One way to save power is to change the frequency the chip runs at
@@#include <io.h> ... /*
lpDelay(quarterSeconds) - Low Power Delay. Drops the system clock to its lowest setting and sleeps for 256*quarterSeconds milliseconds.
int lpDelay(int quarterSeconds) {
int oldClkPr = CLKPR; // save old system clock prescale CLKPR = 0x80; // Tell the AtMega we want to change the system clock CLKPR = 0x08; // 1/256 prescaler = 60KHz for a 16MHz crystal delay(quarterSeconds); // since the clock is slowed way down, delay(n) now acts like delay(n*256) CLKPR = 0x80; // Tell the AtMega we want to change the system clock CLKPR = oldClkPr; // Restore old system clock prescale
} @@ [1]
[1] http://www.reddit.com/r/arduino/comments/o5443/so_you_want_an_easy_way_to_save_power/