Merge pull request #2 from arduino/HC-924_DFU-flashing-article-does-not-apply-to-Uno-WiFi-Rev2

HC-924 DFU flashing article does not apply to Uno WiFi Rev2

Author: seaxwi

content/Hardware/Generic/Flash-USB-to-serial-firmware-in-DFU-mode.md

@@ -2,7 +2,17 @@
 title: "Flash USB-to-serial firmware in DFU mode"
 ---
 
-UNO and Mega boards use either an Atmega16U2 or Atmega8U2 chip as a USB-to-serial converter, with its own firmware. The firmware can be flashed by connecting it to a computer and setting the board to **DFU mode** (Device Firmware Update).
+The following boards use either an Atmega16U2 or Atmega8U2 chip as a USB-to-serial converter:
+
+* Arduino Uno
+* Arduino Uno Rev3
+* Arduino Mega
+* Arduino Mega2560 Rev3
+* Arduino MegaADK Rev3
+
+The converter chip firmware can be flashed with a computer by setting the board to **DFU mode** (Device Firmware Update).
+
+> Note that this article does _not_ apply to the Uno WiFi Rev2, which uses a different chip with closed source firmware.
 
 ## 1. Get the firmware
 
@@ -14,8 +24,8 @@ Within the platform directory, the usb to serial firmware is found in `firmwares
 |-----------------------|------------------------------------------------|
 | Arduino Mega2560 Rev3 | Arduino-usbserial-atmega16u2-Mega2560-Rev3.hex |
 | Arduino MegaADK Rev3  | Arduino-usbserial-atmega16u2-MegaADK-Rev3.hex  |
-| Arduino UNO Rev3      | Arduino-usbserial-atmega16u2-Uno-Rev3.hex      |
-| Arduino UNO           | Arduino-usbserial-uno.hex                      |
+| Arduino Uno Rev3      | Arduino-usbserial-atmega16u2-Uno-Rev3.hex      |
+| Arduino Uno           | Arduino-usbserial-uno.hex                      |
 | Arduino Mega          | Arduino-usbserial-mega.hex                     |
 
 ## 2. Program the chip with the firmware

content/Hardware/Generic/If Arduino-UNO-or-Mega-2560-is-not-recognized-by-the-computer.md

@@ -2,7 +2,7 @@
 title: "If Arduino UNO or Mega 2560 is not recognized by the computer"
 ---
 
-Missing or corrupted **USB-to-Serial** firmware can cause UNO and Mega boards to be recognized as any of the following:
+Missing or corrupted **USB-to-Serial** firmware can cause Uno (except WiFi Rev2) and Mega boards to be recognized as any of the following:
 
 - Unknown Device
 - Composite Device

content/Hardware/Generic/Set-a-board-to-DFU-mode.md

@@ -2,15 +2,15 @@
 title: "Set a board to DFU mode"
 ---
 
-UNO and Mega boards use either an Atmega16U2 or Atmega8U2 chip as a USB-to-serial converter. By setting a board to **DFU mode** you can [upload USB-to-Serial firmware to the chip](https://support.arduino.cc/hc/en-us/articles/4408887452434-Flash-USB-to-serial-firmware-in-DFU-mode).
+Uno (except WiFi Rev2) and Mega boards use either an Atmega16U2 or Atmega8U2 chip as a USB-to-serial converter. By setting a board to **DFU mode** you can [upload USB-to-Serial firmware to the chip](https://support.arduino.cc/hc/en-us/articles/4408887452434-Flash-USB-to-serial-firmware-in-DFU-mode).
 
 1. Connect the board to your computer
 
 2. Find the RESET and GND pins for the ATmega USB-Serial Processor. They are the innermost two pins of the six located close to the Ethernet port.
 
    ![Uno front DFU reset](img/UNO-DFU-reset-pins.png)
 
-3. Briefly short the pins (follow [these instructions](#rev1) for UNO Rev1)
+3. Briefly short the pins (follow [these instructions](#rev1) for Uno Rev1)
 
 The board will reset to DFU mode.