シリアルケーブルをiPhoneに接続するためにシリアルプログラミングを使用しています
私のコードは以下の通りです
#include <stdio.h> /* Standard input/output definitions */
#include <string.h> /* String function definitions */
#include <unistd.h> /* UNIX standard function definitions */
#include <fcntl.h> /* File control definitions */
#include <errno.h> /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */
static struct termios gOriginalTTYAttrs;
static int OpenSerialPort()
{
int fileDescriptor = -1;
int handshake;
struct termios options;
// Open the serial port read/write, with no controlling terminal, and don't wait for a connection.
// The O_NONBLOCK flag also causes subsequent I/O on the device to be non-blocking.
// See open(2) ("man 2 open") for details.
fileDescriptor = open("/dev/tty.iap", O_RDWR | O_NOCTTY | O_NONBLOCK);
if (fileDescriptor == -1)
{
printf("Error opening serial port %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Note that open() follows POSIX semantics: multiple open() calls to the same file will succeed
// unless the TIOCEXCL ioctl is issued. This will prevent additional opens except by root-owned
// processes.
// See tty(4) ("man 4 tty") and ioctl(2) ("man 2 ioctl") for details.
if (ioctl(fileDescriptor, TIOCEXCL) == -1)
{
printf("Error setting TIOCEXCL on %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Now that the device is open, clear the O_NONBLOCK flag so subsequent I/O will block.
// See fcntl(2) ("man 2 fcntl") for details.
if (fcntl(fileDescriptor, F_SETFL, 0) == -1)
{
printf("Error clearing O_NONBLOCK %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Get the current options and save them so we can restore the default settings later.
if (tcgetattr(fileDescriptor, &gOriginalTTYAttrs) == -1)
{
printf("Error getting tty attributes %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// The serial port attributes such as timeouts and baud rate are set by modifying the termios
// structure and then calling tcsetattr() to cause the changes to take effect. Note that the
// changes will not become effective without the tcsetattr() call.
// See tcsetattr(4) ("man 4 tcsetattr") for details.
options = gOriginalTTYAttrs;
// Print the current input and output baud rates.
// See tcsetattr(4) ("man 4 tcsetattr") for details.
printf("Current input baud rate is %d\n", (int) cfgetispeed(&options));
printf("Current output baud rate is %d\n", (int) cfgetospeed(&options));
// Set raw input (non-canonical) mode, with reads blocking until either a single character
// has been received or a one second timeout expires.
// See tcsetattr(4) ("man 4 tcsetattr") and termios(4) ("man 4 termios") for details.
cfmakeraw(&options);
options.c_cc[VMIN] = 1;
options.c_cc[VTIME] = 10;
// The baud rate, word length, and handshake options can be set as follows:
cfsetspeed(&options, B19200); // Set 19200 baud
options.c_cflag |= (CS8); // RTS flow control of input
printf("Input baud rate changed to %d\n", (int) cfgetispeed(&options));
printf("Output baud rate changed to %d\n", (int) cfgetospeed(&options));
// Cause the new options to take effect immediately.
if (tcsetattr(fileDescriptor, TCSANOW, &options) == -1)
{
printf("Error setting tty attributes %s - %s(%d).\n",
"/dev/tty.iap", strerror(errno), errno);
goto error;
}
// Success
return fileDescriptor;
// Failure "/dev/tty.iap"
error:
if (fileDescriptor != -1)
{
close(fileDescriptor);
}
return -1;
}
int main(int args, char *argv[])
{
int fd;
char somechar[8];
fd=OpenSerialPort(); // Open tty.iap with no hardware control, 8 bit, BLOCKING and at 19200 baud
if(fd>-1)
{
write(fd,"*",1); // Write handshaking message over serial
///////////////////////////////////////////////////////////////////////////////////////////////////
// After this, our device or our PC program should be strobing serial ground to gain access to the Iphone Serial Line
//////////////////////////////////////////////////////////////////////////////////////////////////
read(fd,&somechar[0],1); // Read 1 byte over serial. This will block (wait) untill the byte has been received
if(somechar[0]=='*') // Check if this byte is a "handshaking" message
{
printf("Serial connection established!\n"); // If it is, we have established a connection to the device and can freely read/write over serial!
while(1) // Do this forever or untill someone presses CTRL+C
{
read(fd,&somechar[0],1); // Read a character over serial!
putchar(somechar[0]); // Write the character to the Terminal!!
}
}
}
return 0;
}
しかし、ケーブルが接続されているかどうかを確認しようとすると、このようなエラーが1つ発生しました
シリアル ポート /dev/tty.iap を開く際のエラー - 操作は許可されていません (1)。
解決策を知っている人はいますか?私が間違った方法で進んでいる場合は、実際に私は iOS 開発の初心者なので、もっと混乱しています。
ありがとう