Siyu,
There is a configuration file that you need to touch between compiling for the End point and the Access point.
The file is called "smpl_config.dat" and you need to find
-DTHIS_DEVICE_ADDRESS="{0x78, 0x56, 0x34, 0x12}"
and change the address to some different. The requirement is that no two nodes on a SimpliciTI network can have the same MAC address.
so what about
-DTHIS_DEVICE_ADDRESS="{0x79, 0x56, 0x34, 0x12}"
Regards,
/TA