Notify to all connections

[T.N.]

Hi.

I'm testing multiperipheral function, and have established multiple connections (1 single Peripheral with multiple Centrals). But it seems that the Peripheral can just notify values to the last connected Central.

Could you tell me how to notify values from 1 single Peripheral to all Centrals?

[shibshab]

1 single Peripheral can only be connected to one Central at a time.

To issue a notification to any connection in a multi Peripheral setup, you pass the appropriate connection handle to uint32_t sd_ble_gatts_hvx ( uint16_t conn_handle, ble_gatts_hvx_params_t const * p_hvx_params ) .

[endnode]

Hi both,

First of all GATT Notifications don't relate to GAP roles at all, these are independent (in other words you can have GAP Peripheral and on top of that GATT Client or GATT Server or even both). Secondly since BT4.2 you can have multiple GAP Peripheral roles/links active on single controller and that's the case of latest S132/S112/S140 Nordic stacks on nRF52 chips. However each connection is treated separately including all upper layers such as GATT Server.

Nordic interpret BT4.2 specification in the way that there can be only one GATT Server instance at the time (search for answers on this forum, here is one example) however state of particular GATT objects such as CCCD or exercising (G)ATT methods such as Notification are per link. So in case you want to Notify multiple GATT Clients you need to issue multiple Notifications by calling sd_ble_gatts_hvx as per shishab's suggestion.

[T.N.]

Thank you for all. I've tested it and it works fine.

[Kyle Krueger]

Hi Nack, if shibshab's answer worked for you, could you please mark it as correct?

[Petter Myhre]

As endnode pointed out, in later SoftDevices a peripheral can be connected to several central concurrently.