CC2420 Asynchronous Low Power Listening Implementation
Because the Low Power Listening layer uses up extra memory footprint, it is not compiled in by default. Developers can simply define the preprocessor variable LOW_POWER_LISTENING to compile the functionality of the Low Power Listening layer in with the CC2420 stack.
If you do not compile the Low Power Listening layer in with the radio stack, you will automatically get a compiler warning that simply lets you know LPL is not enabled. This is not harmful to your compilation, and is meant to be informative so you know what you're getting.
