A company on eBay is auctioning off pieces of an old supercomputer cluster someone had built from Jetson TK1s and Intel NUCs. The boards are old, but you get a bunch of them pretty cheap so I bought one since cheap SBCs are always handy.
The Jetsons are a nice platform for getting one’s feet wet with CUDA for vision and deep learning on a mobile (e.g. robotic) platform. You can always step up to newer modules (Nano, TX2, etc.) if you need more power, but the TK1 is a nice board with 2GB RAM and 16GB eMMC flash (11GB free) running Ubuntu 14.04 linux (you can upgrade to 16.04).
The boards arrive configured for network booting (PXE) and you need to change that if you want to boot into ubuntu from the internal eMMC disk. To do that, you’ll need to connect to the serial port using a null modem cable. The unit starts out running u-boot; you can interact with it using a serial terminal (PuTTY, TeraTerm, etc.) configured for 115kbps, 8 data bits, No parity, 1 stop bit. Press any key to stop the automatic boot within 3 seconds (it prompts you), then you’re at the u-boot prompt. You can change the boot target (default is pxe) using the following commands:
setenv boot_targets mmc0
Then when you boot, it will automatically launch ubuntu from the eMMC drive (mmc0) and you can interact with it using an HDMI monitor and USB keyboard/mouse. See here for more useful info on u-boot configuration. The default user name is ubuntu and the password is also ubuntu.
NVidia has an active developer forum where you can find answers to almost anything. For information on the GPIO header see here and also the Jetduino project. Another great site is JetsonHacks.
To install the latest JetPack (integrates lots of CUDA/NVidia support) see here.