I was reading about the power optimization on the page,http://openenergymonitor.org/emon/node/115. I have tried a bunch of different power saving methods but I am unable to get my atmega328P to work with 3volts. Only, 3.3 volts. I am wondering if it could be the bootloader or if it is something else not mentioned in the article?
Thanks,
Dawn.
Re: Power Optimization for the Atmega328P
Hi Dawn,
It should work down to 2.7V without any modification. At 2.7V the BOD (Brown out detection) will cut in and the chip will shut down. The BOD can be reduced or even removed altogether by changing the internal re-flashable fuses. You will need an ISP programmer (or another Arduino) to do this, see: http://nathan.chantrell.net/20120107/further-extending-the-temptx-battery-life/.
The JeeLib library has got a built in sleep function, we use it in the emonTx firmware. It's essential to use this to out the ATmega to sleep in between readings to obtain any sort of low power operation. Bear in mind that operating at 16Mhz and 3.3V and below is essentially overclocking the chip, we've never had trouble with this, but maybe you have a chip which does not like this. There is lots of information about the various sleep functions and low power opperation on the ATmega if you google.
All the best,
Glyn.