Before I go too far, I'm pretty sure this is just a PEBKAC ("Problem Exists Between Keyboard and Chair") error, and not a hardware issue. But I could be mistaken. I just tried booting up and using my Udoo for the first time (I've had it for a year or so, but kept getting distracted). Unfortunately I can't seem to get the Arduino examples to work on the Udoo. They compile and upload to the Arduino just fine, but then they don't seem to actuall *do* anything. The blink example doesn't appear to flash an LED anywhere on the board (is there even an LED to flash?), and the two serial communication examples I've tried don't seem to actually send/receive any data (I've tried using GTKterm as well as the built-in serial monitor in the Arduino IDE). Setup: I've got the Arduino IDE 1.5.7 installed and patched on my laptop (running Ubuntu 14.04). I've removed the J18 jumper and connected the programming port to my laptop's USB port. Inside the Arduino IDE I have "Due (Programming Port)" selected for the board, and /dev/ttyUSB0 as the port. When I click "upload" after opening the example the output at the bottom indicated success: Code: Sketch uses 10,788 bytes (2%) of program storage space. Maximum is 524,288 bytes. Erase flash Write 11924 bytes to flash [ ] 0% (0/47 pages) [====== ] 21% (10/47 pages) [============ ] 42% (20/47 pages) [=================== ] 63% (30/47 pages) [========================= ] 85% (40/47 pages) [==============================] 100% (47/47 pages) Verify 11924 bytes of flash [ ] 0% (0/47 pages) [============ ] 42% (20/47 pages) [=================== ] 63% (30/47 pages) [========================= ] 85% (40/47 pages) [==============================] 100% (47/47 pages) Verify successful Set boot flash true CPU reset. FINE DELLE OPERAZIONI. After this the Arduino just sits there and does nothing. I've tried hitting the reset button, but that didn't do anything. As I said before, I've tried the Blink example (but I don't even know if there's an LED to blink), and I tried two serial examples. For both of the serial examples I tried using the serial monitor as well as GTK term to send/receive data. The port and baud rate appear to be configured properly in both cases. Do I need to change which port on the Arduino my USB cable is connected to? (I tried this briefly, but when connecting the other USB port dmesg didn't indicate that it registered anything being connected.) Do I need to (re)move additional jumpers, or change USB cable ports to get the UDOO <--> external PC communication working? And is there an LED that can be controlled by the Arduino on the board anywhere (and if so do I need to change the example code to set the correct pin)? This is my first time working with Arduino boards, but I do have a fair bit of experience working with other embedded systems (mostly AVR boards, working with avr-gcc and either avrdude or sending raw binaries to the bootloader with gtkterm). I suspect that the issue is with me and just doing something wrong/not knowing enough about how Arduinos are supposed to work. If anyone can point me in the right direction I'd really appreciate it. Thanks a lot for the help!