Starting from hardware side of things, all components were tested separately on breadboard. Putting all this together in a manageable package is just a bit of work.
The compnents used here are:
1x Arduino Duemilanove board
Playing with temperature sensors on breadboard is cool, but usually, if one has more than one sensor, one likes to get some distance between them.
These are no scientific tests, but in my real world application, LM35 likes shorter cables. The shorter the better, or it will get large fluctuations in measurements.
A cable about 3 meters is as long as I would go. Cable length of 5 meters got me into trouble. Consecutive readings did vary in more than 5 degrees. Not good.
Finally got this DS18B20 working. Actually three of them. And in two modes. Parasite power mode and main mode.
A 4.7K ohm resistor is the key.
Starting with the main mode, three wires are needed, as this sensor has three pins.
Datasheet is here http://datasheets.maxim-ic.com/en/ds/DS18B20.pdf.
Connection is almost simple.
Pin 1 to Arduino ground
Pin 2 to Arduino digital input
Pin 3 to Arduino 5V
And a 4.7K resistor between pin 2 and pin 3
Works with three wires, as seen on the followind illustration.
Checked out my local electronics store http://www.oomipood.ee yesterday and got some stuff.
First, a breadboard and some wires. Also got me a soldering iron. Those are just for testing. At least I do not have to twist wires together now.
Then I thought, LED-s are cool for something, right? There is a nice site http://www.ladyada.net/learn/arduino/lesson3.html. So I did get 10 1/4W 1K ohm resistors, and some leds, specifically 2 red, 2 blue and 2 green. 3mm and somewhere near 2000-4000 mcd.