SmartThings Pool Temperature Sensor on the Cheap

When your biggest burden is having to go outside to check the pool temperature, you know you need better problems. Previously, my biggest problem was wondering if I left the garage door open. That was easily solved by installing a Z-Wave Garage Door Opener. After some searching, I wasn’t satisfied with any of the solutions I came across for my pool conundrum. They either seemed cost prohibitive or unnecessarily complicated, so I decided to roll my own.

The SmartThings Multipurpose sensor is not waterproof. This put a damper on my plan of just tossing it into the pool. The day before I was talking with my co-worker about a cooking method known as ‘Sous Vide’, which gave me an idea. For the unenlightened, Sous Vide is a presumably french technique where food is vacuum sealed and cooked in a water bath to an exact temperature over a long period of time. My solution would involve vacuum sealing the sensor, and then placing it in the pool.

Sous ZiplocOn to the next issue, I don’t have a vacuum sealer. I decided to go the poor mans route and just use a Ziploc bags. I wanted to remove as much air as possible to keep the temperature accurate. I accomplished this by placing the sensor in the bag, and then submerging the back up to the zipper portion to force all of the air out. This seemed effective enough.

Once in the bag, I simply secured it in the pool skimmer. I don’t think this is optimal, and I’ll probably get some sort of floaty thermometer duck to tie it to the next time I’m at the pool store. Full disclaimer: I’ve only had this running for about 24 hours, attempt at your own risk.

Showing Temperature by Default in the SmartThings App

Pool is OPEN!Once all the hardware was in place, I noticed that when I first went into my dashboard, my pool status as open. It seems like the Multipurpose sensor defaults to open/closed with no way to change it in the current version of the app. Fortunately, SmartThings provides an API, and I was determined to show temperature by default to save that extra tap. If I have to make two taps, I might as well just walk outside and check the water.


SmartThings Sensor SettingsI was prepared to learn groovy, and create some sort of virtual tile to get this working. Luckily, I figured out you can just log into the SmartThings API and change your device type. The device was listed as ‘Smartsense Multi’ I tried changing the combo box to ‘SmartSense Temp/Humidity Sensor’ and it worked like a charm. Now there is an actual temperature/humidity sensor, but apparently it is hard to find. I’m guessing the pool’s humidity is 100%, so I’ll just keep it in the bag for now.

Cold Pool


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