BLE协议栈Central 工程中与广播连接建立的事件
最近在改写BLE协议栈，需要实现实时发现周边从设备，并建立连接，获取RSSI的功能，没什么难度，但着实将各个事件好好看了一遍。曾经看到一位大神说相同的任务使用事件触发方式，不同的任务使用消息传递方式。冥冥之中突然来了感觉~
BLE进行广播和建立连接的事件主要实现是在simpleBLECentralEventCB的回调函数中:
所有使用到的变量都在联合体gapCentralRoleEvent_t中：
typedef union
{
gapEventHdr_t gap; //!< GAP_MSG_EVENT and status.
gapDeviceInitDoneEvent_t initDone; //!< GAP initialization done. 本机信息
gapDeviceInfoEvent_t deviceInfo;//!< Discovery device information event structure. 从机信息
gapDevDiscEvent_t discCmpl;//!< Discovery complete event structure.从机信息（全部）
gapEstLinkReqEvent_t linkCmpl; //!< Link complete event structure.
gapLinkUpdateEvent_t linkUpdate; //!< Link update event structure.
gapTerminateLinkEvent_t linkTerminate; //!< Link terminated event structure.
} gapCentralRoleEvent_t; // central.h
1 板级初始化事件：GAP_DEVICE_INIT_DONE_EVENT
case GAP_DEVICE_INIT_DONE_EVENT: // 初始化 // 是本机GAP层的初始化信息 在运行到GAPCentralRole_StartDevice函数被回调
{
LCD_WRITE_STRING( bdAddr2Str( pEvent->initDone.devAddr ), HAL_LCD_LINE_2 );
}
break;
详解：
作用：进行GAP层的初始化
详解：
/**
* GAP_DEVICE_INIT_DONE_EVENT message format. This message is sent to the
* app when the Device Initialization is done [initiated by calling
* GAP_DeviceInit()]. gap.h
*/
typedef struct
{
osal_event_hdr_t hdr; //!< GAP_MSG_EVENT and status
uint8 opcode; //!< GAP_DEVICE_INIT_DONE_EVENT
uint8 devAddr[B_ADDR_LEN]; //!< Device's BD_ADDR 本机的MAC地址
uint16 dataPktLen; //!< HC_LE_Data_Packet_Length 初始化长度为27
uint8 numDataPkts; //!< HC_Total_Num_LE_Data_Packets 初始化为4
} gapDeviceInitDoneEvent_t;
2 搜索从机事件（每搜到一个从机进入一次）：GAP_DEVICE_INFO_EVENT
case GAP_DEVICE_INFO_EVENT: //过程量 从机的广播数据 搜索到之后添加到从机列表中
{
char temprssiarg[4]={0};
// if filtering device discovery results based on service UUID
if ( DEFAULT_DEV_DISC_BY_SVC_UUID == TRUE )
{
if ( simpleBLEFindSvcUuid( SIMPLEPROFILE_SERV_UUID,
pEvent->deviceInfo.pEvtData,
pEvent->deviceInfo.dataLen ) )
{
simpleBLEAddDeviceInfo( pEvent->deviceInfo.addr, pEvent->deviceInfo.addrType );
}
}
}
作用： 每搜索到一个从设备时，都会进入该事件，并使用simpleBLEAddDeviceInfo加入到扫描结果列表中，deviceInfo.addr中储存着当前正被扫描到从设备地址，扫描从机的数量（simpleBLEScanRes）在simpleBLEAddDeviceInfo中增加！
详解：
**
* GAP_DEVICE_INFO_EVENT message format. This message is sent to the
* app during a Device Discovery Request, when a new advertisement or scan
* response is received. //gap.h
*/
typedef struct
{
osal_event_hdr_t hdr; //!< GAP_MSG_EVENT and status
uint8 opcode; //!< GAP_DEVICE_INFO_EVENT
uint8 eventType; //!< Advertisement Type: @ref GAP_ADVERTISEMENT_TYPE_DEFINES
uint8 addrType; //!< address type: @ref GAP_ADDR_TYPE_DEFINES
uint8 addr[B_ADDR_LEN]; //!< Address of the advertisement or SCAN_RSP 从机MAC地址
int8 rssi; //!< Advertisement or SCAN_RSP RSSI 从机RSSI值
uint8 dataLen; //!< Length (in bytes) of the data field (evtData)
uint8 *pEvtData; //!< Data field of advertisement or SCAN_RSP
} gapDeviceInfoEvent_t;
3 搜索从机事件（搜索完毕时进入一次）：GAP_DEVICE_DISCOVERY_EVENT
case GAP_DEVICE_DISCOVERY_EVENT: //结果量 // 搜索周边广播从机事件 显示搜索结果
{
// discovery complete
simpleBLEScanning = FALSE;
// if not filtering device discovery results based on service UUID
if ( DEFAULT_DEV_DISC_BY_SVC_UUID == FALSE )
{
// Copy results
simpleBLEScanRes = pEvent->discCmpl.numDevs;
osal_memcpy( simpleBLEDevList, pEvent->discCmpl.pDevList,
(sizeof( gapDevRec_t ) * pEvent->discCmpl.numDevs) );
}
char temp_simpleBLEScanRes[10]="Find : \n";
FineDeviceNum=FindDeviceNum=simpleBLEScanRes;//***************************************************************** 扫描的数量
temp_simpleBLEScanRes[8] = simpleBLEScanRes+'0';
Uart0Send_String(temp_simpleBLEScanRes,10);//***********************************
/******************************************************************************************************/
// initialize scan index to last device
simpleBLEScanIdx = simpleBLEScanRes;
IsPeriodicStart=1;
}
break;
作用：程序运行到这一步可以知道当前有多少个已经被扫描到的从设备，且它们的地址被保存到simpleBLEDevList里。
搜索结果列表 // Scan result list
static gapDevRec_t simpleBLEDevList[DEFAULT_MAX_SCAN_RES]; // 扫描结果列表
详解：
/**
* Type of device discovery (Scan) to perform.
*/
typedef struct
{
uint8 eventType;
//!< Indicates advertising event type used by the advertiser: @ref GAP_ADVERTISEMENT_TYPE_DEFINES
uint8 addrType; //!< Address Type: @ref GAP_ADDR_TYPE_DEFINES
uint8 addr[B_ADDR_LEN]; //!< Device's Address // 储存着当前搜索到的设备地址 最大可见扫描数量8
} gapDevRec_t; 搜索结果结构体
/**
* GAP_DEVICE_DISCOVERY_EVENT message format. This message is sent to the
* Application after a scan is performed.
*/
typedef struct
{
osal_event_hdr_t hdr; //!< GAP_MSG_EVENT and status
uint8 opcode; //!< GAP_DEVICE_DISCOVERY_EVENT
uint8 numDevs; //!< Number of devices found during scan
gapDevRec_t *pDevList; //!< array of device records
} gapDevDiscEvent_t; 搜索结果事件结构体
Note： 需要知道一个从设备的RSSI值，只需知道从设备的MAC地址信息在simpleBLEDevList中即可！
4 连接建立事件：GAP_LINK_ESTABLISHED_EVENT
本事件里开起一个定时器，事件连接超时断开！
case GAP_LINK_ESTABLISHED_EVENT:
{
if ( pEvent->gap.hdr.status == SUCCESS )
{
simpleBLEState = BLE_STATE_CONNECTED;
simpleBLEConnHandle = pEvent->linkCmpl.connectionHandle;
simpleBLEProcedureInProgress = TRUE;
// If service discovery not performed initiate service discovery
if ( simpleBLECharHdl == 0 )
{
osal_start_timerEx( simpleBLETaskId, START_DISCOVERY_EVT, DEFAULT_SVC_DISCOVERY_DELAY );
}
// SerialPrintString("Connected: ");
// Uart0Send_String( bdAddr2Str( pEvent->linkCmpl.devAddr ), sizeof(bdAddr2Str( pEvent->linkCmpl.devAddr )));
// for(int i=0;i<10000;i++);
for(int i=0;i<10000;i++);
LCD_WRITE_STRING( bdAddr2Str( pEvent->linkCmpl.devAddr ), HAL_LCD_LINE_2 );
for(int i=0;i<10000;i++);
// Uart0Send_String("12222",5);
//LCD_WRITE_STRING( "Connected", HAL_LCD_LINE_1 );
/*********** 2015年1月8日 不间断的搜寻周围的从设备 ************** 建立连接后读取当前的RSSI 值***********************************************************************************************/
if ( simpleBLEState == BLE_STATE_CONNECTED )
{
if ( !simpleBLERssi )
{
simpleBLERssi = TRUE;
GAPCentralRole_StartRssi( simpleBLEConnHandle, DEFAULT_RSSI_PERIOD );
}
else
{
simpleBLERssi = FALSE;
GAPCentralRole_CancelRssi( simpleBLEConnHandle );
LCD_WRITE_STRING( "RSSI Cancelled", HAL_LCD_LINE_1 );
// SerialPrintString("RSSI Cancelled\r\n");
}
}
/****************************************************************************************************************/
}
else
{
simpleBLEState = BLE_STATE_IDLE;
simpleBLEConnHandle = GAP_CONNHANDLE_INIT;
simpleBLERssi = FALSE;
simpleBLEDiscState = BLE_DISC_STATE_IDLE;
LCD_WRITE_STRING( "Connect Failed", HAL_LCD_LINE_1 );
// SerialPrintString("Connect Failed: ");
LCD_WRITE_STRING_VALUE( "Reason:", pEvent->gap.hdr.status, 10, HAL_LCD_LINE_2 );
GAPCentralRole_CancelRssi( simpleBLEConnHandle );
/*********** 2015年1月8日 不间断的搜寻周围的从设备 ************** 连接错误 主机从新进行搜索***********************************************************************************************/
simpleBLEScanning = TRUE;
simpleBLEScanRes = 0;
LCD_WRITE_STRING( "Discovering...", HAL_LCD_LINE_1 );
LCD_WRITE_STRING( "", HAL_LCD_LINE_2 );
GAPCentralRole_StartDiscovery( DEFAULT_DISCOVERY_MODE,
DEFAULT_DISCOVERY_ACTIVE_SCAN,
DEFAULT_DISCOVERY_WHITE_LIST );
/*****************************************************************************************************/
// SerialPrintValue("Reason:", pEvent->gap.hdr.status,10);
}
}
break;
详解：
/**
* GAP_LINK_ESTABLISHED_EVENT message format. This message is sent to the app
* when the link request is complete.<BR>
* <BR>
* For an Observer, this message is sent to complete the Establish Link Request.<BR>
* For a Peripheral, this message is sent to indicate that a link has been created.
*/
typedef struct
{
osal_event_hdr_t hdr; //!< GAP_MSG_EVENT and status
uint8 opcode; //!< GAP_LINK_ESTABLISHED_EVENT
uint8 devAddrType; //!< Device address type: @ref GAP_ADDR_TYPE_DEFINES
uint8 devAddr[B_ADDR_LEN]; //!< Device address of link
uint16 connectionHandle; //!< Connection Handle from controller used to ref the device
uint16 connInterval; //!< Connection Interval
uint16 connLatency; //!< Conenction Latency
uint16 connTimeout; //!< Connection Timeout
uint8 clockAccuracy; //!< Clock Accuracy
} gapEstLinkReqEvent_t;
5 连接超时事件 : GAP_LINK_TERMINATED_EVENT
case GAP_LINK_TERMINATED_EVENT:
{
simpleBLEState = BLE_STATE_IDLE;
simpleBLEConnHandle = GAP_CONNHANDLE_INIT;
simpleBLERssi = FALSE;
simpleBLEDiscState = BLE_DISC_STATE_IDLE;
simpleBLECharHdl = 0;
simpleBLEProcedureInProgress = FALSE;
LCD_WRITE_STRING( "Disconnected", HAL_LCD_LINE_1 );
// SerialPrintString("Disconnected: ");
LCD_WRITE_STRING_VALUE( "Reason:", pEvent->linkTerminate.reason,
10, HAL_LCD_LINE_2 );
// SerialPrintValue("Reason:", pEvent->linkTerminate.reason,10);
}
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