Hardware Tools for Android App Development
Google gives developers the tools to create first-class, full-featured mobile apps. Google makes it easy to access and make use of all the devices on the device.
To create an amazing Android app, you must take advantage of all that the hardware has to offer. Don’t get us wrong – if you have an idea for an app that doesn’t need hardware assistance, that’s okay too.
Android devices come with many hardware features that you can use to create apps. The table describes the hardware features that are available on most Android devices.
Android device Hardware
Android devices feature What it does
The accelerometer indicates whether the phone is moving or not
Bluetooth radio indicates whether the headset is connected or not
The compass indicates the direction the user is heading
Camera Take pictures and record video
The GPS receiver indicates the user’s location
Most Android devices are released with the devices discussed in the next four sections, but not all devices are created equal. Android is free to be distributed by device manufacturers, so it is used in a wide variety of devices, including some made by small manufacturers overseas (and it’s not uncommon for some of these devices to miss a feature or two).
Android devices come in all shapes and sizes: phones, tablets, e-book readers, watches, televisions, and cars. The engineers behind Android provide tools that allow you to easily deploy apps on multiple screen sizes and resolutions. Don’t worry – the Android team has done all the hard work for you.
Touch screen
Android touch screen opens up a lot of possibilities to improve users’ interaction with your apps. Users can swipe, swipe, swipe or pinch to zoom, for example, by sliding a finger on the touch screen. You can also provide custom gestures in your app, which opens up more possibilities.
Android also supports multi-touch capability, which allows the user to touch the entire screen with more than one finger at a time.
Hardware buttons are old news. You can place buttons in any shape anywhere on the screen to create the most appropriate user interface for your application.
GPS
The combination of the Android operating system and the GPS receiver on the device allows the developer to access and track the user’s location at any time. The social networking app Foursquare is a good example – it uses GPS to locate the user and then accesses the web to locate the user’s closest places.
Another useful example is the ability of the Maps app to locate a user on a map and provide directions to that person’s destination. The combination of Android and GPS devices allows you to access the exact GPS location of the user. Many apps use this combination to tell users where the nearest gas station, coffee shop, or even a restroom is.
Accelerometer
Accelerometer is a device that measures acceleration, Android comes with accelerometer support. The accelerometer tells you if the user’s device is moving or vibrating, and even in which direction it is being rotated. You can then use this information as a way to control your app.
You can use the accelerometer to perform simple tasks, such as determining when to turn the device upside down and then completing an action. For example, you can immerse users in the gameplay by having them shake their devices to roll the dice. This level of benefit is putting mobile devices apart from typical desktop PCs.
Hint
“Android has built-in activity recognition, which uses various sensors such as the accelerometer and GPS to determine if the user is currently walking, running, driving or cycling.”
SD card
Android gives you the tools you need to access (save and load) files on the device’s SD card — a portable storage medium that you can insert into compatible phones, tablets, and computers. To avoid bloating your app with extra required resources and hogging limited built-in memory, you can download some or all of your application’s resources from your web host and save them to the device’s SD card (which makes users less likely to uninstall your app when they need to clear space on their devices).
Not every device has an SD card preinstalled, though most do. Always ensure that a device has an SD card installed and that adequate space is available before trying to save files to it. Also, be aware that any file you place on an SD card is not secure, and can be read by other apps on the user’s phone.