One Central multi Peripheral connection problem

[helen]

Hi

         1、 I want to know the connection mechanism of one Central connects multi Peripheral.

         2、What is the time interval between one connection switching to another? Is there a flow chart？

         3、How to ensure that the data of a link is sent before entering the next link?

thank you

[Karl Ylvisaker]

Hello Helen,

The SoftDevice will take care of all this for you, and schedule the different connection's into different timeslots where they will be handled separately. The application layer will not need to worry about switching to an upcoming device in time, or that the link's connection event will be cut short.
If you intend to use Connection Event Length Extension you could read about that in its own section in the documentation, Figure 1 of this section also explains how multiple connections are scheduled one after the other.

Best regards,
Karl

[helen]

Hi 

          Whether there is a response mechanism between the center and peripheral after connecting, If so，Why does data loss occur?

[Karl Ylvisaker]

helen said:

Whether there is a response mechanism between the center and peripheral after connecting, If so，Why does data loss occur?

Data can not be lost on a BLE link - if a packet is not acknowledged by the peer it will be resent. This happens both in the cases where the peer does not hear the packet, or in the case that the packet has been corrupted by noise and is thus discarded.
The SoftDevice handles this bit for you as well, so the application layer does not need to do anything in order to have packets retransmitted etc.

If you experience any dataloss in your application it likely happens on the application side before it is passed to the SoftDevice (such as if you have forgotten to check the returned error code from your SoftDevice write function call), or in the application layer on the peer's side.

Best regards,
Karl

[helen]

Hi

       When a central is connected with 10 peripherals,After a few minutes, one or two peripherals will be disconnected occasionally.Can the connection be stabilized through software configuration?

[Karl Ylvisaker]

Hello,

helen said:

Can the connection be stabilized through software configuration?

Could you elaborate what you mean when you say that you would like to stabilize the connection? The SoftDevice will handle all the scheduling of the different connections' timeslots, so you do not have to do any active scheduling here. When one or more of the connections are disconnected, their timeslot will be freed up and taken out of the SoftDevice's schedule automatically.

Best regards,
Karl