Raspberry Pi Projects For Dummies. Evans Jonathan

You can use this option to make your Raspberry Pi go straight into the graphical operating system at startup. Otherwise, you have to start it manually (see the next section).

      ✔ Internationalization Options: This option takes you to a submenu where you can configure several options depending on where you’re located:

      • Change locale: Allows you to change your language and character set. Leave this option alone if you want to use your Raspberry Pi in English.

      • Change timezone: Tells your Raspberry Pi where you’re located. Afterward, it detects the time from your Internet connection.

      • Configure_keyboard: Allows you to select your keyboard model and layout. When you press Enter, a long list of keyboards will be displayed. If nothing seems to be happening, be patient. It can take a few seconds for the list of keyboards to show up. Choose the one you want to use and then select the keyboard layout you want to use (for example, UK).

      ✔ Enable Camera: If you’ve purchased an optional Camera Module, this menu allows you to set it up to work with your Raspberry Pi.

      ✔ Add to Rastrack: Racktrack allows you to add your Raspberry Pi to the global map of users around the world. You can see all the other tracked Raspberry Pis on their website at http://rastrack.co.uk.

      ✔ Overclock: Overclocking is a way of speeding up the CPU to perform calculations faster than the manufacturer intended. The clock speed is the heartbeat that determines how many instructions your CPU processes per second. Manufacturers build in a bit of leeway to ensure that they can guarantee the speed that your CPU is rated to. If you overclock your CPU, your Raspberry Pi will run faster, but its lifespan may be reduced, and it’s likely to run a bit hotter. If you change this setting and your Raspberry Pi no longer works, hold down the Shift key when you power up to return your Raspberry Pi to disable overclocking.

      ✔ Advanced Options: Advanced Options contains several settings that are a bit more involved, so we don’t use them in this book. But they are good to know. The options are as follows:

      • Overscan: Allows you to ensure that the picture is centered on your monitor and uses the available room correctly. If you have a black border around your image that you don’t want, disable this option. Otherwise, you can leave it alone.

      • Hostname: Allows you to set the name of your Raspberry Pi network. You probably won’t need to modify this.

      • Memory Split: Your onboard memory is shared between the CPU and the GPU. Depending on what you’re doing with your Raspberry Pi, your programs may use one or the other more intensively. For example graphics and gaming programs make more intensive demands on the GPU, so you can increase your Raspberry Pi’s performance by giving more memory to the GPU. Raspbian Wheezy uses 64MB to the GPU by default, and for most purposes this will be fine. You can experiment with this setting to see what setting works best for you.

      • SSH: Secure Shell (SSH) is a secure way of communicating between computers using an encrypted connection, so that you can control one computer from another one. Unless you’re familiar with this feature, you can ignore this option.

      • I2C: A communication protocol used by some external devices and sensors. This option allows you to enable or disable the I2C module so you can use these devices.

      • Serial: Allows you to enable or disable messages from the system on the serial interface. You most likely won’t need to change this unless you’re doing some kind of debugging.

      • Audio: Allows you to select whether audio is sent via the onboard 3.5mm audio jack or via the HDMI port. It’s set to auto by default, which means your audio will be routed via HDMI only when an HDMI screen is connected.

      • Update: From time to time, you may have to update Raspi-config. You’ll need an Internet connection to do this, but if you’re using a recently download distribution, you should be up to date.

      ✔ About raspi-config: This just describes what the Raspi-config tool does.

      When you’re finished making your selections, press the right arrow key twice to get to the Finish option and press Enter. You may have to reboot your Raspberry Pi, depending on the options you’ve selected.

      If you want to use Raspi-config later, you can start it by typing sudo raspi-config.

      Starting Up the Desktop Environment

      When you’ve finished configuring your Raspberry Pi with Raspi-config, you’re ready to start up. After you switch on your power, you may have to enter your username and password, depending on your settings. For Raspbian Wheezy, the username is pi and the password is raspberry. Make sure you type these in lowercase.

      After you log in, you’ll see the command prompt:

      pi@raspberrypi ~ $

      This means you’re up and running and you’ve logged into the operating system. Give yourself a cheer!

      It doesn’t like the graphical operating system you’re used to with a desktop computer, but the command line is the direct connection to your Raspberry Pi’s capabilities. You can execute all the main system commands and even do programming using only the command line interface. In a sense, the graphical environment is just a way of prettying up the command line and make it easier to use.

To get pretty, you launch the GUI, LXDE, by entering its startup command on the command line. To fire it up, type startx. It will take a moment or two to start up, and the screen will go blank for a bit. After startup, you should see the LXDE and a lovely red raspberry logo on the desktop wallpaper, as shown in Figure 1-6.

       Figure 1-6: Starting up the desktop environment.

      When you’ve got the desktop working, you can move on to learning about the programming tools in Chapter 3 or dive straight into the projects, if you’re familiar with programming.

       We recommend you peruse through Chapter 2 to make sure your workbench is set up for building the projects in this book. You’ll need a few tools to get going on many of them, and it’s a good idea to set up your workspace before you begin.

      Troubleshooting Your Raspberry Pi

      Things don’t always go according to plan. Here are some common problems and how you can try to solve them:

      ✔ No lights on your Raspberry Pi: This can happen if you forgot to connect the micro USB power connector or if the power supply isn’t capable of supplying your Raspberry Pi with enough power. Check that it’s rated to at least 5V 700mA (3.5 watts).

      ✔ Only the red light comes on: Your Raspberry Pi has power, but it can’t read the operating system on your SD card. First, make sure your SD card is firmly inserted. Then check that you’ve correctly created the disk image. If that doesn’t work, you can try testing your SD card on another Raspberry Pi to see if you get the same problem. If all else fails, try using a pre-imaged SD card.

      ✔ No output on the monitor: Check your monitor connection and your monitor’s power connection. Make sure that your monitor is turned on. (Sounds silly, but we’ve all done this at least once!) Then check that your monitor is using the correct input source. Use a button on the front of the monitor to cycle through them or use the monitor’s remote control.

      ✔ Inconsistent behavior or hang-ups: Your Raspberry Pi uses power at different amounts depending on what it’s doing. Make sure you have a good power supply and that it isn’t overtaxed.