On Wed, Dec 9, 2009 at 4:20 PM, stefan kersten
looks great, thanks! do you happen to have some example code for working with HID devices (mice, keyboards, etc.)?
The usb package does not support the various device classes directly. You won't find a function like "isKeyPressed ∷ Device → KeyCode → IO Bool". But you could write it based solely on functions from the usb package. Enumerate the devices connected to your system, find your HID device, open a handle (or enter a safe region), choose an interface and an alternative and finally send some sort of control request encoded in a ByteString. The actual bytes you need to send in order to discover if some key on your USB keyboard is pressed is defined somewhere in the USB HID device class specification. If you really need that kind of functionality then you could create a package "usb-hid" that offers an abstraction over the HID device class. But if you just want to know if some key is pressed then a much simpler solution would be to use a library like SDL or GLUT. Keep in mind that all functions in the usb package run in *client side*. To actually use a device (communication) you need the proper permissions, which in practice implies super-user privileges. Libraries like SDL interface with the kernel drivers and do not need such permissions (correct me if I'm wrong). Regards, Roel