Author: Rupali Honrao, Microchip Inc.

The Microchip tinyAVR® 0- and 1-series, and megaAVR® 0-series controller offers an Analog-to-Digital Converter with 10-bit resolution. In most cases, 10-bit resolution is sufficient, but in some cases, higher accuracy is desired. Special signal processing techniques can be used to improve the resolution of the measurement. By using a method called ‘Oversampling and Decimation’, higher resolution might be achieved without using an external ADC. For example, by using 10-bit ADC, a 12-bit result could be achieved with oversampling technique. This application note explains the method and conditions needed to be fulfilled to make this method work properly. This application note also provides source code according to the explained theory to achieve this oversampling technique.