I've been attempting to control Keyboard LEDs using various methods with some success (I intend to use the LED signals from a butchered USB keyboard as a serial output - details here: http://www.electronicspoint.com/pic-programmer-made-usb-keyboard-t260458.html
Problems I've run into:
- The 'DefineDosDevice' method only works with PS2 keyboards
- DirectX methods including microsofts own example absolutely do not work
- the 'hid method' can just f*** right off! I dont even want to f***ing know!
- keybd_event and SendInput work, but there is a variable delay (at least in win7). The strange thing with this is that if the mouse is moving, the delay disappears. Can anyone tell me whats going on here? Is there some kind of output buffer and if so can I flush it? I wont get more than 2bps unless I can get round that.