Deep sleep mode for the Uno without complicated circuits? so I'm building something using an Uno that will run on batteries - so, I've watched a couple of these low power tutorials to lessen the energy consumption so the batteries can last longer, but they're not exactly what I want - they all require some sort of circuit. I've found this tutorial (http://www.engblaze.com/hush-little-microprocessor-avr-and-arduino-sleep-mode-basics/) which only needs an LED, and it's ideal, but I would like to know if you know of any other methods which would reduce consumption to less than 5mA without using any complicated circuits (other than unplugging the Uno)

Thank you!
Deep sleep mode for the Uno without complicated circuits?


Forget using an Arduino Uno if you want to do low power (less than 10 mA standby). There is too much extra circuits (LEDs, Voltage Regulators, etc) to allow that. 

See for instance, https://www.gammon.com.au/forum/?id=11497

With an Arduino Pro Mini it is possible to achieve low power after removing the Power LED and cutting the Voltage Regulator.

The hardware/software support for low power cannot really be used before the board is design for that. 

Cheers!