I've been able to port the DFU process into a C# app running within a Linux gateway.
I'm using the buttonless without Bonds service to enter DFU mode.
The problem I have is that on many occasions after I have sent the command to enter DFU mode I'm not seeing the bootloader advertise so are unable to access its services and characteristics.
Within the bootloader I can see from our LED indicators that the NRF_DFU_EVT_TRANSPORT_ACTIVATED event has been raised, but using the nRF Connect app on my phone I can confirm there are no adverts from the bootloader DFU so it is not just my gateway that is not picking them up.
My gateway only attempts to upgrade one device at a time and is not performing any other connections / snooping at the time the enter DFU command is sent.
This is not specifically limited to a particular device, I have 10 set up and on my last test 6 upgraded (some required 2 or more attempts to get the adverts to start) and 4 did not connect.
Running the test again can change which devices respond and which do not.
I've never seen this when using the nRF toolbox app so suspect it may be how I'm handling the disconnect after sending the DFU command, but it works more often than not so must be very specific.
Can anyone suggest anything that may explain this behaviour or something I could try to increase the chances of the bootloader starting to advertise its DFU availability?
Thanks for any assistance you can provide
