Navigation

Once you get to the Android landing page, you’ll notice that it looks similar to an Android tablet interface, complete with the message to “swipe up” to enter the homepage. If you’re using a screen with touch capabilities, you can plug the USB from your monitor into the Tinker Board and treat it like a tablet. If you prefer to use a keyboard and mouse, though, you can still do that.

Try to think of the mouse acting as a touch input. Every time you left-click, it’s like you’ve tapped the screen; and if you need to swipe in a certain direction, you’ll hold down the left button and move the mouse in the correct direction. You may experience some glitches using this method, though, as the mouse can become very sensitive compared to the inputs that the Android system is expecting from a touch input.

You can also use a remote, whether a traditional TV-style remote or gamepad, to navigate as well, like operating a Smart TV or other similar device. Since Android is set up to be a touchscreen operating system, a remote works very well for navigation. The remote can use a wireless dongle or Bluetooth (BLE) to communicate with the Tinker Board. These remotes are sold for home theater solutions or you can get adventurous and build your own using a development board that has BLE available onboard. We’ll be discussing remote control options with the Tinker Board during the project chapters as well, including how to build a quick and easy BLE DIY remote.

The Home Screen

Now that you’ve chosen how you’re going to navigate Android, let’s look at the default home screen provided by ASUS. As shown in Figure 6-1, in the top-right corner there is a battery status icon as well as a clock, like an Android phone display. Moving toward the middle of the screen there is an icon for the Contacts app and then right below that, from left to right, are the Email, Internet Browser, Apps Menu, Music App, Photos and Camera apps. We’ll explore the functionality of some of these apps shortly.

At the very bottom of the screen are navigation and utility controls. From left to right they are the Lower Volume, Back, Home, Overview, and Raise Volume buttons. For those unfamiliar with Android, the Back button will bring you back one page in an app, the Home button will usually bring you back to the home screen, and the Overview button will show you which apps are currently open. You can then quickly switch between apps or close apps out.

More Apps

There are more preinstalled applications in this Android distro than appear on the home page. If you go to the Apps Menu icon, it will open a new window which reveals all the apps that are currently installed, as shown in Figure 6-2. As you can see, the apps are standard Android and utility apps that you would expect to find after a fresh installation of an operating system. A lot of these apps will function best with an Internet connection available, so let’s connect to Wi-Fi and then come back to explore.

More Settings

While we’re in Settings, we might as well explore a bit. After finishing up with Wi-Fi, choose Back at the bottom of your screen to go back one page to the main Settings menu. Similar to other Android devices and iOS devices, it has settings options for Bluetooth, display, notifications, and so on. Some items here are a bit different, though, since they are set up for the Tinker Board and not for a mobile device. For example, as seen in Figure 6-3, there are additional Internet settings beyond Wi-Fi if you need them. Under the More button in Wireless & Networks there is a VPN option, which has become more common now for mainstream devices, but there are also Ethernet settings to check and configure as well.

Battery?

Moving down the Settings menu, you’ll see a Battery section. In that section, you’ll see an option to show the battery percentage. Any power source being used through the USB power port, whether it be a USB power supply or a portable battery bank, will show that the Tinker Board is “charging” and has a battery of 100% (Figure 6-5). Since this is an operating system for tablets and phones that have rechargeable batteries, and the Tinker Board does not have an onboard rechargeable battery, it will still show that the Tinker Board is “charging” and is at 100% when plugged into a wall outlet.

HDMI and Audio Source

One of the more important sections in Settings for the Tinker Board is the ability to select your audio and video inputs and outputs. If you navigate to the HDMI and Audio Source section, you’ll be able to choose your preferred options; such as audio traveling through HDMI or the headphone jack (Figure 6-6). Here you can also adjust the screen resolution, screen settings for zoom, and a timeout setting that sets a timer for when the screen will go to sleep, similar to energy settings on your laptop or desktop computer. All of these settings will be very important if you plan to use Android for media playback.

Turning on Developer Options

The last major setting that we’re going to walk through is turning on Developer Options. Finding it is a bit of an Android Easter egg, since it isn’t as simple as toggling something on or off. Scroll down to the very bottom of the settings page and click About Tablet. Once on that page, find the Build number section at the bottom of the screen. There you’ll see the current build number for the version of Android that you’re running on the Tinker Board. Now click the build number five times. A counter should pop up on the screen giving you a countdown to how many more clicks are required to enter developer mode. Once you’ve enabled it, it will say “You are now a developer!” on the screen, as shown in Figure 6-7.

Now go back to the main settings page and you’ll see a new option in System Settings, called Developer Options. Click it and you’ll see a lot of options that are a bit unusual to have access to. Most are for testing purposes for, you guessed it, Android developers. But a lot of them can be fun to play around with for more advanced users, such as enabling a Bluetooth snoop log, bug reports, and forcing GPU rendering to name a few. If you decide that you don’t want these settings enabled, you can toggle them off at the top of the page. Doing this doesn’t make the Developer Options entry in Settings disappear, though. After you enable it the first time, it will remain an option to toggle off and on in Settings going forward.

Camera

The Camera app allows you to take photos with a ribbon cable camera module or USB webcam. The camera module can be connected to the onboard MIPI CSI camera connector, which is located next to the HDMI port. The USB webcam would of course be plugged into one of the USB ports. We’re going to explore connecting a camera module to the MIPI connector for the purpose of walking through the app’s functionality.

There are many different cameras available that will be compatible with the MIPI connector from a variety of companies. You can go the route of a basic camera module or one with special features, such as a night vision camera or one that has interchangeable lenses. The classic ribbon cable cameras from the Raspberry Pi Foundation are also compatible, so if you have been doing Raspberry Pi projects and have a camera module then you can use that hardware with the Tinker Board.

To connect the camera, first locate the plug on the Tinker Board as shown in Figure 6-8, and gently lift-up the white plastic bar. This will eventually hold the ribbon cable in place.

Next, take your camera module and locate the exposed pins on the ribbon cable. The pins will be shiny in appearance and will need to make contact with the pins inside the plug on the board. Carefully insert the ribbon cable with the pins facing toward the HDMI port as shown in Figure 6-9. After you’re sure that the ribbon cable cannot be inserted any further, gently push down on the white lever on the plug to secure the camera’s cable in place.

After your camera is plugged into the socket, open the Camera app. You should see a message that the camera is being set up. After a few seconds it should recognize that the camera module is connected to your board and you should see what the camera is seeing displayed on screen as shown in Figure 6-10.

Camera App Functionality

The Camera app has basic functionality with a minimalist interface. You can take a picture by clicking on the camera icon located on the right side of the screen. You can also adjust flash, bring a grid overlay onto the viewfinder for optimally framed photos, and set a timer to delay by either 3 or 10 seconds when the picture will be taken after you press the button to take the picture. All of the photos that you take will be saved in the Gallery app, as shown in Figure 6-11. In addition to the preinstalled Camera app there are more apps you can use with a connected camera that provide additional functionality and features. We’ll look at an app that does this in a little bit.

The Music App

The preinstalled Music app is a robust player with a straightforward and well-organized GUI. There are tabs for Artists, Albums, Songs, Playlists and Now Playing. Clicking the option button (...) in the bottom-right corner brings up the options Party shuffle and Shuffle all. The difference between the two is that Party shuffle creates a playlist of songs of the same genre so that you can see what is going to be played next and add songs in or take songs out of rotation, whereas Shuffle all is completely random.

If you connect any external storage via USB that has audio files on it, the Music app will automatically find them and sort them according to the files’ metadata. As long as your metadata is correct, you will see all of your albums and artists as shown in Figure 6-12.

The Video App

The preinstalled Video app is a bit barebones. Available video files appear in a list, and selecting one allows it to play. As you saw with the Music app, if you connect a flash drive with videos on it, they will appear in the queue for playback. You can also review videos that you record with the Camera app, as shown in Figure 6-13. This app gets the basic job done; but if you’re looking for a GUI to similar the Music app’s and more options in general, consider the VLC Media Player for Android.

Using VLC

Like the default Music app, VLC can find video and audio files that are located on external storage devices. When you first attach a USB drive with VLC, you’ll be asked if you want to import the media stored on it, as shown in Figure 6-16. After a few moments, your videos and audio files will populate and be sorted according to their metadata.

All videos will play full screen; and if you’re using a mouse to navigate, mouse functionality will not be available during playback. This is an idiosyncrasy that pops up from time to time when using a keyboard and mouse with Android. You can pause and resume playback by hitting the space bar on your keyboard and exit playback to the main GUI by hitting Esc. After a video ends, you will be automatically brought back to the main GUI as well.

Audio files can be sorted by artist, album, songs, genre or playlists. If you play music in an album, the entire track listing will remain on the screen, and the song that is currently playing will appear at the bottom of the screen with pause and play buttons located in the bottom-right corner as shown in Figure 6-17. The track currently playing will also remain visible if you travel to other pages in VLC.

An additional feature is that music will continue to play in the background when using other apps, as with desktop music players. With the functionality available for both video and audio, VLC can be a single solution for media playback in Android on the Tinker Board, just like it was for TinkerOS.

Legal Considerations

The idea of installing apps without an app store sounds very freeing and makes Android feel more like a desktop operating system. But if this is making you wonder if there are any piracy or legal concerns associated with this process, then you’re absolutely right. If you were to download an app’s APK from a third-party website, especially an app that would cost money if you were to download it from an app store, and install that APK and run it, that would certainly be considered piracy and could be subject to legal action. In general, it’s ill-advised to download an APK file from a third-party site since there are virus concerns associated with many of them. So, with all of these red flag concerns in mind, why is this application included?

An ApkInstaller doesn’t have to be used for technological evil. If you were to develop your own Android app and install its APK, that would be completely legal, and you would have every right to do this. Other scenarios could be if another developer sent you their APK to install and test, or perhaps a company were to post an APK file online, like VLC, for their app to install outside an app store environment. All of these are perfectly legal and sensible uses of the ApkInstaller, and they are why ASUS includes it. This version of Android for the Tinker Board is really intended for developers to have a high-powered test bed to play around in Android so that they don’t have to have an emulator on their desktop or a phone or tablet.

How It Works

With all the disclaimers and background out of the way, we can go over how ApkInstaller works. First navigate to the ApkInstaller icon and launch it by clicking on it. The first time you open ApkInstaller, a message from Android lets you know that the app needs you to grant access to read from and write to external storage devices. This is so that external storage can be utilized by the app in case you are loading or saving APK files via USB storage devices. Allow the app to do this by clicking OK. Next, it will ask you to allow it to access photos, media and files on your device, an agreement similar to those often seen for Android apps. Select Allow to proceed. After the permissions have been set and the app opens, you’ll see that it’s a very simple GUI with buttons for Install, Manage, and Exit (Figure 6-18).

Install

If you have an APK file on your SD card, eMMC, or removable storage device that you want to install, use the Install button at the top. When you click Install, it brings you to a page that shows you the available storage devices connected to your Tinker Board, as shown in Figure 6-19. On the original Tinker Board, most apps, including ApkInstaller, consider the SD card to be the Internal Memory. It will almost never say SD card. Select your storage device and then navigate to the location of your APK file. Select the file and you’ll be prompted to proceed with the installation by clicking Install. After a few moments, you’ll receive confirmation that the file has finished installing with a pop-up window. You’ll also have the option to open the app right away from that pop-up.

Manage

The second option in ApkInstaller is Manage. By clicking the Manage button, you’re brought to a list of all the apps currently installed on your Tinker Board. If you click an app, you’ll be greeted by a menu with options to Launch, Export, Uninstall, or Cancel, as shown in Figure 6-20. Selecting Launch opens the app directly. Export exports the APK file for the app that you can then store for later installation. Uninstall uninstalls the app from your Tinker Board, and Cancel exits the Action menu. Another handy feature on the Manage page is the ability to see the version number for each app installed.

Exit

The last button available in ApkInstaller is Exit, and unlike its counterparts, it doesn’t have any advanced features of functionality; it simply closes out the app.

But as you can see, the ApkInstaller app is quite powerful and really opens up the Android experience for developers. It does some things with a single click that can sometimes be nearly impossible or extremely difficult otherwise. But as discussed earlier, it’s important to use this app for its intended purpose only and not to use it for malicious purposes.

Installing F-Droid

The installation process for F-Droid is a lot like what we did for VLC media player. First, we’re going to navigate to F-Droid’s web site.² Toward the middle of the F-Droid homepage (Figure 6-22), there is a Download F-Droid button. Clicking here will begin to download the APK file to your Tinker Board. After the download completes, a notification will appear at the top of your screen and prompt you to install the APK file. Click Install and after a minute or two the installation will finish, and a pop-up window will let you know that F-Droid has finished installing. From there you can click to open F-Droid.

Exploring F-Droid

After opening F-Droid, you’ll notice that the layout is very similar to other app stores with a landing page showcasing featured apps of different genres, as shown in Figure 6-23. The focus of F-Droid is to offer open source apps that appeal to the open source community, so there are many developer tools available here as well as apps featuring Tux as their icon mascot.

Almost every app genre is featured here, though, from audio players to Internet security to games. We’re going to look at a couple of apps from F-Droid to fill in some gaps left by the absence of the Google Play store that some avid Android fans may be feeling.

Installing an app from F-Droid is very simple. Navigate to an app that you wish to install, and you’ll see a button for Install (Figure 6-24). Click that, and the download process will begin. After the app has downloaded, you’ll be asked if you want to install the app. Agree to the installation by clicking Install, and after a few seconds your app will be ready to use. A pop-up will ask if you’d like to launch the app. You can click Launch to go directly into the app or Cancel to continue browsing F-Droid.

As you can see, there are a wide variety of apps to choose from and try out in the F-Droid store. A few that many people may find particularly interesting are Newpipe, 2048, and Open Camera.

The Newpipe app is a YouTube player that pulls from YouTube in close to real time by showing you trending videos and having a search option that seems to be on par with what you would expect from the desktop site or an official app. You can also view videos in their full resolution and adjust video settings as needed as shown in Figure 6-25. Of course, you can view YouTube videos in the included Internet browser, but having a standalone app option can sometimes offer a better experience, especially on a mobile OS such as Android.

It really wouldn’t be a mobile OS experience without games. 2048 is a game that has been very popular on smart phones, and it has an open source port to F-Droid (Figure 6-26). It’s a numbers-based game and although you can play it with a mouse, serious players may want to hook up a touch screen for the full experience.

Media playback and games are great, but let’s wrap this up with a look at a more functional app: Open Camera. Open Camera is a camera app that utilizes a camera attached to the Tinker Board just like the included Camera app in the Android distro. Open Camera is a much more robust camera app though, featuring many advanced controls, such as zoom, bitrate, and framerate controls for video and a customizable GUI.

Using Open Camera for Time-Lapses

One feature that really stands out for Open Camera is the timer. This allows you to set up a time-lapse camera with very little effort. Time-lapse camera projects with single-board computers are quite popular because of their size, processing power, and storage capabilities. Often this is done in a Linux operating system, like TinkerOS, but that requires programming and can be complicated depending on your needs. Using Open Camera with this Android distro, though, makes things simple and allows you to adjust settings easily if you need to through the GUI.

To access the timer settings, click the Settings icon in the top-right corner of the app, which resembles a machine cog, as shown in Figure 6-27. After getting to the Settings page, you’ll find the timer settings conveniently located at the top under Camera Controls.

To set up a continuous time-lapse we’ll first need to select how often we want a picture to be taken. Click the Timer option at the top of the page, which will have a menu with different time intervals, as shown in Figure 6-28. Select the option that makes the most sense for your time-lapse subject. Longer intervals are great for longer time-lapses, such as sunsets. Shorter intervals are ideal for things like project builds or 3D prints. After you’ve made your selection, this menu will minimize.

Next, select how long your time-lapse will last by clicking the Repeat option. You’ll see that there aren’t as many options here, as shown in Figure 6-29. If you want to capture a quick time-lapse, then any of the 2X to 10X options will work well for you, but for anything longer than ten photos you’ll want to select Unlimited. This means that the time-lapse will continue running until you stop it manually.

The final step is to go to the Repeat mode interval option, as shown in Figure 6-30. You’ll want this setting to match your Timer setting. For example, if you’ve selected 5 seconds for your Timer, then you’ll choose 5 seconds for your Repeat mode interval. Otherwise, you may find that you’re taking too many or too few photos in most cases. However, feel free to experiment for different effects and results.

After your settings are set up, return to the main Open Camera GUI, where you’ll see your camera preview screen. To begin your time-lapse, you’ll click the camera icon on the right side of the screen. Your time-lapse will begin and you’ll see a countdown that matches your Timer interval that was set up in the previous steps, as shown in Figure 6-31. Now your time-lapse is running until you end it by clicking the camera icon again. After you end it, a small message will appear briefly on the screen that says “Cancelled timer.” As you can see, this makes time lapses very simple to set up and configure to your needs. There are many more features within Open Camera, too many to go over in this chapter, but hopefully you now have an idea of what it has to offer when used on the Tinker Board and the possibilities of many of the apps available from F-Droid.