book

Raspberry Pi Hacks

by Ruth Suehle, Tom Callaway

December 2013

Intermediate to advanced

394 pages

9h 43m

English

O'Reilly Media, Inc.

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Who This Book Is ForHow to Use This BookHardware RequirementsConventions Used in This BookUsing Code ExamplesSafari® Books OnlineHow to Contact UsAcknowledgmentsContributors
Hack 1. Choose and Format the Right SD CardHack 2. Mount the SD CardHack 3. Decode the LEDsHack 4. Update the FirmwareHack 5. Monitor the Raspberry Pi HardwareMeasure Component VoltageMeasure TemperatureMonitor Memory SplitCheck Custom Configuration OverridesHack 6. Overclock Your PiIncrease ARM CPU FrequencyIncrease SDRAM FrequencyIncrease GPU FrequencyPretested Overclock PresetsHack 7. Overvolt for Higher PerformanceHack 8. Get More USB PortsHack 9. Troubleshoot Power ProblemsThink Twice Before Using the GPIO to Power the PiDo Not Backpower the Pi over USBGet Power Through GPIO SafelySolve Power ProblemsGet a better power supplyGet a better micro USB cableTest Your Cable’s ResistanceHack 10. Unbreak Your Raspberry PiTest Your Power SupplyReplace the C6 CapacitorHack 11. Go HeadlessHack 12. Connect with SSHHack 13. Give Your Pi a Static IP AddressHack 14. Learn to Speak GPIOPin-Number LabelingBCM LabelingLabel Your Own GPIO PinsHack 15. Connect GPIO Pins to a BreadboardGPIO Quick ReferenceInter-Integrated Circuit (I2C)Pulse-Width Modulation (PWM)Universal Asynchronous Receiver/Transmitter (UART)Serial Peripheral Interface Bus (SPI)Hack 16. Add a USB Serial ConsoleMinicomScreenUsing the Serial Device as a Login ConsoleWeird Noise (or Missing Signal) on the Serial Connection?Hack 17. Add a Reset ButtonHack 18. Get Power to the Pi on the MoveHack 19. Test Your Might (in Volts)Hack 20. Add Additional Memory with Swap
Hack 21. Build a Cross-Compiler ToolchainInstall crosstool-ngConfigure crosstool-ngAdd crosstool-ng to Your PATHConfigure the Cross-CompilerPaths and Misc OptionsTarget OptionsToolchain OptionsOperating System OptionsBinary Utilities OptionsC Compiler OptionsC-library OptionsBegin the BuildHack 22. Build a Custom KernelDownload the Kernel Source TreeConfigure the Linux KernelBuild the Kernel ImageInstall a New KernelPost-Installation TasksHack 23. Update to the Latest Prebuilt KernelGet the Prebuilt Linux KernelInstall the Prebuilt Kernel ModulesHack 24. Split Memory Between the GPU and Linux UserspaceAllocate Memory with config.txtAutomatically Share MemoryHack 25. Update the Firmware and Prebuilt Binary Kernel the Easy WayHack 26. Emulate the PiHack 27. Try Occidentalis: The Raspberry Pi Distro for (Advanced) EducationHack 28. Monitor the Pi’s IP AddressBuild the LCD Pi PlateInstall Software to Control the LCD Pi PlateRun the CodeHack 29. Run Android on the Raspberry Pi
Hack 30. Share Files with SambaHack 31. Use Your Raspberry Pi as a Remote Print ServerHack 32. Make Calls with a Raspberry Pi Asterisk Telephone SystemInstalling AsteriskStarting AsteriskSetting Up a SoftphoneConfigure an SIP accountRegister your SIP clientSet up an extension in the dialplanHack 33. Build Your Own Web ServerSet Up a Basic Blog ServerUse Coder for Your WebsiteHack 34. Control a LEGO RobotInstalling ROS and DependenciesTesting the ROS Connection to the NXT BrickJust Python, PleaseHack 35. (Appear to) Survive a Gaping Chest WoundBuild the CostumeAdd the Battle WoundA Simple ScriptFinish the CostumePut It All TogetherHack 36. Look for AliensSetting Up BOINCBOINC Account ManagersBOINC Account Manager (BAM!)GridRepublicAndroBOINC
Hack 37. Tell the Temperature Outside (Without Going Out There)Hack 38. Check on Your PlantsHack 39. Make Your Pi Water-Resistant (with a Case)Hack 40. Make Your Pi Water-Resistant (Without a Case)Hack 41. Find Geocaches from Your CarGathering HardwareGPS receiverLCD screenPower cordSerial consoleIndicator LEDProject boxPreparing the Software ImageWiring the Cacheberry PiLoading Cache DataHack 42. See the LightAccessing the Sensor via PythonAccessing the Sensor Directly from the KernelHack 43. Listen to Aircraft TranspondersSet Up the CodeRun the ScriptHack 44. Control Aerial PhotographyBuild the PayloadGather Gas, Balloon, and ParachuteInstall SoftwareTrack the PayloadPrepare for LaunchMission SuccessHack 45. Have the Best Holiday Lights DisplayConnect the HardwareInstall the Software
Hack 46. Play Video FilesHack 47. Enable Additional Video CodecsHack 48. Build a Pi MusicBoxGetting and Configuring the SoftwarePlaying MusicMulti-room audioMusic Player Daemon (MPD)Networked musicLocal musicSound ConfigurationSecurityGetting Your Hands DirtyMopidyrc.localWorking at MidnightStatic networkUpdatingHack 49. Turn Your Pi into a RadioHow It WorksAccessing HardwareFun with FMHack 50. Control the Pi via TouchscreenChoosing a TouchscreenInstalling and Enabling DriversXorg ConfigurationUsing the TouchscreenHack 51. Emulate Classic Video Game ConsolesHack 52. Connect a DSLRGeting Started with gPhotoBasic Capture Commands and VariablesFinding More About Your CameraHack 53. Set Up a PhotoboothHack 54. Turn Your Pi into a Tiny Media CenterDecode MPEG-2 and VC-1Add a Remote ControlShortcut for Cord CuttersAdd Some ContentHack 55. Watch Movies in the Backseat of Your CarYour Reliant (in Terms of Power) AutomobileStorage for Your MoviesTouchscreenPowered USB HubSoftwareEnabling Touchscreen SupportAdding VideosPutting It All Together
Hack 56. Control GPIO from a Web BrowserHack 57. Add a Tiny ScreenHack 58. Connect Arduino Shields to Your Raspberry PiUsing the arduPi LibraryEnable the UART portCompile the arduPi library and a program using itRun your programGPIO inputAnalog-to-Digital ConversionUARTI2CSPIHack 59. Control a 3D PrinterHack 60. Add a Numeric KeypadHow the Matrix Keypad WorksConnecting the Keypad to the Raspberry PiInstalling the SoftwareRunning the ProgramHack 61. Add a Heat SinkHack 62. Enable the Raspberry Pi Camera on PidoraHack 63. Build a Solar-Powered LabGather HardwareSet Up the Raspberry PiHack 64. Build a MIDI Controller (on the Cheap!)HardwareSoftwareErgonomicsHack 65. Build a Raspberry Pi SupercomputerBuild MPI to Run Code on Multiple NodesFlash Me… OnceUse SSH Instead of Password Login Between the PisBuild More NodesUse Python Bindings for MPINotes on Making MPI Shared Libraries for Raspberry Pi

Content preview from Raspberry Pi Hacks

Chapter 2. Hacking Linux for the Raspberry Pi

While there are many available operating systems for the Raspberry Pi, the most supported one is Linux. The Raspberry Pi Foundation maintains a Linux kernel source tree with support for the Raspberry Pi hardware.

Linux is famous for its flexibility and support for a large number of devices. Whether you are just interested in learning Linux, or if you need to make some modifications in order to enable an awesome hack, this chapter will help you through the process.

Hack 21. Build a Cross-Compiler Toolchain

The Raspberry Pi is well-suited for many things, but compile speed is not one of them. To build anything of consequence from source in a reasonable amount of time, you’ll need to to use a cross-compiler running on a faster computer.

A cross-compiler is a compiler (and dependent libraries) built to run on one architecture but that generates binaries for a different architecture, usually an incompatible one. In this case, you need a cross-compiler that will allow you to build binaries optimized for the Raspberry Pi Linux environment.

Like most tasks in Linux, you can generate a cross-compiler in a few ways, but to ensure that you end up with a toolchain optimized for the best performance on the Raspberry Pi, we suggest not installing prepackaged cross-compilers that come with your Linux distribution. Instead, the following sections will walk you through the process of using crosstool-ng to build it from scratch.