2 Overview

Many systems include one or more analog sensors that periodically must be checked. Analog sensors that generate voltage or current outputs are quite common. These signals can be measured using a microcontroller’s Analog-to-Digital Converter (ADC) peripheral. In battery-powered systems, it is crucial to minimize power consumption using techniques such as placing the microcontroller in a sleep mode between measurements.

This application note describes two examples of low-power analog sensor measurements using the AVR® EA family of microcontrollers. The first example demonstrates the use of a Resistance Temperature Detector (RTD) to measure temperature. The second example shows current measurement in a circuit using a sense resistor.