BLE Standard Service:

• Yes
• No

Proposed UUID(s) or link to specification document:

See specification and documentation on fota-service branch here:

https://github.com/ARMmbed/mbed-os-experimental-ble-services/tree/5328cacea69452901a691b7380366b6a188cf503/services/FOTA

@pan- @noonfom @paul-szczepanek-arm I took aspects from our discussion in #13 and wrote up a more formal specification README, taking the LinkLossService as an example.

The newly-renamed FOTAService strips out some complexity from my original DFUService proposal. I think the new specification covers the most basic use cases while providing for more advanced features and extensions in the future.

I have yet to refactor the code, but I'm planning to split off the BlockDevice dependency into standard FOTAService::EventHandlers that we provide. A user can implement their own custom logic if they wish, but we can provide a basic event handler for writing to a given block device. This also serves as a way for us to provide modular extensions (eg: delta updates, trigger connection parameter updates, etc) in the future as part of our standard library of event handlers.

Before I go much further on the code and tests, I wanted to get your feedback.

Let me know what you think and if I missed any corner cases.