Geolocation in iOS

Chapter 1. Introduction

The arrival of the iPhone changed the whole direction of software development for mobile platforms, and has had a profound impact on the hardware design of the smartphones that have followed it. The arrival of the iPad has turned what was a single class of devices into a platform.

That platform is one of the most popular for geolocation: it’s used for everything from driving directions to finding a restaurant. As a developer, you can get in on the geolocation game by using the Core Location framework, one of the most powerful and interesting frameworks in the iOS SDK. It abstracts the details of determining a user’s location, and does all the heavy lifting for you behind the scenes.

Hardware Support

Unique amongst modern mobile platforms, Apple has gone to great lengths to ensure that your code will run on all of the current iOS-based devices. Yet despite this, there is still some variation in hardware between the various models (see Table 1-1).

Table 1-1. Hardware support in various iPhone, iPod touch, and iPad models

Hardware features	iPhone					iPod touch				iPad		iPad 2		New iPad
	Original	3G	3GS	4	4s	1st gen	2nd gen	3rd gen	4th gen	WiFi	3G	WiFi	3G	WiFi	3G
Cellular	✓	✓	✓	✓	✓	✗	✗	✗	✗	✗	✓	✓	✓	✓	✓
WiFi	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Bluetooth	✓	✓	✓	✓	✓	✗	✓	✓	✓	✓	✓	✓	✓	✓	✓
Speaker	✓	✓	✓	✓	✓	✗	✓	✓	✓	✓	✓	✓	✓	✓	✓
Audio In	✓	✓	✓	✓	✓	✗	✓	✓	✓	✓	✓	✓	✓	✓	✓
Accelerometer	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Magnetometer	✗	✗	✓	✓	✓	✗	✗	✗	✗	✓	✓	✓	✓	✓	✓
Gyroscope	✗	✗	✗	✓	✓	✗	✗	✗	✓	✗	✗	✓	✓	✓	✓
GPS	✗	✓	✓	✓	✓	✗	✗	✗	✗	✗	✓	✗	✓	✗	✓
Proximity Sensor	✓	✓	✓	✓	✓	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗
Camera	✓	✓	✓	✓	✓	✗	✗	✗	✓	✗	✗	✓	✓	✓	✓
Video	✗	✗	✓	✓	✓	✗	✗	✗	✓	✗	✗	✓	✓	✓	✓
Vibration	✓	✓	✓	✓	✓	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗
Retina Display	✗	✗	✗	✓	✓	✗	✗	✗	✓	✗	✗	✗	✗	✓	✓

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