Introduction: How and Why to Use the Arduino ADC Internal Reference
In this Instructable we look at the ADC internal reference in an Arduino, why / when would you use it, how to ensure you get good measurement accuracy when using it, and how to use it to check your battery voltage. You can find the code on my blog at http://forcetronic.blogspot.com/2016/01/utilizing-arduino-adc-internal-reference.html