Added Eddystone-URL support

[bneedhamia]

Added Eddystone-URL support: added setAdvertisedServiceData() to support BLE Service Data; changed Incomplete to Complete Service UUID list code in Advertising initialization, required by Eddystone-URL protocol; added (for debugging and testing Advertising) getAdvertisingLength() and getAdvertising() to enable a Sketch to view the generated BLE Advertising packet.

This change allows an Arduino 101 to be a beacon, specifically an Eddystone-URL beacon, as used in Google's Physical Web(tm) project. See https://google.github.io/physical-web/

[bneedhamia]

For an example sketch, see my Eddystone-URL Arduino 101 Sketch, which Advertises google.com via Eddystone/Physical-Web(tm) protocol . Should I add a version of this sketch as a CurieBLE example?

[bneedhamia]

I noticed I seem to have some typo in keywords.txt, because one of the new functions isn't highlighted in the IDE. Shall I correct that typo and push it to support-eddystone-url branch on my pull repo? ...or shall I wait for review to notice it.

[bigdinotech]

@bneedhamia sorry for the late review. Yes please go ahead and fix the typo. I will approve the pull request once that is done. Thanks.

[bneedhamia]

The keyword.txt corections are in.

[bigdinotech]

@calvinatintel please merge

[bneedhamia]

@Dan-Emutex @bigdinotech Excellent point. I'll take a look at @sandeepmistry Eddystone code and BLE library and if appropriate pull in the appropriate interfaces (in a new pull request). I wasn't aware of Sandeep's Eddystone code.

I had skimmed Sandeep's BLE library before I started, and at least in a quick skim of the code at that time, I didn't see Service Data support in the advertising - obviously from his Eddystone code, it must be hiding in there somewhere. I'll give his Eddystone code and BLE library a good read-over. I wouldn't want to diverge from his code.

Thanks again for the catch,
Brad

[sandeepmistry]

@bneedhamia service data is currently controlled by calling characteristic.broadcast(). There is also support to update the advertised value, via the setValue API if the characteristic is currently broadcasted.

This feature was left out of the CurieBLE library because controlling the advertisement data after begin() was not supported at the time to my knowledge. Maybe this has changed now?

@Dan-Emutex @bneedhamia thank you for bringing this discussion up. It would be great to continue to keep the CurieBLE API in sync with the BLEPeripheral library.

[Gerriko]

Any updates on this topic

[SidLeung]

@sandeepmistry , is service data broadcasting needed for the next BLE release? There was another discussion on similar topic here,

#420

[sandeepmistry]

@SidLeung, yes #420 would allow us to accomplish the same thing.

[ElliotMebane]

EddystoneURL sample with Curie 2.0.2:
https://github.com/ElliotMebane/Arduino/tree/master/EddystoneURL_Arduino101