nRF5x System Off demo

Overview

This sample can be used for basic power measurement and as an example of deep sleep on Nordic platforms. The functional behavior is:

  • Busy-wait for 2 seconds

  • Sleep for 2 seconds

  • Sleep for a duration that would, by policy, cause the system to power off if the deep sleep state was not disabled

  • Turn the system off after enabling wakeup through a button press

A power monitor will be able to distinguish among these states.

Requirements

This application uses nRF51 DK or nRF52 DK board for the demo.

Building, Flashing and Running

west build -b nrf52_pca10040 samples/boards/nrf52/system_off
west flash

Running:

  1. Open UART terminal.

  2. Power Cycle Device.

  3. Device will demonstrate two activity levels which can be measured.

  4. Device will demonstrate long sleep at minimal non-off power.

  5. Device will turn itself off using deep sleep state 1. Press Button 1 to wake the device and restart the application as if it had been powered back on.

Sample Output

nRF52 core output

***** Booting Zephyr OS build v2.1.0-rc1-158-gb642e1a96d17 *****

nrf52_pca10040 system off demo
Busy-wait 2 s
Sleep 2 s
Sleep 60000 ms (deep sleep minimum)
Entering system off; press BUTTON1 to restart