How to control the RS485 data transceiver direction

Zhai Yihua

Other Parts Discussed in Thread: CC2530

Dear friends,

We now use ZStack-CC2530-2.3.0-1.4.0, and need CC2530 send and receive data through RS485. if we set the data direction as CC2530 ->RS485 and don't change it, the data send is right. and if we set the direction is RS485 ->CC2530 and don't change it, the data receive also right.

But, when CC2530 need send data to RS485, we set the disrection (CC2530 ->RS485) befor HalUARTWrite(HAL_UART_PORT_0, pData, len); and set the contrary direction (RS485 ->CC2530) when UART send out event == HAL_UART_TX_EMPTY. we do it, but the dara error is very higher.

Please help me. how to control the RS485 data transceiver direction

BestRegard.Yihua

over 14 years ago

0 Albert Xu over 14 years ago

Prodigy 15 points

hi,have you been succeed in this problem?i met the problem too.please contact me,or we could discuss about it!

0 Zhai Yihua over 14 years ago in reply to Albert Xu

Intellectual 300 points

Dear Albert，

We have not solve it till now, do you have some good method.

BestRegard.Yihua

0 yanming70088 over 14 years ago in reply to Zhai Yihua

Prodigy 90 points

将程序改为ISR模式，（dma模式，不好控制）

具体修改TX 中断处理函数，如下：

#if (HAL_UART_ISR == 1)
HAL_ISR_FUNCTION( halUart0TxIsr, UTX0_VECTOR )
#else
HAL_ISR_FUNCTION( halUart1TxIsr, UTX1_VECTOR )
#endif
#endif
{

if (isrCfg.txHead == isrCfg.txTail)
{
    IEN2 &= ~UTXxIE;
    isrCfg.txMT = 1;
    MicroWait(1500);
    U1CSR|=0x40;
    P1_5=0;

}
else
{
    U1CSR&=~0x40;
    P1_5=1;
    UTXxIF = 0;
    UxDBUF = isrCfg.txBuf[isrCfg.txHead++];

    if (isrCfg.txHead >= HAL_UART_ISR_TX_MAX)
    {
      isrCfg.txHead = 0;
    }
}
}

其中P1_5为控制引脚。
这样做后，可以正常通信！

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How to control the RS485 data transceiver direction