Repeated keystroke "w" for Agar.io

I've been searching for the relevant articles on the Internet and found nothing useful. Maybe I'm too stupid to understand.

I would like to create a script that automatically keep pressing the "W" key, like wwwwwwwwwwwwwwwwwwwwwwwwwww, endlessly and as quick as possible when I press and hold the key, and it ends when I release the key.

"defaults write -g ApplePressAndHoldEnabled -bool false" doesn't work in this case.

Thank you very much in advanced.

Solution 1:

Karabiner:

  <item>
    <identifier>private.w2wRepeat</identifier>
    <name>Turn W key to W key repeat</name>
    <autogen>
      __KeyToKey__
      KeyCode::W,
      KeyCode::W,
      DelayUntilRepeat::RawValue::1,
      KeyRepeat::RawValue::1,
    </autogen>
  </item>