How to set nRF52840 to sleep and deep sleep for Zephir and Arduino?

[Claudio Rosa]

I am developing  a code for Nordic nRF52840 with some sensors:

1. LIS3DH: accelerometer
2. BME680: environment
3. Fujitsu MB85RC1M: FRAM
4. u-blox ZOE-M8: GNSS
5. SD Card reader
6. 4-20mA sensor + a pressure transducer

I already have a code in PlatformIO/Arduino BSP powered by 2 x LiPo 18650, but it is consuming too much power.  To fix this problems I found in some sensors a operation in low power, but not in sleep or deep sleep yet.

I am doing Nordic Academy trainning courses for Zephyr, but it will be a long way.

Could you help me with some way to put them in sleep or deep sleep mode?

Regards,

Claudio

[Kazi Afroza Sultana]

Hello,

Current consumption is a bit tricky as it depends on the peripherals and also devices of the board, other devices may need something different. The component of the nRF devices need to be in a state where they do not consume power; for example: disabling UART or some peripherals whose are not in use. You can look at this device power management Device Power Management (nordicsemi.com) document. 

If you want to use system off mode, you can look at these samples https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/samples/boards/nrf/system_off/README.html , zephyr/samples/boards/nordic/system_off at main · zephyrproject-rtos/zephyr · GitHub

[Claudio Rosa]

Hi Kazi,

The system off is one of last options because I will lost all data, for example in the GNSS sensor and  GNSS Almanaque send until 12 minutes to be created.  

When I say sleep I mean "reduce the power consumption" (go back with a warm process) and "deep sleep" (go back with a cold start) is "reduce as much as possible the power consumption,no matter if it will take more time to be ready.

Any documetation about it, I mean "sleep" and "deep sleep" guide lines for nRF52840 and their sensors?

Regards,

Claudio