Question

我是BBB和C编程的新手。我写了这个程序来接口SPI UART ic SC16IS750。当我运行这个程序时，这是我的输出。

ubuntu@arm:~$ ./Hello
 0  0  0  0  0  0  0  0  0  255  255  255  0  � ubuntu@arm:~$

程序应该如何工作，我应该阅读97;这不会发生

这是代码。

请帮助!!

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//#include <NXCTRL.h>

#include <unistd.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>

const uint16_t FCR  = 16;
const uint16_t LCR = 24;
const uint16_t SPR  =56;
const uint16_t DLL  =0;
const uint16_t DLM = 8;
const uint16_t EFR = 16;

static int
__SPI_read (int nFD, uint16_t nAddr, uint16_t *pnD)
{
  int nStatus;
  struct spi_ioc_transfer xfer[2];
  char rchTXData[4];
  char rchRXData[4];
  int i;

  memset(xfer, 0, sizeof(xfer));

 // memcpy(rchTXData, &INSTREAD, sizeof(uint8_t));
  memcpy(rchTXData , &nAddr, sizeof(uint16_t));
  memcpy(rchTXData + 2, pnD, sizeof(uint16_t));

  xfer[0].tx_buf = (unsigned int)rchTXData;
  xfer[0].rx_buf = (unsigned int)rchRXData;
  xfer[0].len = 3;
  xfer[0].delay_usecs = 200;

  nStatus = ioctl(nFD, SPI_IOC_MESSAGE(1), xfer);

  if (nStatus < 0)
  {
    perror("SPI_IOC_MESSAGE");
    return -1;
  }

  for (i = 0 ; i <= 3 ; i++)
      printf (" %d " , rchRXData[i]);

      //*pnD = rchRXData[3];
  return 0;

}


static int
__SPI_write (int nFD, uint16_t nAddr, uint16_t nD)
{
  int nStatus;
  struct spi_ioc_transfer xfer[2];
  char rchTXData[4];
  char rchRXData[4];

  memset(xfer, 0, sizeof(xfer));

  //memcpy(rchTXData, &INSTWRITE, sizeof(uint8_t));
  memcpy(rchTXData, &nAddr, sizeof(uint8_t));
  memcpy(rchTXData + 1, &nD, sizeof(uint16_t));

  xfer[0].tx_buf = (unsigned int)rchTXData;
  xfer[0].rx_buf = (unsigned int)rchRXData;
  xfer[0].len = 2;
  xfer[0].delay_usecs = 200;

  nStatus = ioctl(nFD, SPI_IOC_MESSAGE(1), xfer);

  if (nStatus < 0)
  {
    perror("SPI_IOC_MESSAGE");
    return -1;
  }

  return 0;

}

void SPI_UART_Init(int nFD)
{
    int x = 0;
    char rd;
    x = __SPI_write (nFD , LCR , 128 );
    printf (" %d " , x);
    x = __SPI_write (nFD , DLL , 96 );
    printf (" %d " , x);
    x = __SPI_write (nFD , DLM , 0 );
    printf (" %d " , x);
    x = __SPI_write (nFD , LCR , 191 );
    printf (" %d " , x);
    x = __SPI_write (nFD , EFR , 16 );
    printf (" %d " , x);
    x = __SPI_write (nFD , LCR , 3 );
    printf (" %d " , x);
    x = __SPI_write (nFD , FCR , 6 );
    printf (" %d " , x);
    x = __SPI_write (nFD , FCR , 1 );
    printf (" %d " , x);
    x = __SPI_write (nFD , SPR , 97 );
    printf (" %d " , x);
    __SPI_read (nFD , SPR ,&rd );
    printf (" %c " , rd );

}

int main (void) {

  int nFD, i;
  uint8_t nLSB, nD ,rD;
  uint32_t nSpeed, nSPIMode;
  uint16_t nAddr;


  nFD = open("/dev/spidev1.0", O_RDWR);



  nLSB = 0;

  ioctl(nFD, SPI_IOC_WR_LSB_FIRST, &nLSB);

  nSpeed = 500000;

  ioctl(nFD, SPI_IOC_WR_MAX_SPEED_HZ, &nSpeed);

  nSPIMode = SPI_MODE_0;

  ioctl(nFD, SPI_IOC_WR_MODE, &nSPIMode);



  nAddr = 305;

  nD = -1;



  for (i = 0; i < 1; i++)

      {
          SPI_UART_Init(nFD);
         usleep(900);
      }




     //  NXCTRLSleep(5, 0);



  close(nFD);

return(1);
}

带有SC16IS750的Beaglebone Black（BBB）接口（SPI到UART）

0 个答案: