My garden light is a simple $1 type that has a light sensor to tell it when to turn on the LED.
typically comes on and sunset and the battery is typically dead by the time it gets dark.
I was thinking of adding a ATTINY and add two features.
one is to use the ADC to actually measure the LDR
the second would be to add hours of delay.
the idea is that with three of these garden lights, one coming on at nightfall, one sometime in the middle of the night and one coming on very late... the path can be lit all night.
the primary goal is to add the delay of a couple hours.
timing is not critcial, a couple hours after nightfall and not so quicly. seems they come on at dusk.
as for what I need help with. power.
If I use a single AA battery, running a ATTINY is iffy. I might be able make it a series AA battery unit.
since it will run at a native frequency, I will not need an external crystal and since timing starts at twilight, I do not expect any issues with times.
I will sleep most of the time, wake every 15 minutes, look to see if anything changed, then either react or go back to sleep.