Buttonless DFU problems when multiple connections present

Question

I'm using nRF52832 with SDK 15.0 and Softdevice S132. Within ble_dfu.c anytime a connection is established the on_connect function blindly sets m_dfu.conn_handle = p_ble_evt->evt.gap_evt.conn_handle. This creates problems if multiple connections are active (for instance a few central connections and one peripheral connection) since the last connection is always the one that the dfu routine conn_handle will end up pointing to (and this may a connection where the nRF is acting as the central) and on_rw_authorize_req checks this connection handle anytime a dfu command is received.

Hung Bui · Accepted Answer

Hi Daniel, 
 
 The ble_dfu.c was not designed with multiple connection in mind. It's more of an example for a very simple use case, 1to1 connection. 
 If you want to support multiple connection and allowing any connection to send the DFU command, I think you can remove the check in on_rw_authorize_req() 
 if (p_ble_evt->evt.gatts_evt.conn_handle != m_dfu.conn_handle) 
 And assign the m_dfu.conn_handle to the event connection handle if the authorizae write handle matched with the dfu control point handle.

Buttonless DFU problems when multiple connections present

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