@funky81 the original question was, if you could connect the supply to Vraw (using 3xAA batteries), and still use the internal Vref to calculate batteryvoltage. This is not possible Your approach is connecting battery directly to VCC on the atmega (bypassing the onboard voltage regulator). In this case it will work.

Ok. My primary problem was the radios I purchased form Ebay weren't the correct type. I've purchased new ones. Still got some problems to work through but I'll put in a seperate thread. For others reading later: Other references to these radios: http://forum.mysensors.org/topic/878/no-debug-data-from-sensors-or-gateway-bad-radios http://forum.mysensors.org/topic/728/radio-setup-give-check-wires/17 And specifically mentioned on the troubleshooting page as well.

@Zeph Thanks that is what I thought but I wanted to make sure :)

@Rek said: Does anyone have the spec sheet for the Chinese step up regulator? I bought a few of these to test http://www.pololu.com/product/2561 My guess is that it is or is similar to the 2108A in SOT89-3 described here: http://fullmany.com/Upload/file/ME2108%20series-E8_0.pdf