Basic Sensors in iOS

Chapter 1. The Hardware

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 smart phones that have followed it. The arrival of the iPad has turned what was a single class of device into a platform.

Available Sensor Hardware

While the iPhone is almost unique amongst mobile platforms in guaranteeing that your application will run on all of the current devices (see Figure 1-1), however there is an increasing amount of variation in available hardware between the various models, as shown in Table 1-1.

Figure 1-1. Timeline showing the availability of iPhone, iPod Touch, iPad models

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

Hardware Feature	iPhone				iPod touch				iPad		iPad 2
	Original	3G	3GS	4	1st Gen	2nd Gen	3rd Gen	4th Gen	WiFi	3G	WiFi	3G
Cellular	☑	☑	☑	☑	☐	☐	☐	☐	☐	☑	☐	☑
WiFi	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑
Bluetooth	☑	☑	☑	☑	☐	☑	☑	☑	☑	☑	☑	☑
Speaker	☑	☑	☑	☑	☐	☑	☑	☑	☑	☑	☑	☑
Audio In	☑	☑	☑	☑	☐	☑	☑	☑	☑	☑	☑	☑
Accelerometer	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑	☑
Magnetometer	☐	☐	☑	☑	☐	☐	☐	☐	☑	☑	☑	☑
Gyroscope	☐	☐	☐	☑	☐	☐	☐	☑	☐	☐	☑	☑
GPS	☐	☑	☑	☑	☐	☐	☐	☐	☐	☑	☐	☑
Proximity Sensor	☑	☑	☑	☑	☐	☐	☐	☐	☐	☐	☐	☐
Camera	☑	☑	☑	☑	☐	☐	☐	☑	☐	☐	☑	☑
Video	☐	☐	☑	☑	☐	☐	☐	☑	☐	☐	☑	☑
Vibration	☑	☑	☑	☑	☐	☐	☐	☐	☐	☐	☐	☐

Most of the examples in this book will be built as iPhone however depending on the availability of hardware the examples will run equally well on the iPod touch and iPad; the underlying code is equally applicable as we’re dealing for the most part directly with that hardware.