Hi all. I would like to run an 328P at low power, will it be OK running from 3x AA batteries? At what voltage is it likely to stop running?
If I used the internal 8MHz clock, would that improve consumption much? I want to make a IR remote control, will running at 8Mhz screw the sketch up - timings etc?
If you put an 8 MHz bootloader into the part, the timing aspects should be accounted for already. For example, the Promini 3.3V 8 MHz. Will run fine at 4.5V from 3 batteries. I have an RF remote control uses 3.3V 8 MHz Promini, I run it from a 3.7-4.2V LiPo battery. I used a 3 AA battery pack for initial development.
The 328P still runs with 1.8V (low-voltage shutdown = brown-out-detection disabled or set to 1.8V). So 3 AAs would be fine. When you put it to sleep you can decrease supply current to less than 1 microampere if you switch everything off (think about how you want to wake the controller up again).