Little Bird Electronics posted an article about using an analog voltage reference with Arduino. This is a tool available when using an analog-to-digital converter. By setting up either an internal ...

When one of them is pressed, it completes the circuit for a voltage divider. The results are measured by the analog-to-digital converter of an IC to tell which button was pressed.

This high-efficiency IC with charge pumps and associated circuits reduces input voltage up to one-eighth while providing a 15-W drive for external point-of-load regulators.