Buttonless DFU Example SDK15 - No DFU Service

[David Challender]

Hi,

I have completed all steps in the example at the following link https://devzone.nordicsemi.com/b/blog/posts/getting-started-with-nordics-secure-dfu-bootloader and all works OK.

Without modification i have compiled the Buttonles DFU application example, created a zip file and sucessfully loaded it onto the device. However the only service is a LED Button Service and was expecting A DFU service.  Can action DFU by pressing Button 4 and Reset but need a buttonless service.  Does the example application code require further configuration to operate? 

[Vidar Berg]

Hi,

I'm guessing your device had the LED Button service previously and  the central has cached this, hence skipping service discovery on re-connect. Central is allowed to do that if the service changed characteristic is not included (enabled/disabled with NRF_SDH_BLE_SERVICE_CHANGED define in sdk_config.h). On iphone you can clear the cache by toggling flight mode enable. 

It is recommended to use the service changed characteristic if the device supports DFU since the attribute handles may change. More information about the service changed characteristic can be found in core spec. 5, Part G, section 2.5.2.