I've been reading about measuring battery level on Vcc for battery powered setups that don't use any step-up converter by comparing it to the internal 1.1V reference. (examples: http://forum.mysensors.org/topic/186/new-library-to-read-arduino-vcc-supply-level-without-resistors-for-battery-powered-sensor-nodes-that-do-not-use-a-voltage-regulator-but-connect-directly-to-the-batteries ; http://provideyourown.com/2012/secret-arduino-voltmeter-measure-battery-voltage/ )
My question. Is it possible to perform the same measurement to determine the voltage coming in on Vraw. I currently power my boards with 4AA's and use the onboard power regulator (http://forum.mysensors.org/topic/483/2-aa-batteries-with-step-up-converter-to-vcc-pin-vs-3-aa-batteries-to-raw-pin/23).