Saturday, February 19, 2011

Digital thermometers

I've been sick and didn't have much strength to think or write. But today I saw some of my chilli plants have sprouted (yeah, I also grow chillis) and I noticed that the temperature in the room was over 33 °C when there was sun shining.
And it got me thinking that every time that I want to do a temperature measurement, I have to look at the tiny LCD display of the digital thermometer, write down the temperature on a piece of paper, and then look at my watch and write down the time the temperature was taken. That's because I only have the cheapest thermometers available, those for $2 off ebay.

a cheap digital thermometer
This is so cheap, you should buy hundreds!

So I decided to do something about it. I want to modify one of these thermometers so I can connect it to my computer and record temperatures automatically. I am not sure how I'm going to do it yet. The most simple option would be to just connect it to the Line-In audio jack and then record the raw voltage input. A more advanced option would of course be the USB connector, but this will most likely require some kind of a driver.