I place this under the bed and as soon as you get up the sensor will detect motion and on comes the light.
This night light uses the popular PIR sensor to detect movement.
Then the ATtiny 2313 processes the signal and turns on the LED's for the set 2 minute, then off and waiting for another signal.
Repeat and repeat.
Step 1: ATtiny2313 vs ATtiny85
The ATtiny2313 has many more pins than this project could ever use. Over kill on the pin count.
That also makes it psychically bigger that say a ATtiny85. 20 pins instead of just 8.
It doesn't have the byte capacity of a ATtiny85. ATtiny2313 has 2K bytes verses the ATtiny85 8K bytes.
Like most everything it comes down to cost. The ATtiny2313 is the cheapest micro-processor i can get in my area, when shipping ect is factored in.
ATtiny2313 is $1.75 USD. Where as an ATtiny85 is $4.50 each if i buy 2.