Example Overview

The example project aims to show how to achieve a very low average power consumption when sampling a sequence of three inputs 32 times per second. The RTC is used to generate events, initiating each conversion sequence. The three individual samples are transferred from the result register to RAM using DMA. The application can operate in either active mode or sleep mode, controlled with a button on the board. In active mode, USART communication is enabled to transmit the latest ADC samples to a COM port on the connected computer. In sleep mode the RTC, ADC, and DMA will continue to operate as sleepwalking tasks.

Figure 1. Application Schematic

The configurations and most important implementations from the example project are descriped and shown in this section. Firstly, the actions needed to achieve the low power consumption are presented. Secondly, peripheral configurations are described. Refer to the related example project for the complete implementation.

More details regarding the SAM L-series low-power features and techniques can be found in the following application notes:
1 http://www.atmel.com/Images/Atmel-42411-Ultra-Low-Power-Techniques-AT06549_Application-Note.pdf
2 http://www.atmel.com/Images/Atmel-42412-Understanding-Performance-Levels-and-Power-Domains-AT04296_Application-Note.pdf