Controlled number of advertising packets

[Siddhesh]

Hi,
We are using the SDK v17.1.0 and SD S140 v7.2.0. In our application we have to send only 1 advertising packet with updated data every 300ms and in some cases every 50ms for synchronization purposes.
We have a periodic timer which starts and stops advertising at these intervals. 
So the flow goes as follows Start advertising -> timer expires -> Stop advertising -> update data -> Start advertising.

We are using the following intervals and timeouts for the 2 cases
300ms case
Adv interval 280ms Adv Timeout 5s
50ms case
Adv interval 40ms Adv Timeout 5s.

However we are not seeing any packets being advertised from the device with this scheme. Does ble_advertising_start not send a packet immediately after it is called ?
Is there a better way to ensure that only one packet is sent on every call to ble _advertising_start ?

This device is a multi-role device. It is also acting as a central and scanning continuously. Could that have an effect on the radio ?

[Vidar Berg]

Hi,

It's strange that you don't see the advertisements after updating the payload. Do you check for errors when you call advertising update and start? Note that you can also update the payload on the fly as explained in this blog post: https://devzone.nordicsemi.com/guides/short-range-guides/b/bluetooth-low-energy/posts/how-to-update-advertising-data-dynamically-using-ble-advertising-library?CommentId=a03b6f8d-71bf-4481-b6fb-7b1fea3a8357 (only payload - advertising must be stopped if you need to change adv. parameters as well)

EDIT:

This device is a multi-role device. It is also acting as a central and scanning continuously. Could that have an effect on the radio ?

sd_ble_gap_adv_start() will return with NRF_ERROR_RESOURCS if the stack is too busy performing scanning and maintaining other connections. In that case, you may try du reduce the scan windows.

Best regards,

Vidar