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zephyr/samples/boards/nrf/system_off/README.rst

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samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
.. _nrf-system-off-sample:
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
samples: nrf: system_off: demonstrate use of device pm to reduce power Currently system power management does not automatically control device power, and this example demonstrates high current draw due to the UART being enabled. Enable device power management and demonstrate how to manually turn off greedy devices. Also remove the 60 s delay that confirms we successfully turned off the residency policy; that's not directly relevant to the purpose of the sample. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-05-21 00:11:53 +08:00
* Sleep for 2 seconds without device power control
* Sleep for 2 seconds after turning UART off, which reduces current draw
by a couple hundred uA
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
* Turn the system off after enabling wakeup through a button press
A power monitor will be able to distinguish among these states.
samples: nrf: system_off: show how to disable deep sleep Due to a long standing difference of requirements enabling deep sleep will by default cause any application that delays for an unbounded period to power down. On Nordic doing so turns the system off. Show how to prevent this from happening while still allowing deep sleep states to be available for the application's controlled use. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-07-01 22:46:32 +08:00
This sample also demonstrates the use of a :c:func:`SYS_INIT()` call to
disable the deep sleep functionality before the kernel starts, which
prevents the board from powering down during initialization of drivers
that use unbounded delays to wait for startup.
samples: nrf: system_off: add RAM retention example for nRF52 Add an object to retain data across both reboots and entry to SYSTEM_OFF. This only works on nRF52, since nRF51 and nRF53 require different low-level operations to configure RAM retention. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-02-02 06:42:52 +08:00
RAM Retention
=============
On nRF52 platforms this also can demonstrate RAM retention. By selecting
``CONFIG_APP_RETENTION=y`` state related to number of boots, number of times
system off was entered, and total uptime since initial power-on are retained
in a checksummed data structure. The POWER peripheral is configured to keep
the containing RAM section powered while in system-off mode.
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
Requirements
************
This application uses nRF51 DK or nRF52 DK board for the demo.
Building, Flashing and Running
******************************
.. zephyr-app-commands::
:zephyr-app: samples/boards/nrf52/system_off
boards: nrf52_pca10040: Rename to nrf52dk_nrf52832 The board name for the nRF52 DK, so far known as nrf52_pca10040, is renamed to nrf52dk_nrf52832. Its documentation and all references to its name in the tree are updated accordingly. Overlay and configuration files specific to this board are also renamed, to match the new board name. Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
2020-04-03 00:24:56 +08:00
:board: nrf52dk_nrf52832
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
:goals: build flash
:compact:
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
-----------------
.. code-block:: console
samples: nrf: system_off: demonstrate use of device pm to reduce power Currently system power management does not automatically control device power, and this example demonstrates high current draw due to the UART being enabled. Enable device power management and demonstrate how to manually turn off greedy devices. Also remove the 60 s delay that confirms we successfully turned off the residency policy; that's not directly relevant to the purpose of the sample. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-05-21 00:11:53 +08:00
*** Booting Zephyr OS build v2.3.0-rc1-204-g5f2eb85f728d ***
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
boards: nrf52_pca10040: Rename to nrf52dk_nrf52832 The board name for the nRF52 DK, so far known as nrf52_pca10040, is renamed to nrf52dk_nrf52832. Its documentation and all references to its name in the tree are updated accordingly. Overlay and configuration files specific to this board are also renamed, to match the new board name. Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
2020-04-03 00:24:56 +08:00
nrf52dk_nrf52832 system off demo
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
Busy-wait 2 s
samples: nrf: system_off: demonstrate use of device pm to reduce power Currently system power management does not automatically control device power, and this example demonstrates high current draw due to the UART being enabled. Enable device power management and demonstrate how to manually turn off greedy devices. Also remove the 60 s delay that confirms we successfully turned off the residency policy; that's not directly relevant to the purpose of the sample. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-05-21 00:11:53 +08:00
Busy-wait 2 s with UART off
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
Sleep 2 s
samples: nrf: system_off: demonstrate use of device pm to reduce power Currently system power management does not automatically control device power, and this example demonstrates high current draw due to the UART being enabled. Enable device power management and demonstrate how to manually turn off greedy devices. Also remove the 60 s delay that confirms we successfully turned off the residency policy; that's not directly relevant to the purpose of the sample. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-05-21 00:11:53 +08:00
Sleep 2 s with UART off
samples: nrf52: replace power_mgr with system_off The Nordic SOC doesn't support multiple system power states, only one deep sleep state. Replace the old example with a simpler one that can be used to measure CPU active, normal sleep, and system off modes. Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-11-19 08:08:08 +08:00
Entering system off; press BUTTON1 to restart