Archived Forum

I monitor my heating with 1wire DS18B20 sensors which I mounted on the pipes. They are really cheap. I then use a 1wire Host USB Adapater on a RPI as the GPIO variant is to weak for more than 12 such sensors. 

I have this stuff ordered from sheepwalk electronics:

- USB Adapter http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=22&products_id=29 works great on windows and RPI's

- DS18B20 Temp sensors: http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=24&products_id=37 if you want to solder everything your own like me or finished products like this: http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=23&products_id=52

You can use their hubs to create a big network. Just make sure that you use a 5V power source for longer distances. The max wire length is 300m in my installation where I have routed a network cable to my external shed  :-) 

Of course you can also use an EMonTH with an external DS18B20 connected if you want to do it via radio and do not want to use wires. It's of course a little bit more expensive

You can see me heating here: http://swiss-solar-log.ch:85/firefox&id=85  It's a simple dashboard just showing the most important stuff. To read out the 1wire Temp sensors you can use node-red for example. It already has a node which connects to the OWFS server on the RPI. I do it like this in my house. I have 3 RPI's with each a own 1wire USB Host. I have 4 levels in my house so it's easier to have floor networks instead to route everything through the building.

I'm sure others will come up with other solutions. I just went the 1wire way because it has a lot of other options like PIRs, Humidity, Door and Window contacts which you can implement and you just need 1 small cable for that. In fact all the sensor should be on the same single wire but in my case that was not possible so I just use a RPI per floor :-)