Logitech Wireless Presenter R400/R800 is initially designed for Microsoft PowerPoint on Windows. As one of Apple Keynote user, it is annoying that this device is not fully compatible; Play Slide button and Blank button don't work. This kernel extension aims to make Logitech Wireless Presenter R400/R800 compatible with Apple Keynote.
You can compile from the source code, put LogitechWirelessPresenter.kext to /System/Library/Extensions and run 'sudo kextutil /System/Library/Extensions/LogitechWirelessPresenter.kext'
Note that for OS X 10.11 onwards, you need your developer account to sign the kernel extension and put it to /Library/Extensions. Otherwise, you need to disable System Integrity Protection.
Reference: https://developer.apple.com/library/mac/documentation/Security/Conceptual/System_Integrity_Protection_Guide/KernelExtensions/KernelExtensions.html https://developer.apple.com/library/mac/documentation/Security/Conceptual/System_Integrity_Protection_Guide/ConfiguringSystemIntegrityProtection/ConfiguringSystemIntegrityProtection.html#//apple_ref/doc/uid/TP40016462-CH5-SW1
Actually, Logitech Wireless Presenter R400/R800 is just a keyboard. The main idea is to capture the character sent from this device and replace when necessary.
LogitechWirelessPresenterDriver simply overrides dispatchKeyboardEvent() to replace an appropriate keys.
LogitechWirelessPresenterDriver is a subclass of IOHIDEventDriver which is a subclass of IOHIDEventService where dispatchKeyboardEvent() resides.
This source code is under MIT License.