Hi everyone,
I am desing a low power BLE application using the nRF52840.
How do I restart the advertising after the APP_ADV_DURATION has been expired?
Thanks in advance
Nick
Hi everyone,
I am desing a low power BLE application using the nRF52840.
How do I restart the advertising after the APP_ADV_DURATION has been expired?
Thanks in advance
Nick
Hello Nick,
Nikosant03 said:Thank you for your prompt response!!
No problem at all, I am happy to help 
Nikosant03 said:I design a wearable that is going to be connected with a smart phone.. So what is the general approach that is followed? I have to set the wearable to advertise it self without time out in order to be connected with the central?
I can not speak for the industry general approach - because this varies with the needs of the different products - but the main consideration with regards to advertising duration is the power consumption.
A device that does not time out will continue advertising until the battery is drained ( or a connection is made ) which will cause an unconnected device to drain a lot faster.
I am not familiar with the use case in this particular case, but it is a balance between "always auto connecting immediately when possible" and power consumption.
A power efficient approach could have the device advertise for a given interval following powerup or button press, and then stop advertising until the button is pressed again or until the device is shaken / moved / external change - depending on what other peripherals you have available.
If you would like to get some estimates for how much the added advertising affects power consumption I highly recommend checking out our Online Power Profiler.
Nikosant03 said:Imagine a smart watch and a smartphone.. In general when tha smart phone is within the range of the smart watch they are connected automatically.. So I guess that the smart watch is advertising is self without a time out until to establish a connection with the central. I am looking for a solution with the less power consumption.. Any general advice?
I do not know exactly how this is implemented in the "industry standard", but I cant imagine that it is always advertising - perhaps it is implemented like I mention above, it goes into low power mode when no movement is registered, and it starts advertising again / goes high power mode when the accelerometer registers movement. I imagine this would be the wanted behavior, in case the watch is forgotten somewhere / placed on the nightstand for the night etc. You would like it to do only the bare minimum to conserve battery power when not in active use. But as I said, this is more of a qualified guess than actual wearable industry insight on my part. If you would like to go more in depth with your wearable discussion ( leaving the advertising restarting issue of the original ticket ) I would ask that you open a new ticket with this as the issue, so that you may be put in contact with one of our engineers with more wearable industry experience - and that the forum remains searchable.
To conclude my long answer to your general advice question: Check out the power profiler to estimate how much power consumption is increased by decreasing advertising intervals / always advertise.
Please do not hesitate to open another ticket if you should encounter any more questions or issues!
I hope you have a great day, Nick!
Best regards,
Karl
