Setup of Temperature Sensor for Pool

Hardware
1

Hi,
not sure if thats the right place for suchz a question but I want to get the water temperature of our outdoor pool.
Thought about using an esp32 running esphome to integratre into home assistant.

Sensor would probably be the ds18b20 like this one.
A USB-C ESP32 like this one (I noticed there also other one micro USB-B one, are there any advantages/ disadvantages) and some generic breadboard as I would rather not solder (maybe at a later point).
Also a 4,7k ohm resistor is needed (https://www.amazon.de/Widerstand-Stück-Metallschicht-Metallfilm-Widerstände/dp/B00I8NOOEY)

Then wire it up like this:
image

I just want to be sure that this all works out and Im not missing something or if there is another better option out there. It needs to be waterproof (or have a waterproof extension), obviously work with home assistant and best would be wifi because I have not zigbee/z-wave coverage there (but wifi is plenty).

Would appreciate some confirmation/ feedback by you guys as this would be my first “diy” sensor and im also not really familiar with circuits, bread boards and so on…

2

Yes, those are all the parts you need. Check this out if tou need some inspiration on how to mount the temperature sensor in the pool: Smarter Swimming Pool 2: Water Temperature – neon.ninja
I have since migrated this sensor to ESPHome, but the wiring and mounting is still the same.

ESP with USB-C vs micro USB: Does not make any difference other than the power cable used.

1 Like
3

Thanks man.
Not quite sure where to mount the sensor yet but have already a few spots in mind.

4

What type of pool do you have? Chlorine I guess? Its salt for me.
Just came into my mind that submerging metal into a salt water pool over a long peroid of time is not such a good idea.
I stumbled upon a different version of the ds18b20 which does not have a metal cap: Amazon.de (SEN-11050 ). Although it is way more expensive

5

Yes, it’s chlorine.

Not sure. I had to replace my sensor once after about 5 years. I think the metal tip is made of stainless steel, so it might survive a salt pool?

That might be a good option as well. It says it’s sealed, so would be interesting to see how long the seal and plastic survives in salt water or chlorine.

6

Sadly only found a 2m version of the sensor which is probably to short.
Will see and report what I chose and how its going.

7

You probably can’t buy them any longer but you can extend the cable yourself.

8

What would you recommend for extending? Rj45 cable?

9

For short extensions (like a couple of metres) I have used simple 3-core shielded wire about 20AWG diameter.
I haven’t used RJ45 myself for such extensions, but I remember people on this forum reporting they successfully used RJ45 over longer distances for similar sensors.

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