1. select atmega 16u2.
2. communicate with USB.
3. load a .hex file(arduino-keyboard.hex)
4. erase and verify device.
5. press start application.
6. And it said "Could not write to USB device."
I want to make USB keyboard.
How can I solve this problem?
(Sorry for my English. )

I have an UNO R3.
I need to make an USB keyboard.
And I know I need to make 16u2 to DFU mode.
How can I do it??????

Do I need to buy another Arduino??

I want to make this situation.
First, activate notes(window).
Second, I connect arduino Uno with computer.
Then,,,,,,, notes is filled with a(word).
Do you know any languages that can make this situation??
P.S. I am Korean. And I am not good at English.  예쁘게 봐줘용