Switching nrf52 on/off - industry best practice

[okay_-_computer]

What is the industry best practice for controlling the on/off state of an nrf52 using a momentary push button? Do designers use nrf’s deep sleep mode or properly cut off power from the battery using a transistor latch? How is this usually done? I've spent days googling, and have not found a singular answer. 

[Michal]

Hello,

It all depends on your use-case. The simplest way (hardware-wise) is of course to use our SYSTEM OFF sleep mode with external GPIO wake-up. Using a button connected to the nRF device may also allow you to do some gentle shutdown if needed.

If you need your device to use even less current (or want to switch off much more), then either using a transistor latch or a dedicated power management/load switch IC with a momentary switch support may be a better idea.

Best regards,

Michal

[okay_-_computer]

Can you show me a schematic which shows how this should be implemented? I haven't found any online example showing this (maybe because it's too simple for anyone to ask about??) but that's what's stopped me from going through with this design. 

[Michal]

Which of the methods exactly?

[okay_-_computer]

This way:

"The simplest way (hardware-wise) is of course to use our SYSTEM OFF sleep mode with external GPIO wake-up. Using a button connected to the nRF device may also allow you to do some gentle shutdown if needed."

[Simonr]

Hi

We have a system off sample in Zephyr available here that you can use for reference of how to go into system OFF mode. There is no need to do any changes to HW to set system OFF sleep mode. Generally using the system off sleep mode is sufficient, but it varies a bit from use case to use case.

Best regards,

Simon