Rui Santos

Cheat Sheet / Updated 04-14-2022

BeagleBone is an exciting tiny board that brings your electronics and software projects to life. Its affordability and ease of use make it popular among hardware enthusiasts and programmers. The following articles help you get started using this powerful board.

Step by Step / Updated 03-27-2016

Capes are plug-in boards that you can plug on top of the BeagleBone computer to add extended capabilities to it in a simple manner. Capes give you quick access to some easy-to-use systems such as LCD screens, GPS modules, and motor controllers. Some of these are introduced here; if you’re interested in checking out the enormous list of capes, visit BeagleBoard: BeagleBone Capes. Some capes aren’t compatible with both the Original BeagleBone and the BeagleBone Black. Always check ahead or ask the manufacturer before making a purchase.

Step by Step / Updated 03-27-2016

The BeagleBone is an outstanding tool for so many programs because . . . well, it has pretty much everything. It operates at a very high frequency; it features all the most popular communications ports; it can be set to consume very little energy; it can be programmed in a wide array of programming languages. It isn’t an overstatement to say that the BeagleBone offers boundless possibilities in many areas, from fast-reacting systems and processing-heavy programs to low-consumption vehicles. Following are suggestions for four amazing projects for the BeagleBone.

Article / Updated 03-26-2016

Two of the most popular open-source hardware boards are the BeagleBone Black and the Raspberry Pi. Both boards are known for being easy to set up and inexpensive, as well as great to use for getting started in electronics and programming. The Raspberry Pi dives deeper into the world of computation, whereas the BeagleBone Black features the best of the worlds of computation and electronics, with added emphasis on electronics. Comparing hardware Each board has strengths and weaknesses. Some projects are better on one board than on the other. BeagleBone Black (Revision C) Raspberry Pi (Model B+) Processor AM3358 ARM Cortex A-8 ARM1176JZF-S Speed 1 GHz 700 MHz RAM 512MB 512MB Storage 4GB onboard, microSD card microSD card Resolution 1920 x 1080 pixels 1920 x 1200 pixels USB ports 1 4 Audio port Micro HDMI HDMI, Composite Video port Micro HDMI HDMI, Composite Ethernet RJ45 port RJ45 port General purpose input/output (GPIO) 65 pins 40 pins Default operating system Linux (Debian) Linux (Raspbian) BeagleBone Black advantages Setting up the BeagleBone Black is really simple, whereas setting up the Raspberry Pi can quickly become tedious. That fact, along with the fact that the BeagleBone Black features 65 input and output pins and a ridiculously huge number of supported interfaces, generally makes the BeagleBone Black the go-to choice for projects that deal with electronics more directly and in a more complex sense. Tasks such as reading from external sensors, commanding actuators (such as motors or light systems), and networking are not only simpler on the BeagleBone Black but also more efficient. Raspberry Pi advantages For complex multimedia and Linux-based projects, the Raspberry Pi is often the better choice because it’s graphical and because its audio capabilities are better than the BeagleBone’s by a solid margin.

Article / Updated 03-26-2016

Having an Ethernet cable connected to your BeagleBone ensures that you have access to the Internet. This access is really handy, as you may need to install or update an application or work on Internet-related projects. Establishing this type of communication also enables you to access your BeagleBone from any other devices as long as you remain connected to the same network. Simply open your terminal window or PuTTY, and you can establish an SSH (secure shell) connection in a similar fashion to the method you use to connect via USB. Windows You need a free application called PuTTY to establish an SSH connection using a Windows PC. Here’s how to install it: Open your web browser. Go to the free PuTTY download. Click the putty.exe file to download it. Run the putty.exe file to install the software. With PuTTY installed, you need to power up your BeagleBone and follow these steps: Power up your BeagleBone with a Mini USB cable or with a 5V DC power supply. Any time that it is possible, it’s recommended that you power your BeagleBone with a DC power supply so that you are guaranteed to not have any issues with power. Make sure that the outer ring of the plug is ground and the center is 5V. Connect an Ethernet cable from your router to your BeagleBone. Open PuTTY. In the PuTTY Configuration dialog box, select SSH. Type beaglebone as the host. The port needs to remain at the default number, which is 22. Your dialog box should have the settings shown. Click Open. When you’re asked to log in, type root and press Enter. When you’re asked to type a password, press Enter. By default, no password is set. When you connect your computer to your BeagleBone for the very first time, you’re prompted by a message warning you that you’re attempting to establish a connection with an unknown host. This message just means that your computer and the BeagleBone aren’t friends yet. Simply click OK to proceed. Mac OS X and Linux In Mac OS X and Linux, you can use the default terminal window to establish an SSH communication, because SSH comes in all Unix-based OSes. Follow these steps: Power up your BeagleBone with a Mini USB cable or with a 5V DC power supply. Any time that it is possible, it’s recommended that you power your BeagleBone with a DC power supply so that you are guaranteed to not have any issues with power. Make sure that the outer ring of the plug is ground and the center is 5V. Connect an Ethernet cable from your router to your BeagleBone. Open a new window, as follows: On a Mac, navigate to /Applications/Utilities and double-click Terminal to open a new Terminal window. In Linux, press Ctrl+Alt+T to open a new terminal window. Type sudo ssh [email protected]. Enter your computer password, and type yes. When you’re asked to type a password, press Enter or Return. By default, no password is set. The window should look like this: When you connect your computer to your BeagleBone for the very first time, you’re prompted by a message warning you that you’re attempting to establish a connection with an unknown host. This message just means that your computer and the BeagleBone aren’t friends yet. Simply click OK to proceed.

Article / Updated 03-26-2016

The serial port is a way to send data between the BeagleBone Black and another device. Establishing a serial communication between your computer and your BeagleBone Black requires a USB-to-TTL Serial cable. For most applications, connecting the BeagleBone Black via SSH over USB is the way to go. This connection technique allows you to send data to and from many devices other than PCs, which may be useful if you’re experiencing booting problems or networking issues. You can see what’s happening to your board right after plugging in the power with a serial debugger. Windows If you use Windows, you need to download and install a free application called PuTTY. Here’s how to install it: Open your web browser. Go to the free PuTTY download. Click the putty.exe file to download it. Run the putty.exe file to install the software. Before you power up your board, you need to make a few connections: Connect the USB side of the TTL cable to your computer. Connect the wires to the J1 headers on your BeagleBone Black as shown: Black wire to Pin 1 Green wire to Pin 4 White wire to Pin 5 With PuTTY installed, you can establish a serial communication with your BeagleBone Black. Follow these steps: Open PuTTY. In the PuTTY Configuration dialog box, select Serial. Type the name of your BeagleBone Black’s serial port. Open Device Manager to see the serial port’s name. Press Windows+R, type devmgmt.msc, and press Enter. The name of your BeagleBone’s serial port is listed below Ports. Type 115200 in the Speed field. Click Open. Power on your BeagleBone Black with a Mini USB cable. You see all sorts of information about the booting process. When you’re asked to log in, type root and press Enter. When you’re asked to type a password, press Enter. By default, no password is set. Mac OS X and Linux In Mac OS X and Linux, you can use the default terminal window to establish a serial communication. With your BeagleBone Black unplugged, follow these steps: Open a new window, as follows: On a Mac, navigate to /Applications/Utilities and double-click Terminal to open a new Terminal window. In Linux, press Ctrl+Alt+T to open a new terminal window. Type ls /dev/tty*. Connect the USB side of the TTL cable to your computer. Connect the wires to J1 headers on your BeagleBone Black: Black wire to Pin 1 Green wire to Pin 4 White wire to Pin 5 Type ls /dev/tty*. Now you can see a new device connected to your computer — in the figure, ttyUSB0. To establish the serial communication, follow these steps: Type sudo screen /dev/ttyUSB0 115200. Power on your BeagleBone Black with a Mini USB cable. You see all sorts of information about the booting process. Enter your computer password, and press Enter or Return. When you’re asked to log in, type root and press Enter or Return. When you’re asked to type a password, press Enter or Return. By default, no password is set.

Article / Updated 03-26-2016

If your BeagleBone is running the OS through the microSD card, insert it before powering up your BeagleBone. Then follow these steps to set up your BeagleBone: Using the Mini USB cable that came with your board, connect your BeagleBone to your computer. After a few seconds, a drive called BeagleBone Getting Started should appear in your computer’s file system. Your BeagleBone comes with everything you need to get started: the drivers for its setup, as well as documentation and project examples. Go to your file system, and double-click the BeagleBone Getting Started disk. Open the file called START.htm in your default web browser. Installing drivers With the file you just opened on your web browser, click Step 2: Install Drivers in the menu on the left side of the web page. Use the appropriate installation method based on your OS (Windows or Mac OS X). If you’re using Linux, it isn’t necessary to install the drivers. Windows: If you’re using Windows, we recommend that you try to install the drivers for the 64-bit version. If that installation fails, you’re running a 32-bit version, so install the 32-bit drivers. Doing things this way guarantees that you won’t install 32-bit drivers on a 64-bit machine. Macintosh: In Mac OS X, you have to install the network and serial drivers. This process is very straightforward. After you open each driver file, you click the Next button until the installation is finished. Browsing to your BeagleBone After your drivers are installed, you need to open an URL on your web browser. Enter 192.168.7.2 in the address bar. It's recommended that you use only Google Chrome or Mozilla Firefox, because other web browsers don’t offer some JavaScript functionalities that the BeagleBone requires. Both web browsers are free to download at their official websites. If everything is working properly, you should see a green box at the top of the screen that says Your board is connected!

Article / Updated 03-26-2016

Currently, the hostname of your BeagleBone is, rather boringly, beaglebone. You may want to change it to something more personal. Doing so is also useful when you start to use more than one BeagleBone on the same network, because the hostname is the name that’s displayed to all the other users on that network. If you want to change the hostname, start by typing the following command: debian@beaglebone:~$ sudo echo 'newHostName' > /etc/hostname Your hostname is changed to the one that you prefer. The BeagleBone won’t recognize this “host,” however, so you need to edit the hosts file. To open and edit it, follow these steps: Type the following in a text editor such as nano: debian@beaglebone:~$ sudo nano /etc/hosts On the line that reads 127.0.0.1 beaglebone, change beaglebone to your new hostname Save the file, and quit nano. Reboot your BeagleBone. Your new hostname should appear during your next login. Use the arrow keys to navigate nano, and press Ctrl+O to save and Ctrl+X to exit. If you attempt to exit without saving, you’re prompted to press Y if you want to save or N if you don’t. The default debian user password is temppwd. If you want to change it, simply type the command passwd and follow the steps printed in the terminal: debian@beaglebone:~$ <b>passwd</b> Changing password for debian. (current) UNIX password: Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully debian@beaglebone:~$ The text is hidden while you write the passwords.

Article / Updated 03-26-2016

When you have your BeagleBone Black set up like a desktop computer, you can do all the regular things that you do on a computer — such as creating files and folders or running applications — without using the terminal. If you have the knack of the terminal, however, and know how much faster things can be done that way, you can easily access it. Even if you prefer doing everything in the desktop environment and using the terminal as little as possible, you still need to use it for some tasks, such as installing and updating software. To access the terminal, click the icon in the bottom-left corner of your screen. Mouse over to Accessories and click LXTerminal. The next figure shows an open terminal window. You can have several terminal windows and tabs open at the same time. Click File to generate a new terminal window or tab. You can also see the keyboard shortcuts that do the same things on the menu that appears when you click File. During an LXDE session, you may need to resize or minimize your open windows, such as the terminal. You handle this task in much the same way as you would on a Mac or Windows computer. In this terminal, you’re controlling the BeagleBone directly rather than controlling it remotely through the use of SSH. If you’ve created a emailer.py program, for example, you can run it from the terminal. Start by logging in as root and then changing to the Projects folder: sudo su cd /var/lib/cloud9/Projects python emailing.py To run the Python script from the terminal, simply type python emailing.py You can use the nano terminal text editor to view and edit your text files. When you use your BeagleBone Black to create a desktop environment, you have other text-editor options, such as Leafpad. If you are in the Projects folder, type the following command in the terminal: leafpad emailing.py Note that after you issue the command line to start Leafpad, the terminal becomes stuck; you can’t write anything in the terminal from that point on. (Well, you can, but it won’t have any effect.) That’s not a problem because you can have as many open terminal windows and tabs as you want, and only the one where you issued a command to run a program is stuck. Any other open tabs or terminal windows are still functional. When you want to terminate something that’s being run in the terminal, for example Leafpad, simply press Ctrl+C with the terminal window that’s running it open. Ctrl+C is the Cancel command when you are operating the Terminal. If you need to copy something from the Terminal, the appropriate shortcut is Ctrl+Shift+C. You can use Ctrl+Shift+X for cutting and Ctrl+Shif+V for pasting. If running the script failed, you probably don’t have the necessary permissions. When you use the BeagleBone as a desktop computer, you’re logged in as debian. Regardless, you can still run programs as root. Don’t forget to log in as root or to precede your commands with sudo: sudo python /var/lib/cloud9/emailing.py

Article / Updated 03-26-2016

Following is a handy reference that you can use to control and access your BeagleBone’s general purpose input/output (GPIOs) with the file system, BoneScript, and Python. Controlling the GPIO with the file system You can use the following commands to control the GPIO with the file system. Exporting a pin: echo 40 > /sys/class/gpio/export Setting a pin OUTPUT: echo out > /sys/class/gpio/gpio40/direction Writing a pin HIGH: echo 1 > /sys/class/gpio/gpio40/value Writing a pin LOW: echo 0 > /sys/class/gpio/gpio40/value Setting a pin INPUT: echo in > /sys/class/gpio/gpio40/direction Reading the value from an INPUT pin (returns 1 for HIGH and 0 for LOW): cat /sys/class/gpio/gpio40/value Controlling the GPIO with BoneScript You can use the following BoneScript commands to control the GPIO. Loading a BoneScript module: var b = require('bonescript'); Setting a pin OUTPUT: b.pinMode("P9_14", b.OUTPUT); Writing a pin HIGH: b.digitalWrite("P9_14", b.HIGH); Writing a pin LOW: b.digitalWrite("P9_14", b.LOW); Setting a pin INPUT: b.pinMode("P8_11", b.INPUT); Reading the value from a digital INPUT pin (returns HIGH or LOW): b.digitalRead("P8_11"); Setting a pin for pulse-width modulation (PWM) with 50 percent duty cycle: b.pinMode('P9_14', b.OUTPUT); b.analogWrite('P9_14', 0.5); Reading the value from an analog INPUT pin (returns a value between 0 and 1): b.analogRead('P9_40'); Controlling the GPIO with Python You can use the following Python commands to control the GPIO. Importing Adafruit’s BeagleBone Input Output Library: import Adafruit_BBIO.GPIO as GPIO Setting a pin OUTPUT: GPIO.setup("P9_14", GPIO.OUT) Writing a pin HIGH: GPIO.output("P9_14", GPIO.HIGH) Writing a pin LOW: GPIO.output("P9_14", GPIO.LOW) Setting a pin INPUT: GPIO.setup("P8_11", GPIO.IN) Reading the value from a digital INPUT pin (returns HIGH or LOW): GPIO.input("P8_11") Setting a pin for PWM with 50 percent duty cycle: import Adafruit_BBIO.PWM as PWM PWM.start("P9_14", 50) Setting an analog INPUT: import Adafruit_BBIO.ADC as ADC ADC.setup() Reading the value from an analog INPUT pin (returns a value between 0 and 1): analogReading = ADC.read("P9_40")