Waterproof temperature probe with pi zero

Hello, I’m building a low temperature incubator oven in an old esky for growing ‘koji’ culture on steamed rice - (for making miso). I am controlling the oven with a seedling heat matt driven by a raspberry pi and relay. I was going to use a small temp and humidity sensor on the wall of the esky but now realise i need a temperature (and maybe humidity) probe actually embedded in the steamed rice - because the temperature has to be quite precisely controlled between 30-40 degrees celsius. Cable needs to be less than a metre long.
Im programming this all with python (beginner / intermediate level). So would need a sensor i can read accurately with this. Is there a ‘one wire’ sensor that is inexpensive and easy to take readings from? Can you help me with any code libraries? I was looking at: Waterproof DS18B20 Digital temperature sensor + extras Australia
Or should I use the I2C model such as Waterproof DS18B20 Digital temperature sensor + extras Australia for ease of connecting and programming?
Looking to keep costs lower where possible, but will take the best option. I’m sure either of these will be better than the DHT11 sensor I started with, that was useless!
Many thanks for suggestions and code tips. Really appreciating what C.E is doing!


Hi Leo, welcome to the forum! :smiley:

Firstly, I assume your accidental posting of the same link twice was because this was the I2C sensor you were actually suggesting? It’s waterproof, does temp and humidity.

If not, that would be a great place to start.

There is also the following which is temp and humidity, not waterproof but the probe is stainless steel:

There are some good resources including sample code and library for it from DF Robot:



Thanks Matt, Yes not sure why the same link posted twice, my bad! The other was for a waterproof single wire probe like this:

Are the python libraries available to read these? Many thanks.


Looks like there are some Circuit Python libraries available here:


Thank you Matt!