RFEasyLinkEcho例程中关于CCA的相关问题

lin shi chang

Genius 3170 points

Other Parts Discussed in Thread: CC1350

在rfEasyLinkEcho例程中，我使用的是LRM5K的配置。

1.我使用该例程不做收发切换，一边只发送，一边只接收。这样会出现什么问题吗？

2.我使用EasyLink_transmitCcaAsync(EasyLink_TxPacket *txPacket,EasyLink_TxDoneCb cb);进行发送，为什么在信号强度良好的情况下，RX还是接收不到TX发送过来的数据。

3.使用EasyLink_transmitCcaAsync(EasyLink_TxPacket *txPacket,EasyLink_TxDoneCb cb);这几个参数应该如何配置？

//! \brief Minimum CCA back-off window in units of
//! EASYLINK_CCA_BACKOFF_TIMEUNITS, as a power of 2
#define EASYLINK_MIN_CCA_BACKOFF_WINDOW 5

//! \brief Maximum CCA back-off window in units of
//! EASYLINK_CCA_BACKOFF_TIMEUNITS, as a power of 2
#define EASYLINK_MAX_CCA_BACKOFF_WINDOW 8

//! \brief The back-off time units in microseconds
#define EASYLINK_CCA_BACKOFF_TIMEUNITS 250

//! \brief RSSI threshold for Clear Channel Assessment (CCA)
#define EASYLINK_CS_RSSI_THRESHOLD_DBM -80

//! \brief Time for which the channel RSSI must remain below the specified
//! threshold for the channel to be considered idle
#define EASYLINK_CHANNEL_IDLE_TIME_US 5000

3 年多前

0 Kevin Qiu1 3 年多前

TI__Guru* 82220 points

1.不做收发切换可以用这个例程：C:\ti\simplelink_cc13x0_sdk_4_10_01_01\examples\rtos\CC1350_LAUNCHXL\easylink\rfEasyLinkTx

rfEasyLinkEcho例程功能：一个运行rfEasyLinkEchoTx，另一个运行rfEasyLinkEchoRx。将Board_1设置为每秒发送一次数据包，而Board_2设置为接收数据包，然后在经过100ms的延迟后转向并发送数据包。Board_1上的Board_PIN_LED1在能够成功发送数据包以及接收到回显信号时将进行切换。当Board_2上的Board_PIN_LED2收到数据包，然后能够重新传输时，将进行切换。

关于EasyLink_transmitCcaAsync看下这里的说明：

/*****************************************************************************
//
//! \brief Sends a Packet with non blocking call if the channel is idle.
//!
//! This function is a non blocking call to send a packet. It will check for a
//! clear channel prior to transmission. If the channel is busy it will backoff
//! for a random period, in time units of EASYLINK_CCA_BACKOFF_TIMEUNITS, before
//! reassessing. It does this a certain number
//! (EASYLINK_MAX_CCA_BACKOFF_WINDOW - EASYLINK_MIN_CCA_BACKOFF_WINDOW)
//! of times before quitting unsuccessfully and running to the callback.
//! If the Tx is successfully scheduled then the callback will be called once
//! the Tx is complete.
//!
//! \param txPacket The descriptor for the packet to be Tx'ed.
//! \param cb       The tx done function pointer.
//!
//! \return ::EasyLink_Status
//
//*****************************************************************************
extern EasyLink_Status EasyLink_transmitCcaAsync(EasyLink_TxPacket *txPacket,
        EasyLink_TxDoneCb cb);

你在哪里使用的，是否已经发送了数据

0 lin shi chang 3 年多前回复 Kevin Qiu1

Genius 3170 points

我看了这里的说明，不是太明白。我在rfEasyLinkEchoTx中的while(1)里使用的。
while(1)
{
send_pend();
Data.Crc16 = crc16((uint8_t *)&Data, sizeof(Data_Req) - 2);
memcpy(txPacket.payload, &Data, sizeof(Data_Req));
txPacket.len = sizeof(Data_Req); //18
txPacket.dstAddr[0] = Add;
txPacket.absTime = 0;

EasyLink_transmitCcaAsync(&txPacket, echoTxDoneCb);
Semaphore_pend(echoDoneSem, BIOS_WAIT_FOREVER);
}

应该是发送了，我设置2S发一次。50米前数据发送正常，信号强度不错。过了50米突然就收不到数据了。然后我又走回去，又收到了。

低于 1GHz

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RFEasyLinkEcho例程中关于CCA的相关问题