I have a grudge against the power save modes of the ATmega88. (Well ATmegaX8 really.)
Running on 8 MHz internal clock I try to schedule an ADC conversion every 0.1 seconds using Timer1 set to overflow at 3125 using a 1:256 prescaler.
I set the ADC to auto-trigger on Timer1 overflow and clear this flag again in the conversion-complete interrupt handler so it can re-trigger.
The timer just wraps around so it can trigger it's overflow again, keeping synch.
The problem is it looks like the power-save modes either doesn't allow me to use the Timer1 or triggers ADC conversion automatically upon entering sleep/halt.
Am I reading this correctly?
Any ideas on how to schedule this conversion so I can save as much power as possible inbetween handling each result?
Every 1 second (every 10'th sample) I will exit the interrupt and update my display before going back to sleep but other than that, not much is happening.