I am working on home automation project.
In our project RF chip(microchip MRF24J40MB) is connected to the microcontroller atmel(atmega16).
RF chip is used to transmit the command from microcontroller via spi.
This whole unit is powered by battery.
If i press the switch of any bulb or fan the power ON the microcontroller and RF transmitter should transmit the command to the RF receiver placed on the receiver side.
Question is if i press the switch of any light or fan etc the MCU should be power ON otherwise MCU is OFF.
how i should design the circuit?
why i m worrying about this is i m using battery for powering, if battery is continuously ON the battery will last within an hour. How to solve this problem?
Which battery is better for this system?
NOTE : switch used here is capacitive touch switch .

 

Maybe a bit more info?
What are you trying to do?
What purpose is the RF chip?
Do you have a schematic, or a block diagram?