How do I get started to setup a "RACHEL Pi"?

Raspberry Pi in a case
1 - Get your Raspberry Pi

First of course you need a Raspberry Pi (you may already have one, or many of them.., so in this case just skip this step..). If you never heard about it, it is basically a credit-card sized Linux box, and you can find all about it at www.raspberrypi.org. If you need to buy one you have to also buy the power supply. A plastic case is strongly recommended. Also, get the Model B, which has 512Mb RAM.

      Required Parts:

       Total Cost: Under $90


rachel-pi_card
2 - Get a 32 or 64 GB SD Card ready.

You'll need at least a 32 GB SD flash memory card, to host the operating system and the RACHEL-Pi educational package. It is recommended to get a fast card. For instance, I use for RACHEL-Pis a SanDisk Extreme 32 GB SDHC Class 10 card, which has up to 45 MB/s read-write speeds.

Don't try to save money on the SD card/s. A known name brand, with fast read-write speeds, will save you a lot of headaches when used with a Raspberry Pi.

3 - Download the "RACHEL-Pi" card image.

Think of the image as an exact copy of the whole hard drive of your PC or Mac, everything in just one file. In this case you will use this "image" file to then burn it, or write it, to your own SD card, making so an exact clone of an original RACHEL-Pi server SD card I have with me. You are either going to download it by FTP or through BitTorrent Sync (recommended):

BitTorrent Sync is now available for better reliability and consistency of download. Please consider familiarizing yourself with BitTorrent Sync. We do not support FTP downloads for all versions.

Version Language BitTorrent Sync Code
RACHEL 32GB Pi English BPFDH6A7Y7276YM5LUNMSTBIGENHZIHNJ
RACHEL 64GB Pi English BWVIWEJY74CKTOALRI4H4NHEJZTDSULQT
RACHEL (ESP) 32GB Pi Espanol B4VFCSSVW5SA73YKKBUUA67U6YLDXYPWI
RACHEL (ESP) 64GB Pi Espanol BTYBOVEEBWDVAEETM6YNXNVQZQDGBJWYU

The 64GB versions of RACHEL (in both cases) replace Khan Academy on a stick w/ an expanded library offered in KA-Lite (as well as exercises).  In english, 64GB image also includes GCFlearnfree.org (computer training videos).



If you would prefer to use the FTP, please try the following instructions

  • FTP connection: Host = ftp.worldpossible.org , Username = anonymous@worldpossible.org, Password: anonymous, port = 21 (default).

A very good and free FTP client for Windows, Mac and Linux is FileZilla ( filezilla-project.org). It has very important features (Keep-alive, auto reconnect) for downloading very large files like this.

Sample FTP login using FileZilla:

FileZilla connection

 

Once connected you'll see the files in the server available for FTP download. Go to the "rachel" folder and drag the rachel_pi_32_20130924.img file to a folder in your computer. This file, of about 32 GB size, contains an instance of the RACHEL Raspberry Pi image. Example using FileZilla on Windows:

 

r_pi_32_ftp_download

 

The FTP download will start.

 

WARNING: This is a very large file, 32 GB, which may take a very long time to download, many hours if you don't have a fast Internet connection.

 

Important: if you want to verify the integrity of the very large downloaded file, which is strongly recommended to make sure that it has arrived intact during the long download process, this is its md5 checksum:

  • For the rachel_pi_32_20130924.img file: dd0bf2bf156d676db0125b98152aecdd

To verify if the MD5 checksum of the downloaded file matches the checksum of the original file (listed above) you can use on Windows a free tool like WinMD5Free (www.winmd5.com). Sample screenshot:

 

r_pi_32_md5

 

 

4 - Write the downloaded RACHEL-Pi image to your SDHC memory card.
This is what you need to do (example on Windows):
  • Download Win32DiskImager, a free Windows software, from http://sourceforge.net/projects/win32diskimager/files/latest/download
  • Unzip it and install it in your PC/laptop.
  • Plug your SD card into your PC.
  • Start the Win32DIskImager software (Win32DiskImager.exe)
  • Select the downloaded rachel_pi_32_20130924.img file and the drive where the SD card is inserted. Then click the "Write" button:
  •  

    r_pi_32_img_write

     

    Now you have a card with the OS and the pre-configured RACHEL-Pi content package ready for action.

     

    5 - Setup your RACHEL-Pi server.
    • Insert the SD card into the Raspberry Pi slot
    • With the Raspberry Pi already plugged to your network or wireless router start the Pi, just plugging the power (If you want to login to this RACHEL-Pi distribution please use username: pi , password: rachel . Of course you can change the password afterwards to anything you want..).

    Sample setup with a $45 consumer wireless router:

    Pi server router setup

     

    Scanny
    • Find out the IP address of the Raspberry Pi:
      • If you plug a TV to the Pi via an HDMI cable or composite cable you'll see the IP address at the bottom of the boot messages on the screen.
      • Or from a terminal on the pi use the ifconfig command:
      • pi@raspberrypi ~ $ ifconfig
        eth0      Link encap:Ethernet  HWaddr b8:27:eb:ce:67:31
                  inet addr:10.0.1.20  Bcast:10.0.1.255  Mask:255.255.255.0
                  UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        
        
        The IP address in the example above is 10.0.1.20
      • If you have the Pi plugged to the router you can use another computer or device connected to the same network to see what IP address the Pi was assigned.
        For instance you can just you a phone connected to the same wi-fi network and use an app to scan it and find out the connected computers. The one which vendor name is "Raspberry Pi Foundation" is your Raspberry Pi. Make note of the IP address, 10.0.1.20 in this example. (Using the Scany iPhone app for this screenshot on the right).
      • You can also use the router interface to find our the connected devices and get the IP from there.
      • Note: later, if you use this solution in a semi-permanent setup, like in a school, you can assign in the router a static IP to the RACHEL-Pi server, so the IP will be always the same, and the users/students can also bookmark it in their browsers.

     

    6 - Start using the RACHEL server.
    • Now a computer or device connected to this network, wired or wirelessly (wi-fi), will be able to access and play the RACHEL content, just by entering the IP address of the Raspberry Pi in a browser URL field:
    •  

      From a PC web browser:

       

      r_pi_32_ip_address_browser

       

     

    • Now, after having directed your students (or just yourself) to the IP address of the RACHEL-Pi server people can start browsing and using the RACHEL educational content as needed.
    •  

      r_pi_32_browser

     

    7 - Option: Use your RACHEL-Pi as a Wi-Fi hotspot

    rachel-pi_hotspot

    The latest RACHEL-Pi image already includes all the software necessary to use the Raspberry Pi as a Wi-Fi hotspot. This pre-configured software is running all the time on your RACHEL-Pi package: You just need to plug a USB WiFi Adapter to a USB port and start the Raspberry Pi.

    It will automatically create a Wi-Fi hotspot called "RPI", to which you can connect from any Wi-Fi enabled device, like a tablet, laptop or smart phone, and access wirelessly the RACHEL content, without the need to use any other network device, like a wireless router. Perfect for an instant setup of a wireless educational hotspot.

    Another advantage is that you'll need just the Raspberry Pi power adapter and cable, which will in this case power the Raspberry Pi computer and the USB dongle-based Wi-Fi hotspot.

    Simple steps:

      ka-pi_with_wifi_adapter
    • Plug a USB WiFi adapter into a USB port of the Raspberry Pi. The adapter has to support the Access Point or master mode. There are many models of non-expensive ones based on Ralink chipsets.

      Sample supported adapters:

      Amazon $7

      dx.com $6

    • Power up the Raspberry Pi (plug the power cable)
    • From a Wi-Fi computer or mobile device connect to the "RPI" Wi-Fi network:
    •  

      ka-pi_ap_wifi

       

    • From the computer or device enter the 192.168.10.1 address in the browser URL window:
    •  

      ka-pi_ap_browser

       

    • Navigate the RACHEL content.

     

    Note: The above Wi-Fi setup can be used together with the previous network setup. So you can have the Raspberry Pi running RACHEL-Pi connected via network cable with a router and at the same time running the Wi-Fi hotspot from the Pi. So some students can connect to the local network setup by the router and to the "RPI" wireless network created by the USB Wi-Fi adapter.

     

    What web browsers to use with RACHEL?

    This "Khan Academy on a Stick" content included in RACHEL, with almost 3,000 video lectures, uses HTML 5 video in mp4 format using H.264 video and AAC audio codecs. So to be able to play these videos you need to use an modern HTML 5 compatible browser version that also supports this video format.

    You can see a list of supported browsers here The ones under the H.264 column and highlighted in Green are very likely to play fine the videos in this distribution.

    For instance, as per today, Windows Internet Explorer 9+ and Chrome work great. Latest versions of Firefox (22+) for Mac and Windows work fine also. On the Mac, Safari, Chrome and Firefox 22+. On iOS devices (iPads, iPhones, iPod Touch) everything plays great with OS Safari: the videos can also be expanded full screen, rotated, etc. On Linux Chrome and Konqueror, on Android, well, it is a long story.., but please try yourself (there are at this time thousands of combinations of hardware-Android software versions out there. On some quality ones they play great for instance with Firefox for Android.)

    Other pieces of content part of RACHEL include Flash animations, which will be played as well by the above browsers. Though those Flash animations won't play on iOS devices (iPads, iPhones) as Apple does not support Adobe Flash on iOS.

    You can see a live online RACHEL instance at rachel.worldpossible.org . Very useful to visualize the whole content that you'll have then available in your RACHEL distribution, to be used in locations with no Internet access. Also to try different devices and browsers.

     

     

    Problems downloading or setting up RACHEL-Pi?

    Please do not hesitate to contact us should you have problems to download or setup RACHEL-Pi. You can contact us as described in the About page and we'll be happy to respond.

     

    Other Notes

    • A choice had to be made about the videos format. There is no single video format and video/audio encoding that can be played in all web browsers and operating systems out there (This table online shows which video formats are likely to be supported by a given browser). In this case H.264 video and ACC audio encoded videos in an mp4 container was chosen. This can be played on latest versions of modern browsers supporting HTML 5, as well as iOS devices (iPads, iPhones, iPod Touch) and Android devices. See list of supported browsers in the About page.
    • Most of the videos in this distribution are encoded in a relatively low bitrate, on purpose. This makes their file size fairly small, and makes possible as in this case to have a package for the RACHEL Pi that includes the OS and lots of educational content that fits in a 32 GB memory card. The RACHEL servers have been deployed in hundreds of remote locations around the world, and a reduced overall size has proven critical on the ground for downloading, installing on devices with reduced storage, cloning, etc.