Hi folks, I wanted to see the temperature of the pool in Home Assistant so I bundled a few components together to realise my ahem … dream
To make the probe I used a Fibaro FGK-101 Zw5 Door / Window sensor which has connections inside for a DS18B20 temperature probe. I connected the probe, wrapped the door sensor in plastic to make it waterproof leaving the probe to dangle free. I put the whole lot in one of those floating chlorine dispensers made for swimming pools. They have holes in the bottom for the probe wire to go through. The whole thing floats around quite happily sending the temperature to HASS, I’ve set it to update every 15 minutes and after a couple of months the battery is still reporting 100%.
Eventually I think I’ll seal the door sensor in a small waterproof box and fix it under the edge of the pool with the probe dangling in the water but my proof of concept works.
Can you please share some pics?
I’m looking for a pool temperature sensor for s long time. Your design makes a lot of sense and seems not to difficult.
That sounds easy enough to do.
I assume you did not find a temperature sensor all by itself then.
I’ve been trying to find something to use as a remote thermometer but the ‘unnecessary’ door/window sensor sounds like the way to go.
Hi all, I’ll take some pics this weekend. It was super easy to put this thing together. I wanted something battery operated and wireless that wasn’t going to need the battery changed all the time this solution does the trick.
OK Gentlemen and Ladies, sorry for the delay in replying. After disassembling my pool probe to take pictures I decided it was time to improve it a little. Originally the Fibaro was in several layers of freezer bags, each individually tie wrapped to all allow the wire to protrude, however of course over time they start to leak so I came up with an idea to make the sensor a bit more robust.
This is the probe in the pool, the chlorine dispenser is way too big in fact but I imagined the Fibaro sensor was bigger when I ordered it. You can see the probe floating in the water below, it doesn’t need to dangle so far but I was testing for the ideal depth, in my case the water is well mixed so depth didn’t really matter.
Now I’m just waiting for the silicone to cure both on the inside and the outside of the cap. I will also silicone the cap into place before the whole unit goes back in the floater. As the battery seems to be holding up well (still reading 100% after >2 months) I don’t mind breaking the seal and resealing the unit when the battery needs to be changed.
Eventually I’ll fix the sensor under the pool margin stones, once I find a suitable box to put it in that doesn’t look out of place in a pool. I guess you could also place the probe in the filter intake pipe.
Alternative hacks I considered:
An ESP8266 with a DS18B20 temperature probe. I ruled this out because I wanted a battery operated system and the ESP is quite power hungry and I don’t have the skills to write some complex code to get around this.
An ESP8266 with a DS18B20 temperature probe and a solar cell on top of the chlorine diffuser to charge a battery. This would be a cool project that I might try one day.
A Fibaro Universal Sensor - looks great but probably needs to be attached to a power supply for the 9-30v DC it requires. I didn’t calculate battery life for this sensor.
This looks nice, I’d probably recommend tossing one of those silica gel moisture packets inside the tube just to keep the fibaro nice and dry from temperature changes and humidity ingress.
Hi, thanks for posting this, it is exactly what i had been looking for. I have managed build it and connected it to my HA system running on an rPi.
I have found that the reading does not update though until there is a significant change in tempreture. I can leave it in the pool for days on end and it will continue to read the same temp, but when i remove the sensor from the pool, within a few mins the reading will update and then when i bring the sensor inside the house (air conditioned) it will update again after a few mins.
Has anyone else come across this issue?
Thanks in advance for your assistance.
Yes I had the same problem, I changed a setting for the sensor and got it to update every 15 minutes. It was a bit tricky. When I get chance I’ll try and retrace my steps and let you know.
My pool is about 50 feet from my house do you think zwave would work? I could maybe put a zwave switch in my shed but that would still be 50-60 feet away.
With my setup I get a range of about 50 feet (max) with the receiver in the house and even then I get the occasional missed reading when the sensor has floated to the far end of the pool. Z-wave can mesh with other z-wave devices so that might help. It also depends on the structure of your house.
Yes, this is common for battery powered devices. To speed things up you can manually wake the sensor up by quickly pressing one of the tamper buttons three times, that will transfer your new settings to the device.
One of the settings is the update interval, try fiddling a bit with that too find an update frequency that works for you.
Pretty sure the Fibaro sensors do not update by default unless the temperature delta changes significantly (I think the default is 2 degrees C) Ot can be changed to auto-report every x number of minutes, but that tends to drain the battery considerably. One consideration might be to determine just what type of temperature monitoring you wish you be doing. Do you need to know the exact temperature every 15 minutes? Or would adjusting the default from say 2 degrees to a single degree be sufficient to keep good track of your pools temperature. Overall just keep that in mind when considering battery life.
Apologies for bumping an old thread, but this looks like something I can take on as part of my learning of home assistant.
As this is my first post, this may be a really basic question, but if I’ve got my server running on a RPi3 and I’ve managed to setup a couple of simple lifx devices so I know I’m on the right path.
If I have the 2 components listed, do I need to also have a Z-Wave hub to allow the sensor to communicate back to the software? If yes, any recommendations for a cost effective device for this?
I’m ordering one from Amazon.com to Toronto, its about CA$70 with import fees and shipping (link). Expensive for sure, but, it’s such a nice setup vs other ways of doing this.
