basic temperature probe monitor?

I’m interested in monitoring the state of my fridges/freezers (I’m canadian, so I have a dedicated beer fridge) and wondering if there is a way to use a basic thermoprobe or thermistor. I see temp monitors that are around $60, but I wonder if there is a smaller (cheaper :slight_smile: ) probe that would be suitable.

You could probably do it for half that price, if you are happy to DIY it. There are digital temperature sensors such as the TMP102 or DS18B20 which you can communicate with over data bus protocols like I2C or One-Wire. To bridge the Vera to that protocol you could use a USB-aware microcontroller such as an Arduino. I’ve done this in my house, though admittedly not in the freezer (except briefly to test my negative-temperature conversion), so I didn’t need to deal with protecting the sensor from condensation.

If the above makes sense to you, then we can talk more about it. If not, then you are probably better off spending the extra on an existing product; to learn about programming microcontrollers and using I2C/One-Wire is going to take more than $60 of your time.

Just building on the idea of the 1-wire sensors such as the DS18B20 sugested by futzle, these are really good. I’ve purchased an EDS One Wire Server, which is an ethernet to 1-wire bridge - it’s not quite the cheapest way to do this at $100, but it works well, and is easier than messing with Arduino or PIC code. Once you have this, the DS18B20 is cheap and accurate and the OWServer will support up to 24 devices. Info is available here (OW-SERVER: 1-Wire to Ethernet Server, Revision 2).

I’ve written a plugin for the OWServer which will support the DS18B20 sensor and one of the EDS humidity/temp sensors - it’s easy to add other sensors in. Take a look at the thread,8381.0.html.