electronics control system block diagram
Wel the block diagram is basically for temperature controller in which one can set (through key board)minimum and max temperature as per requirement. If the temp is out of this window (min,max) a lamp is used to indicate the status and action can be taken like fan ON or OFF.
What u can add.
1. U can add a RTC chip to give you present date time etc or u can write a program to calculate all this.
2. U can add a memory chip to store the temperature readout after perticular time of interval, maintisning a time and corrosping temperature in a memory.
3. U can set this time thro keyboard.
4. U can add a feature --- like to count the number that this many times in a day or 24 hrs (lets assume a day here) the temperature readout was out of given window..etc