Receiving connections from two central devices

[grzegorz]

Posted on September 07, 2017 at 16:37

My device works as peripheral in stack mode 2. This means it can handle connection from one central device only. I need to handle at least two central/master devices simultaneously. How can I do that? I suppose I need stack mode 3 or 4. What is the difference between them? There is nothing about this in PM0237. UM2058 says there can be 8 connections in Mode 3 and 4 connections in Mode 4, but there are no details whether it applies to central or peripheral role. I don't need central, I don't need scan. Just peripheral and advertising. I have found some slides which say there can be only 1 master connected in Mode 3 and two masters in Mode 4. Is that true? Does it mean that it's not possible to access BlueNRG-MS in peripheral role from e.g. phone, tablet, and computer at the same time? Where can I find official information about this?

#bluenrg-ms #stack-mode

[Antonio Vilei]

Posted on September 08, 2017 at 15:26

Firmware 7.2c of BlueNRG-MS handles the scenario that you need, i.e. a peripheral device connected to two different central nodes. For this use case please select Mode 4.

Simply start advertising and wait until you get the first connection from one central device (for example a phone). After the connection event, you can start advertising again. The BlueNRG-MS device will keep alive the first connection, while it will simultaneously send advertisements in order to be discovered by another central device (for example a tablet) and establish a second connection with it.

After the second central device will connect to your BlueNRG-MS, you can start advertising again, but this time you will be allowed to use non-connectable advertisement only, otherwise the advertising command will fail.