USB is a great interface technology, allowing you to connect all sorts of devices to your Mac. One important subset of USB devices is known as HID, or Human Interface Device. One of these devices is one that you probably use every day, the keyboard. Of course there is a wide variety of other HID devices that you may have at your disposal, such as a mouse, trackball, or game controller. Normally, you just plug in the device and it works. But if you are having problems with a device, you'll need to dig deeper to see if it is working properly. Enter iHID.
iHID Shows Values Reported By Your HID Device
When you launch iHID, there will be a Device menu. Click on this, and you'll see a list of the HID devices currently connected to your Mac. The easiest is your keyboard. Select this, and you'll see a list of all the possible Elements the device can report on. In the case of a keyboard, there will be an entry for each key. Each value is normally zero, and if you press a key the value will change to one. This can help you diagnose an issue with a device since you can make sure that it is reporting the correct values to your Mac.
Things get a bit more interesting if you hook up a device like a trackball. In this case, you can see values for buttons, but can also view the values of the x and y motion of the ball, and a scroll wheel, common on many trackballs. You can also use iHID to get more information on the device, which includes the Product ID, Vendor ID, Product Name, Manufacturer, Serial Number and Version of the device.
So start taking a close look at what your HID devices are saying to your Mac and check out iHID today. Have any other Gadgets that tell you more about what your Mac is up to? Send an email to John, and he'll check it out.