点播即点对点通信,也就是在两个设备之间进行通信，不允许有第三个设备收到信息。
点播描述的就是网络中两个节点之间相互通信的过程，通过16bit短地址来确定通信对象。
- step 1 定义点播方式
打开SampleApp.c文件,找到组播、广播的定义
afAddrType_t SampleApp_Periodic_DstAddr;
afAddrType_t SampleApp_Flash_DstAddr;
按照上述格式添加点播定义
afAddrType_t SampleApp_PointToPoint_DstAddr;//定义点对点通信
在函数void SampleApp_Init( uint8 task_id )中配置SampleApp_PointToPoint_DstAddr的相关参数（可参考对SampleApp_Periodic_DstAddr和SampleApp_Flash_DstAddr的配置）:
SampleApp_PointToPoint_DstAddr.addrMode = (afAddrMode_t)afAddr16Bit;//地址类型为点播地址
SampleApp_PointToPoint_DstAddr.endPoint = SAMPLEAPP_ENDPOINT;
SampleApp_PointToPoint_DstAddr.addr.shortAddr = 0x0000;//发送给协调器
- step 2 添加点对点发送函数
复制函数void SampleApp_SendPeriodicMessage( void )，修改相应的变量即可
/*********************************************************************
* @fn SampleApp_SendPointToPointMessage
*
* @brief Send the point to pont message .
*
* @param none
*
* @return none
*/
void SampleApp_SendPointToPointMessage()
{
uint8 data[10]={'0','1','2','3','4','5','6','7','8','9'};//定义发送内容
// uint8 data[10]="0123456789";//上述方式二选一
if(AF_DataRequest(&SampleApp_PointToPoint_DstAddr,&SampleApp_epDesc,
SAMPLEAPP_POINTTOPOINT_CLUSTERID,
10,
data,
&SampleApp_TransID,
AF_DISCV_ROUTE,
AF_DEFAULT_RADIUS) == afStatus_SUCCESS)
{
}
else
{
// Error occurred in request to send.
}
}
函数实现后请在SampleApp.c文件开头添加函数声明
void SampleApp_SendPointToPointMessage(void);
除此之外，还要添加SAMPLEAPP_POINTTOPOINT_CLUSTERID的定义，具体位置可通过在SAMPLEAPP_PERIODIC_CLUSTERID上右键Go to definition of SAMPLEAPP_PERIODIC_CLUSTERID来确定。
#define SAMPLEAPP_POINTTOPOINT_CLUSTERID 3
将宏定义SAMPLEAPP_MAX_CLUSTERS的值更改为３
#define SAMPLEAPP_MAX_CLUSTERS 3
找到函数uint16 SampleApp_ProcessEvent( uint8 task_id, uint16 events )，在周期性事件SAMPLEAPP_SEND_PERIODIC_MSG_EVT中调用点对点通信发送函数，同时注释掉原有的SampleApp_SendPeriodicMessage();函数：
if ( events & SAMPLEAPP_SEND_PERIODIC_MSG_EVT )
{
// Send the periodic message
//SampleApp_SendPeriodicMessage();//周期广播发送函数
SampleApp_SendPeriodicMessage(); //点对点通信发送函数
// Setup to send message again in normal period (+ a little jitter)
osal_start_timerEx( SampleApp_TaskID, SAMPLEAPP_SEND_PERIODIC_MSG_EVT,
(SAMPLEAPP_SEND_PERIODIC_MSG_TIMEOUT + (osal_rand() & 0x00FF)) );
// return unprocessed events
return (events ^ SAMPLEAPP_SEND_PERIODIC_MSG_EVT);
}
- 修改消息接收ID
在函数void SampleApp_MessageMSGCB( afIncomingMSGPacket_t *pkt )中，修改clusterId，将原有周期发送的SAMPLEAPP_PERIODIC_CLUSTERID更改为点对点通信的SAMPLEAPP_POINTTOPOINT_CLUSTERID，然后将接收的数据打印到串口，具体代码如下：
void SampleApp_MessageMSGCB( afIncomingMSGPacket_t *pkt )
{
uint16 flashTime;
switch ( pkt->clusterId )
{
//case SAMPLEAPP_PERIODIC_CLUSTERID:
//break;
case SAMPLEAPP_POINTTOPOINT_CLUSTERID:
HalUARTWrite(0,"Point_To_Point Communication\n",29);
//此处不要用sizeof计算字符串长度，否则会导致串口显示的数据出错或者不完整
HalUARTWrite(0,pkt->cmd.Data,pkt->cmd.DataLength);//打印收到的数据
HalUARTWrite(0,"\n",1);//换行
break;
case SAMPLEAPP_FLASH_CLUSTERID:
flashTime = BUILD_UINT16(pkt->cmd.Data[1], pkt->cmd.Data[2] );
HalLedBlink( HAL_LED_4, 4, 50, (flashTime / 4) );
break;
}
}
- 注释协调器的周期事件
协调器不需要周期性发送数据，在函数uint16 SampleApp_ProcessEvent( uint8 task_id, uint16 events )注释掉协调器的周期性事件
if ( //(SampleApp_NwkState == DEV_ZB_COORD)||//协调器的周期性事件
(SampleApp_NwkState == DEV_ROUTER)
|| (SampleApp_NwkState == DEV_END_DEVICE) )
{
// Start sending the periodic message in a regular interval.
osal_start_timerEx( SampleApp_TaskID,
SAMPLEAPP_SEND_PERIODIC_MSG_EVT,
SAMPLEAPP_SEND_PERIODIC_MSG_TIMEOUT );
}
- 上电测试
将修改后的程序分别以CoordinatorEB、RouterEB和EndDeviceEB的方式分别下载到三个节点中，并通过串口与PC相连，在串口中查看接收到的信息如下图。
串口测试结果
附
注意一下定义的区别和用法：
| 类型 | 定义 |
|---|---|
| 整型数组 | int num[10]={0,1,2,3,4,5,6,7,8,9}; |
| 字符数组 | char ch[10]={'0','1','2','3','4','5','6','7','8','9'}; |
| 字符串 | char string[10]="0123456789"; |
| 字符串 | char string[10]={"0123456789"}; |
| 字符串数组 | char *week[10]={"sunday","monday","tuesday","wednesday","thursday","friday","saturday"}; |