Z-Stack User's Guide - CC2430ZDK
F8W-2005-0036 Version 1.4.3
10
Copyright
2005-2007 Texas Instruments, Inc. All rights reserved.
When each SampleApp device starts up, it is subscribed to Group 1 and will receive and process
messages sent to Group 1 from any other device. In this demonstration, a device will flash its
LED1 (green) when a Group 1 message is received. So, when the network is initially started up,
pressing button SW1 on any device will broadcast a message, causing all of the other devices to
flash their LED1. Pressing button SW2 on a device toggles that device’s membership in Group 1,
allowing the user to enable/disable LED1 flashing on that device.
The discussion above assumes each device has been programmed and disconnected from the
development PC. When necessary, a target device can be controlled from the IAR IDE,
providing for standard debugging features such as breakpoints, single-stepping, viewing of
memory and register contents, etc.
7. PanID and Channel Selection
The ZigBee specification defines the use of a 14-bit Personal Area Network Identifier (PanID) to
uniquely identify a network. Z-Stack provides the user with two methods of selecting a PanID
when starting or joining a network by setting the value of
ZDAPP_CONFIG_PAN_ID
. Setting
this parameter to 0xFFFF causes a device to join the “best” network it can discover, any other
value causes it to use the exact value specified.
The IEEE 802.15.4 specification defines 16 channels in the 2.4 GHz frequency range. These
channels are assigned numbers 11 through 26. Z-Stack initially defaults to channel 11, but the
user can select a different channel by changing
DEFAULT_CHANLIST
. This parameter is a bit
map field, with each bit representing a single channel. As shown below, the initial default
channel 11 (0xB) is represented by 0x00000800 (11
th
bit in the field, starting from bit 0).
Channel Number
Bit Map Field
11
0x00000800
12
0x00001000
13
0x00002000
14
0x00004000
15
0x00008000
16
0x00010000
17
0x00020000
18
0x00040000
19
0x00080000
20
0x00100000
21
0x00200000
22
0x00400000
23
0x00800000
24
0x01000000
25
0x02000000
26
0x04000000
Table 1: Default Channel Select Bit Map
