secs=PsychHID(‘KbTriggerWait’, KeysUsage, [deviceNumber])
Scan a keyboard, keypad, or other HID device with buttons, and wait for a
trigger key press.
NOTE: This function should not be called directly! Use KbTriggerWait() instead.
By default the first keyboard device (the one with the lowest device number) is
scanned. If no keyboard is found, the first keypad device is scanned, followed
by other devices, e.g., mice. Optionally, the deviceNumber of any keyboard or
HID device may be specified.
The ‘KeysUsage’ parameter must specify the keycode of a single key to wait for
on OS/X. On Linux and Windows, ‘KeysUsage’ can be a vector of trigger key codes
and the wait will finish as soon as at least one of the keys in the vector is
On MS-Windows XP and later, it is currently not possible to enumerate different
keyboards and mice separately. Therefore the ‘deviceNumber’ argument is mostly
useless for keyboards and mice, usually you can only check the system keyboard
OSX: This function is unsupported. You must use KbTriggerWait() instead.