CC2640 广播数据构成分析

第二章 CC2640广播数据构成
第一步：将SimpleBLEPeripheral例程烧录到蓝牙中然后就开启广播之旅了。。。。。。。。。
用Packet Sniffer
抓包



1 2 3 4 5 6 7 8 9 10

下标为1 P.nbr
表示为接收数据包个数。
下标为2Time(us)表示从接收第一个数据包开始计时，每接一个包的间隔。故第一个为0，第二个为108003us，所以广播间隔大概为100ms。在此处有定义
// Advertising interval when device is discoverable (units of 625us, 160=100ms)

#define DEFAULT_ADVERTISING_INTERVAL 160
当改变DEFAULT_ADVERTISING_INTERVAL的值为320时，结果为：



此时广播间隔为205006us，即约为200ms。
下标为3 Channel
为广播通道，0X25十进制为37.
{

uint8_t AdvMap = GAP_ADVCHAN_37;

GAPRole_SetParameter(GAPROLE_ADV_CHANNEL_MAP, sizeof(uint8_t), &AdvMap);

}
通过改变AdvMap的可以设置专用广播信道。默认的情况下为GAP_ADVCHAN_ALL所有信道都在广播。建议在实际使用是使用默认，这样可以提高抗干扰能力。
GAP_ADVCHAN_37可以在GAP.h中找。
/** @defgroup GAP_ADVCHAN_DEFINES GAP Advertisement Channel Map

* @{

*/

#define GAP_ADVCHAN_37 0x01 //!< Advertisement Channel 37

#define GAP_ADVCHAN_38 0x02 //!< Advertisement Channel 38

#define GAP_ADVCHAN_39 0x04 //!< Advertisement Channel 39

#define GAP_ADVCHAN_ALL (GAP_ADVCHAN_37 | GAP_ADVCHAN_38 | GAP_ADVCHAN_39) //!< All Advertisement Channels Enabled

/** @} End GAP_ADVCHAN_DEFINES */
下标为4Access Address
为Dongle 自己MAC地址。
下标为5Adv PDU Type
广播报文类型为ADV_IND 解释如下
#define GAP_ADTYPE_ADV_IND 0x00 //!< Connectable undirected advertisement

可非定向广播连接。
在程序中的位置为
static void gapRole_init(void)

{

// Register the current thread as an ICall dispatcher application

// so that the application can send and receive messages.

ICall_registerApp(&selfEntity, &sem);

gapRole_state = GAPROLE_INIT;

gapRole_ConnectionHandle = INVALID_CONNHANDLE;

// Get link DB maximum number of connections

linkDBNumConns = linkDB_NumConns();

// Setup timers as one-shot timers 分派一个时钟。

Util_constructClock(&startAdvClock, gapRole_clockHandler,

0, 0, false, START_ADVERTISING_EVT);

Util_constructClock(&startUpdateClock, gapRole_clockHandler,

0, 0, false, START_CONN_UPDATE_EVT);

Util_constructClock(&updateTimeoutClock, gapRole_clockHandler,

0, 0, false, CONN_PARAM_TIMEOUT_EVT);

// Initialize the Profile Advertising and Connection Parameters

gapRole_profileRole = GAP_PROFILE_PERIPHERAL;

VOID memset(gapRole_IRK, 0, KEYLEN);

VOID memset(gapRole_SRK, 0, KEYLEN);

gapRole_signCounter = 0;

gapRole_AdvEventType = GAP_ADTYPE_ADV_IND;

gapRole_AdvDirectType = ADDRTYPE_PUBLIC;

gapRole_AdvChanMap = GAP_ADVCHAN_ALL;

gapRole_AdvFilterPolicy = GAP_FILTER_POLICY_ALL;

// Restore Items from NV

VOID osal_snv_read(BLE_NVID_IRK, KEYLEN, gapRole_IRK);

VOID osal_snv_read(BLE_NVID_CSRK, KEYLEN, gapRole_SRK);

VOID osal_snv_read(BLE_NVID_SIGNCOUNTER, sizeof(uint32_t),

&gapRole_signCounter);

}

下标为6 Adv PDU Header
报头。

广播类型是通用广播（Type 为0
见AdvPDU Type）。

地址类型都是public即gapRole_AdvDirectType = ADDRTYPE_PUBLIC;见上图。（TxAdd和RxAdd都为0）。

长度字段指示PDU-Length 指AdvA + AdvData之和。
下标为7的AdvA
为本机MAC地址。在第一章中已经提到。
下标为8的AdvData为广播数据，可以在
// GAP - Advertisement data (max size = 31 bytes, though this is

// best kept short to conserve power while advertisting)

static uint8_t advertData[] =

{

// Flags; this sets the device to use limited discoverable

// mode (advertises for 30 seconds at a time) instead of general

// discoverable mode (advertises indefinitely)

0x02, // length of this data

GAP_ADTYPE_FLAGS,

DEFAULT_DISCOVERABLE_MODE | GAP_ADTYPE_FLAGS_BREDR_NOT_SUPPORTED,

// service UUID, to notify central devices what services are included

// in this peripheral

0x03, // length of this data

GAP_ADTYPE_16BIT_MORE, // some of the UUID's, but not all

#ifdef FEATURE_OAD

LO_UINT16(OAD_SERVICE_UUID),

HI_UINT16(OAD_SERVICE_UUID)

#else

LO_UINT16(SIMPLEPROFILE_SERV_UUID),

HI_UINT16(SIMPLEPROFILE_SERV_UUID)

#endif //!FEATURE_OAD

};

中找到答案。