temperature control with LM35 and 2x16 lcd

Hi Guys I want to make a temperature control and found this one to try learn from can someone help in pointing to the right place to learn to add set points and some hysteresis etc. Do I need a state machine ?

http://circuits4you.com/arduino-temperature-controller/

thanks

Do I need a state machine ?

No, just some basic logic -

i.e. If the temperature is below 70 degrees F, turn the heater on. If the temperature is above 71 degrees, turn it off.

You can add more logic with AND and OR conditions if you want to add a clock/timer or air conditioning controls, etc.

Hi You can do better than that really. I've searched every where and cannot find anything to help with setting set points for temperature and to add hysteresis. Wheres Mr Nick G ?

john