Monday, November 25th, 2013 at 8:24 pm
Ten years ago I purchased a couple of DS18S20 1-Wire temperature sensors to monitor the outdoor temperature, the ambient room temperature and the temperature inside my computers. Along with the sensors themselves I got a RS-232 to 1-Wire adapter and a DS1820 mounted on a demo board.
While I did connect them up and used DigiTemp to prove that the adapter and sensors worked. I didn’t get much further, until two months ago when I decided it was about time to do something related to home automation, the result being this:
After a failed attempt at using an old serial port header to connect the RS-232 adapter I splurged on an entire $6 to get a bright pink USB to RS-232 adapter. The remainder of the hardware pictured is the DS9097U-009 adapter and the demp DS1820 mounted at the end of an RJ11 cable.
The software side consists of the digitemp package, a wrapper to pull the temperature from the digitemp output, and my existing MRTG setup.
Since then this setup has been logging the temperature every five minutes. It was interesting to be able to see my central heating come on at 5pm and cycling to maintain a target temperature of 20°C until 11:45pm. The above snapshot shows the central heating coming on yesterday, but not on the current day.
Despite this now being in use for almost two months, my plan is to incorporate the sensors into something more sophisticated, for example an Arduino based ethernet connected thermostat for my central heating. This is not a new idea, there are just a couple of examples floating around to use for inspiration.