Slides from the Birmingham Xamarin user group meeting: A little less conversation, a little more iBeacons… iBeacons are a cool technology that allows you to add location awareness to you apps, not based on your location on a map, but based on your proximity to iBeacons, be they at a fixed or moving point. They allow your apps to have an accurate understanding of where you are both inside and out, from sending you offers when you are in a shop to knowing where you are in a sports stadium so you can be directed to your seat. iBeacons are a big up and coming thing - even Facebook are now sending them out to businesses so their app can become location aware. Companies like Estimote are creating and extending iBeacons to bring even more amazing features to the developer. In this mini-hack I’ll be talking briefly about this technology and a little about it’s uses, then we’ll hit the code. Bring a Mac laptop, iPhone and lightning cable, and team up with others in building a treasure hunt app using the Estimote iOS Xamarin component and Estimote iBeacons. There will be a prize of an Estimote developer kit or two (containing 3 iBeacons, worth $100 each) for the team that can complete the treasure hunt the fastest.

1. A little less conversation,
a little more iBeacons
Estimote iBeacons mini-hack
Jim Bennett
@JimBobBennett
http://JimBobBennett.io

2. What are we going to do
tonight?
• A quick overview of iBeacons
• The cool things you can do with them
• Hands on with the Estimote Xamarin component
• Lets play! Team up and build a treasure hunt app,
and win some beacons

3. What are iBeacons?
• Bluetooth LE devices
• Broadcast a fixed format
message defined by Apple on a
periodic basis
• Message has an Id, version
(major, minor), measured power
• Multiple iBeacons can have the
same Id, versions can be use to
distinguish different iBeacons

4. How do they interact with
your app?
• Apple defines an API to interact
with iBeacons as part of
CoreLocation
• Apps can register to monitor a
region - all beacons with a given Id
• Monitoring notifies when an
iBeacon moves in or out of range
• Monitoring can happen in the
background and will launch your
app
• Once your app is in the foreground,
you can range the iBeacons to get
their proximity/distance as it
changes

5. What does this mean for
your app?
• Indoor location awareness
• Context awareness

6. What apps can you build to
take advantage of this?
• Museum guide - app knows which exhibit you are
standing next to and plays the correct audio
• Theatre location - app can pinpoint your location and
direct you to your seat
• Shopping - notifications of special offers when you are
next to the items on offer
• Respond to indoor location - turn your lights off when
you put your phone down on your bedside table, notify
friends when you are home safe

7. Problems!
• Security - anyone can read your beacon by scanning
for Bluetooth devices and spoof your id
• Power - some iBeacons run off the mains so need
socket, battery powered ones will die and need
replacing
• Accuracy - not very, for example in a busy location
people can decrease signal strength
• No simulator support - need an actual device for
debugging

8. Estimote iBeacons
• Estimote have extended the
capabilities of their iBeacons
• Distance measurements, flip to
power off
• Indoor location SDK
• Android support
• Xamarin component
• Nearables
• Strong developer community support
• Other iBeacon providers are
available

9. Best of all!
Free beacons!
2 dev kits to be given away, everyone gets 10% off their first Estimote
order and Stickers for everyone

10. Code
Examples at:
https://github.com/jimbobbennett/iBeaconsMiniHack
https://gist.github.com/jimbobbennett

11. Step 1 - add the component
• Install the Estimote SDK for iOS component

12. Step 2 - add the permissions
• Need either NSLocationWhenInUseUsageDescription or
NSLocationAlwaysUsageDescription set

13. Step 3 - Setup the
BeaconManager and
authorise
• Create a BeaconManager - this wraps CLLocationManager
• Listen for changes to the authorisation status
• Request permission

14. Step 4 - Start ranging
beacons
• To range you need to specify a region
• Each region is based on a UUID and optionally a major and minor
version
• Each region must have a name and you can use this in the event
handler to correctly handle the ranging of beacons from multiple
regions
• By default all brand new Estimote iBeacons have a UUID of
B9407F30-F5F8-466E-AFF9-25556B57FE6D

15. Step 5 - Handle the ranged
beacons
• The Ranged event provides a list of beacons
• Contains just the one that was ranged, or all of them depending on the
setup

16. Gotcha’s
• Distance of -1
• Means not enough signal or advertising packets - ramp up the
broadcast rate
• Checking for equality
• Beacons are equal if the UUID/version matches. Beacons in the event
args are new instances.
• Not working - check authorization!
• Make sure your code requests authorization and handles the denied
case.

17. Lets find some treasure!
Your challenge:
Form small teams - ideally 3 to a team
There will be 3 beacons hidden in another room
Write an app to find the beacons and record the
letters written on each
Each team will enter the room one at a time - the
fastest team to locate them all wins some booty - an
Estimote iBeacons dev kit with 3 iBeacons - worth
$100
Afterwards each team will show off their results. The
team with the best app wins another Estimote dev kit

18. Useful links
• http://estimote.com
• https://gist.github.com/jimbobbennett/07fb701789abce7bdc8b
• https://github.com/jimbobbennett/iBeaconsMiniHack
• https://developer.apple.com/library/ios/documentation/UserExperience/
Conceptual/LocationAwarenessPG/RegionMonitoring/RegionMonitoring
.html#//apple_ref/doc/uid/TP40009497-CH9-SW1
• http://motzcod.es/post/105283789517/ios-ibeacon-background-region-
monitoring
• http://motzcod.es/post/97662738237/scanning-for-ibeacons-in-ios-8
• https://www.brooklynmuseum.org/community/blogosphere/2015/02/04/t
he-realities-of-installing-ibeacon-to-scale/