nRF52840 Max number of connected devices

[MikePK]

Hi,

We need to design a network with one master and 36 devices connected, with "long range" capability, exchanging sometime messages from 100 to 4000 bytes.

The number of communications/minute is not big, but when it's necessary to cummunicate, it must be done quickly, so the devices must be permanentely paired (connected) with the master.

The software limit with the 52840 stack seems to be at 20 devices maximum, but it is only due to the stack software, that's correct ?

Is there any hardware or protocol reason to limit at 20 ?

If no hardware or protocol limitation, how may we push this limit at 36 devices ?

Kind regards,

Mike

[bjorn-spockeli]

Hi Mike,

Yes, the S140 v6.1.0 SoftDevice(i.e. BLE protocol stack) supports up-to 20 concurrent connections and this is a hard limit for our protocol stack.

If you need 30 concurrent connections then I suggest that you take a look at Mynewt's Nimble stack. It supports up-to 32 concurrent connections and it supports the nRF52840. 

Best regards

Bjørn