nRF52840 - BLE advertising for minimum power consumption

[Nikosant03]

Hi everyone,

We are designing a low power PCB based on the nRF52840 BLE. At the moment the device is advertising with an interval of 1s and a timeout of 3min (advertising duration). I need your advice to optimize power consumption by minimizing advertising duration.

What I consider so far (see the flowchart below) is to initial start advertising while start-up, after time out expiration to stop advertising, and only in the case, that motion is detected by the internal accelerometer to start advertising again. I suppose that this is how a smartwatch could work in case that is forgotten somewhere / placed on the nightstand for the night etc. Is there any general industrial approach? 

[tesc]

Hi,

My impression is that using e.g. an accelerometer for activating a device on movement is a widespread technique.

Regarding advertising, the advertising module in our SDK supports five phases of advertising, which starts by rapid advertising to a specific device (directed advertising) for quick reconnection to a bonded device, and ends by long advertising interval before stopping advertising. Parameters and timeout thresholds are configurable. For an example using all advertising modes, see e.g. the HID Keyboard Application. Please note that for this example also uses whitelisting (only accepting connections from a given list of device addresses) if it has bonded to one or more devices already, and the example uses a button press for disabling this whitelist.

Regards,
Terje

[Nikosant03]

Thank you Tesk!!