(To download KA-Pi en Español, see the HOW TO - KA-Pi Spanish version)
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.
You'll need a 16 GB SD flash memory card, to host the operating system and the KA-Pi package. It is recommended to get a fast card. For instance, I use for KA-Pis a SanDisk Extreme 16 GB SDHC Class 10 card, which you can get at Amazon for less than U$S 19, and has up to 45 MB/s read-write speeds.
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 KA-Pi server SD card I have with me. You are going to download it by FTP:
Example: FTP download on Windows:
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:
Once connected you'll see the files in the server available for FTP download. Go to the "pi" folder and drag the kaos_pi_16_20130921.img file to a folder in your computer. Example using FileZilla on Windows:
The FTP download will start.
Linux Example: FTP command line download:
Download from Linux using wget. Example:
WARNING: This is a very large file, which may take a very long time to download, even hours if you don't have a fast Internet connection.
Important: if you want to verify the integrity of this very large downloaded file, which is strongly recommended to make sure that it has arrived intact during the long download process, this is the file md5 checksum:
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:
On Linux/UNIX you can just run the md5sum command, like: $ md5sum kaos_pi_16_20130921.img
Sample setup with a $45 consumer wireless router:
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:1The IP address in the example above is 10.0.1.20
The latest KA-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 KA-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 Khan Academy videos, 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.
Sample supported adapters:
Note: The above Wi-Fi setup can be used together with the previous network setup. So you can have the Raspberry Pi running KA-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.
Please do not hesitate to contact me should you have problems to download or setup KA-Pi. You can contact me as described in the About page and I'll be happy to respond.