Would like to understand maximum concurrent connections for nRF52832 or nRF52840

[thin_ice]

Hello, 

From the documentation I read that Softdevice can support maximum 20 BLE concurrent connections. How does Nordic determine this maximum number of 20 and is this arbitrary number hard coded in software or from other limitations ? What would it be for "serialized connectivity" application ?

If Zephr is used for BLE stack, can nRF device have 20+ connections and do you think they are better than Softdevice ?

Thank you !

[AndreasF]

Hi.

During the minimum connection interval, which is 7.5 ms, it is only possible to preprocess, transmit (251-byte packet), and postprocess,  20 times in that connection interval. It is a limitation set by the requirement of pre- and postprocessing time of every packet.

 

If Zephr is used for BLE stack, can nRF device have 20+ connections and do you think they are better than Softdevice ?

 You really have the same issue as with the SoftDevice, it depends on what you wish to do, how much information is transmitted.

Best regards,

Andreas

[Martin H.]

Hi AndreasF,

I have a follow-up question regarding max-concurrent-connections:

Is it possible to have 20 central-connections + 1 peripheral-connection ?

The following settings dosen`t result in error:

NRF_SDH_BLE_TOTAL_LINK_COUNT            21

NRF_SDH_BLE_CENTRAL_LINK_COUNT       20

NRF_SDH_BLE_PERIPHERAL_LINK_COUNT 0