Its fair to say I have used a lot of micro controllers, and over the years an Arduino in some form or another has crept its way into many of rigs and prototypes I make. They are cheap, reliable enough and support an army of open source contributors. However, I have rarely had work within a power budget as typically they end up tethered to a laptop gathering data or interacting with a wider system that can have its own supply. 

This changed when I started designing a battery powered outdoor weather station, I turned to a staple microcontroller the “Arduino Nano”, as its brain. Measuring the current consumption of an off the shelf board indicated the hungry PCB would gobble up an AA battery in just a couple of days. 

After a round of trail and error with power saving techniques, I was able to significantly improve the original system battery life, so much so that I have compiled my findings here for future reference. Therefore I have detailed below a series of steps that you can take to incrementally reduce this particular microcontrollers power consumption.