Automatic(Software)Reset
Rather than requiring a physical press of the reset button before an upload, the Yún
is designed in a way that allows it to be reset by software running on a connected
computer. The reset is triggered when the Yún's virtual (CDC) serial / COM port is
opened at 1200 baud and then closed. When this happens, the processor will reset,
breaking the USB connection to the computer (meaning that the virtual serial /
COM port will disappear). After the processor resets, the bootloader starts,
remaining active for about 8 seconds.
The bootloader can also be initiated by pressing the reset button on the Yún. Note
that when the board first powers up, it will jump straight to the user sketch, if
present, rather than initiating the bootloader. Because of the way the Yún handles
reset it's best to let the Arduino software try to initiate the reset before uploading,
especially if you are in the habit of pressing the reset button before uploading on
other boards. If the software can't reset the board you can always start the
bootloader by pressing the reset button on the board.
USBOvercurrentProtection
The Yún has a resettable polyfuse that protects your computer's USB ports from
shorts and overcurrent. Although most computers provide their own internal
protection, the fuse provides an extra layer of protection. If more than 500 mA is
applied to the USB port, the fuse will automatically break the connection until the
short or overload is removed.
PhysicalCharacteristics
The maximum length and width of the Yún PCB are 2.7 and 2.1 inches respectively,
with the USB connector extending beyond the former dimension. Four screw holes
allow the board to be attached to a surface or case. Note that the distance between
digital pins 7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing
of the other pins. Weight of the board is 32 g.
PreviousVersions
Do you own a past an old version of this product? If you bought your Arduino Yún
before Oct 2014, please check the Yún Open WRT OS Getting Started Page. If you
bought it in 2015 check Arduino Yún Linino OS Getting Started page.
https://store.arduino.cc/usa/arduino-yun 12-1-17
