RT1021使用RTS引脚控制RS485芯片收发使能

 

 

 

 

 

 

 

 

串口初始化完成后增加两行代码：

DEMO_LPUART->MODIR |= LPUART_MODIR_TXRTSE_MASK;
DEMO_LPUART->MODIR |= LPUART_MODIR_TXRTSPOL_MASK;

即可使用RTS引脚直接控制RS485收发器收发使能。

/*
 * Copyright 2017 NXP
 * All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#include "pin_mux.h"
#include "clock_config.h"
#include "board.h"
#include "fsl_lpuart.h"
#include "fsl_debug_console.h"
 
/*******************************************************************************
 * Definitions
 ******************************************************************************/
#define DEMO_LPUART          LPUART2
#define DEMO_LPUART_CLK_FREQ BOARD_DebugConsoleSrcFreq()
#define DELAY_TIME           100000U
#define TRANSFER_SIZE     256U    /*! Transfer dataSize */
#define TRANSFER_BAUDRATE 115200U /*! Transfer baudrate - 115200 */
 
/*******************************************************************************
 * Prototypes
 ******************************************************************************/
/* LPUART user callback */
void LPUART_UserCallback(LPUART_Type *base, lpuart_handle_t *handle, status_t status, void *userData);
 
/*******************************************************************************
 * Variables
 ******************************************************************************/
uint8_t transferRxData[TRANSFER_SIZE] = {0U};
uint8_t transferTxData[TRANSFER_SIZE] = {0U};
lpuart_handle_t g_lpuartHandle;
volatile bool isTransferCompleted = false;
 
/*******************************************************************************
 * Code
 ******************************************************************************/
/* LPUART user callback */
void LPUART_UserCallback(LPUART_Type *base, lpuart_handle_t *handle, status_t status, void *userData)
{
    if (kStatus_LPUART_TxIdle == status)
    {
        isTransferCompleted = true;
    }
}
/*!
 * @brief Main function
 */
int main(void)
{
    uint32_t i = 0U, errCount = 0U;
    status_t status = 0;
    lpuart_config_t config;
    lpuart_transfer_t sendXfer;
 
    BOARD_ConfigMPU();
    BOARD_InitBootPins();
    BOARD_InitBootClocks();
    BOARD_InitDebugConsole();
    PRINTF("This is LPUART hardware flow control example on one board.\r\n");
    PRINTF("This example will send data to itself and will use hardware flow control to avoid the overflow.\r\n");
    PRINTF("Please make sure you make the correct line connection. Basically, the connection is: \r\n");
    PRINTF("      LPUART_TX    --     LPUART_RX    \r\n");
    PRINTF("      LPUART_RTS   --     LPUART_CTS   \r\n");
    /*
     * config.baudRate_Bps = 115200U;
     * config.parityMode = kLPUART_ParityDisabled;
     * config.stopBitCount = kLPUART_OneStopBit;
     * config.txFifoWatermark = 0;
     * config.rxFifoWatermark = 0;
     * config.enableTx = false;
     * config.enableRx = false;
     */
    LPUART_GetDefaultConfig(&config);
    config.baudRate_Bps = BOARD_DEBUG_UART_BAUDRATE;
    config.enableTx     = true;
    config.enableRx     = true;
    //config.enableRxRTS  = true;
    //config.enableTxCTS  = true;
 
    LPUART_Init(DEMO_LPUART, &config, DEMO_LPUART_CLK_FREQ);
    DEMO_LPUART->MODIR |= LPUART_MODIR_TXRTSE_MASK;
    DEMO_LPUART->MODIR |= LPUART_MODIR_TXRTSPOL_MASK;
    LPUART_TransferCreateHandle(DEMO_LPUART, &g_lpuartHandle, LPUART_UserCallback, NULL);
    while(1){
        /* Set up the transfer data */
        for (i = 0U; i < TRANSFER_SIZE; i++)
        {
            transferTxData[i] = i % 256U;
            transferRxData[i] = 0U;
        }
 
        sendXfer.data     = (uint8_t *)transferTxData;
        sendXfer.dataSize = TRANSFER_SIZE;
        LPUART_TransferSendNonBlocking(DEMO_LPUART, &g_lpuartHandle, &sendXfer);
 
        /* Delay for some time to let the RTS pin dessart. */
        for (i = 0U; i < DELAY_TIME; i++)
        {
            __NOP();
        }
    }
 
 
 
    /* Set up the transfer data */
    for (i = 0U; i < TRANSFER_SIZE; i++)
    {
        transferTxData[i] = i % 256U;
        transferRxData[i] = 0U;
    }
 
    sendXfer.data     = (uint8_t *)transferTxData;
    sendXfer.dataSize = TRANSFER_SIZE;
    LPUART_TransferSendNonBlocking(DEMO_LPUART, &g_lpuartHandle, &sendXfer);
 
    /* Delay for some time to let the RTS pin dessart. */
    for (i = 0U; i < DELAY_TIME; i++)
    {
        __NOP();
    }
 
 
 
    status = LPUART_ReadBlocking(DEMO_LPUART, transferRxData, TRANSFER_SIZE);
    if (kStatus_Success != status)
    {
        PRINTF(" Error occurred when LPUART receiving data.\r\n");
    }
    /* Wait for the transmit complete. */
    while (!isTransferCompleted)
    {
    }
 
    for (i = 0U; i < TRANSFER_SIZE; i++)
    {
        if (transferTxData[i] != transferRxData[i])
        {
            errCount++;
        }
    }
    if (errCount)
    {
        PRINTF("Data not matched! Transfer error.\r\n");
    }
    else
    {
        PRINTF("Data matched! Transfer successfully.\r\n");
    }
 
    /* Deinit the LPUART. */
    LPUART_Deinit(DEMO_LPUART);
 
    while (1)
    {
    }
}