user43378: Is there any "easy" way to emulate USB keyboard or gamepad using digital pins on Arduino Mega? I looked at Uno-Joy/Mega-Joy, but I dont find firmware changes appealing.

user4143: There is (or was) an implementation of software-only USB for the Arduino. I think it was called V-USB, though I am having trouble finding it now.
I think it may be this library though nothing has happened with that for a number of years.
Personally, I wouldn't recommend it, though, and would suggest using a board with a real USB interface, such as the Arduino Leonardo, chipKIT Lenny, or Teensy 3.x.

43378: <p>Is there any "easy" way to emulate USB keyboard or gamepad using digital pins on Arduino Mega? I looked at Uno-Joy/Mega-Joy, but I dont find firmware changes appealing.</p>
 4143: <p>There is (or was) an implementation of software-only USB for the Arduino. I think it was called V-USB, though I am having trouble finding it now.</p>

<p>I think it may be <a href="https://github.com/gloob/vusb-for-arduino" rel="nofollow noreferrer">this library</a> though nothing has happened with that for a number of years.</p>

<p>Personally, I wouldn't recommend it, though, and would suggest using a board with a real USB interface, such as the Arduino Leonardo, chipKIT Lenny, or Teensy 3.x.</p>
