Alternative of mpsl radio notification API in NCS v2.6.0

[nms]

Hi,

MPSL radio notification API has been removed from the nRF Connect SDK v2.6.0. 

Is there any alternative way to get radio notifications?

Regards,

Narendra

[Vidar Berg]

Hi,

Yes, please have a look at the Bluetooth: Event Trigger sample.

Best regards,

Vidar

[pertan]

Hi Vidar,

I'm also looking for an alternative to the MPSL radio notification API in nRF Connect SDK v2.6.0+. More specifically, I'm relying on notifications fired some time before the radio turns on (MPSL_RADIO_NOTIFICATION_DISTANCE_420US). What is the equivalent API in nRF Connect SDK v2.6.0?

Thanks

[Vidar Berg]

Hi,

We currently do not have a direct replacement for this feature, unfortunately. Could you say a bit more about your use case for this signal? 

[pertan]

I'm using the signal to prepare and submit real time notification data for transmission. It is a time critical application, so I need to get the notification close to the connection event, but not too close since it takes some time to prepare and submit the outgoing data. This technique is described in this blog post. If there is no direct replacement, I'm interested to know what my options are for implementing this functionality myself.

[Vidar Berg]

Thank you for explaining the use case. I believe you can still use the connection event trigger for this. After initiating the connection event trigger, you could start a one-off timer, a delayable work item, or something similar to acquire the data and add it to the notification queue before the next connection event occurs.

[pertan]

If the delay mechanisms you suggest are sufficiently accurate, that sounds like a promising approach, given that the peripheral is aware of the current connection interval. Of course, there will be no notification before the first connection event after a connection has been established, but I can live with that.

[Vidar Berg]

Yes, the peripheral can check the current connection interval by calling bt_conn_get_info(). It can also register the le_param_updated callback to get notified if the connection parameters are updated. 

pertan said:

Of course, there will be no notification before the first connection event after a connection has been established, but I can live with that.

There are other packets that need to be exchanged at the beginning of the connection such the feature exchange, MTU negotiation, PHY update, etc that may also impact the timing. Notifications must also be enabled by client if it can't be restored from bonding information stored in flash.