The Dimmable Light application is part of the ZigBee Light Link (ZLL) reference application in the BitCloud SDK.
The Figure 1 shows the BitCloud SDK package. The Dimmable Light
application files are present in the \Light inside the \Applications\ZLLDemo folder.
The folder 
\BitCloud\lib
contains the BitCloud core stack library and
hardware abstraction layer(HAL) libraries to be built along with the application.Figure 1. Folder Structure
The ATSAMR21-LED-Driver project uses the 48MHz configuration which is based
on the 48MHz CPU clock configuration in the SAMR21G18A. Figure 2 captures the project workspace of the light in IAR Embedded Workbench®.
Figure 2. IAR Embedded Workspace for the
ATSAMR21-LED-Driver Board
The Figure 3 is also provided in the firmware package available with the application note.
Figure 3. Atmel Studio Project for the
ATSAMR21-LED-Driver Board
Note: The firmware is based on BitCloud SDK version 3.2.0 and the IAR™ and Atmel Studio versions are as per the BitCloud Quick Start Guide.