I took one of my Jimmy Rodgers heart kits - gussied it up with some silk flower petals - hooked it to an older Adafruit Boarduino and gave it to my honey for Valentines. I used 3 dollar store AA's as power. She put it up on the Mantel and there it sits - for a week now - happily blinking away. I am astonished at how long the batteries are lasting - she is loving the gift I made her. I guess we are both happy.