Need suggestions for Raspberry Pi temperature sensing

[Lynchy217]

Hi, So I've been working on developing my own Raspberry Pi temperature controller. I'm currently using a Off the shelf PID controller with a PT100 probe. I looked into using the probe with a Raspberry Pi, but the more I look into it, the more annoying it seems. I was hoping for an off the shelf bridge between the PT100 and the Raspberry Pi, but I haven't really found any. Are there any easy to use sensors out there that work with Pi off the bat? I've found a few single wire solutions, but none of them are water proof. I was hoping for a probe that could fit a 1/2" NPT connection, since I already have a hole in my kettle for one.

I am an EE, so I could make the RTD work, but it seems like it's going to be far uglier if I do it on my own rather than just buying something that works off the shelf.

Any suggestions would be fantastic. Thanks guys!

 

[doug293cz]

How about this one: https://store.brewpi.com/temperature-sensors/threaded-onewire-temperature-sensor

Brew on

 

[pablosbrewing]

And another with stainless braid cable and metal shell connector:
http://www.auberins.com/index.php?main_page=product_info&products_id=322

 

[BlkWater_brewer]

You can get waterproof DS18B20 One-Wire connectors dirt cheap. The last I bought were 5 for $9. Or you can by a DS18B20 chip for about $2.50 attach your own wire and use a thermowell. These are what are used in almost all of the Raspberry Pi type controllers.

 

[bheinecke]

There are a number of variations of the DS18B20 which are waterproof and compatible with brewing (like the link from doug).

I am personally working with arduino and got a batch of 5 these sensors from amazon for ~$20 with 2 meter leads (added food grade heat shink because i don't know what material the mfg used to make it water proof).

Arduino is 5v and I have 5 of these sensors with a single 470k resistor between the data wire and +5v. The code is also pretty straight forward in c++. I would assume it is also easy for the Pi (python?). Quoting from the data sheet:
"Can Be Powered from Data Line; Power Supply Range is 3.0V to 5.5V"

I have also run temperature tests in ice water and at boil. The 5 sensors are within 0.5degF of each other. They are all also within 0.5degF of my therma pen which is certified within 0.7degF. Soooo.... they are pretty good.

 

[Lynchy217]

There are a number of variations of the DS18B20 which are waterproof and compatible with brewing (like the link from doug).

I am personally working with arduino and got a batch of 5 these sensors from amazon for ~$20 with 2 meter leads (added food grade heat shink because i don't know what material the mfg used to make it water proof).

Arduino is 5v and I have 5 of these sensors with a single 470k resistor between the data wire and +5v. The code is also pretty straight forward in c++. I would assume it is also easy for the Pi (python?). Quoting from the data sheet:
"Can Be Powered from Data Line; Power Supply Range is 3.0V to 5.5V"

I have also run temperature tests in ice water and at boil. The 5 sensors are within 0.5degF of each other. They are all also within 0.5degF of my therma pen which is certified within 0.7degF. Soooo.... they are pretty good.

This sounds pretty good.I'm either going to use Java or a combination of Python and C++ (Python for communication and display, C++ for the lower level stuff.) At this point I'm leaning towards Java only because I want to eventually communicate with it using an android device, which use Java. as of right now, I'm thinking about getting the brew pi one, since it's pretty easy to add to my current setup and I can take the measurements in the tube if I need to. Thanks for the help guys, this has been really useful!

 

[PGEduardo]

Good info here. Need to get off my ... and do this too.

 

[FamilyTradition]

You can get waterproof DS18B20 One-Wire connectors dirt cheap. The last I bought were 5 for $9. Or you can by a DS18B20 chip for about $2.50 attach your own wire and use a thermowell. These are what are used in almost all of the Raspberry Pi type controllers.

Beware of these I have going through about 5 of them looking for something else, might try a braided stainless one