice a day since the weather is too hot here in SEA.).
Note:
Vent = Exhaust Fan (Ventilation Fan)
PIRs = Aqara High Precision PIR Motion Sensors
mmWave = Aqara FP2
Device Breakdowns:
I have to admit that it might be overengineered and has a lot of redundancy (there might be any other way that is more effective and budget-friendly to get the same result), but since I struggled a lot in the past to get my bathroom smart, so I put whatever resources I have into that room to my it perfectly automated according to my needs. Let me break down which devices are used for a specific thing.
Some devices, especially the FP2 and the High Precision PIR, are used in conjunction in many cases to make a more seamless automation experience.
Note: BL = Bathroom Ligt
- 1 x Aqara Hub M2 for the brain of automation.
- 1 x Aqara FP2 used to detect human presence. To get the exhaust fan running. To get it light on.
- 2 x Aqara High Precision PIR Motion Sensor used to detect a quick motion (as you may know, the PIR is a bit faster to detect occupancy) so I used it to get the light on when detects motion, and to cross-check with the FP2 in case the FP2 fails to detect absence, these Aqara High Precision PIR Motion Sensors will get the light off automatically. The reasons I use this High Precision Motion Sensor model particularly (not the original Aqara PIR or the P1 or P2) are that it is very sensitive and precise with a very quick detection interval.
- 2 x Aqara Contact Sensor
The first one is attached to the bathroom door to automate the lighting to be on instantly when the door is opened (to get the lights off, I use the FP2 Presence Sensor exit detection).
Another Aqara Contact Sensor is used for detecting my shower valve status. It’s a retrofitted solution that looks quite ugly. I coated the contact sensor with a light silicone layer to ensure it can prevent water ingress a bit better, since it has to be exposed directly to water. It’s been working great for 2 years now.
- 2 x Aqara T1 Switch Module with Neutral used to control my LED bulb (dumb bulb) and the exhaust fan.
That’s all for today! This automation has been working well for 2 years and is continuing. I hope I’ll never have to do anything with bathroom automation again, but seems unlikely if there’s some new tech or if I have some new ideas. Thanks for your long reading!
, so let it rock on Aqara Home in a while.