uart 操作
本帖最后由 seeing 于 2014-6-14 09:44 编辑請問 Cubian 的 uart 可以操作嗎？我修改了 /boot 中的 script.bin 後已經可以看到 ttyS1 的裝置，也寫了程式測試通訊的部份，不過似乎有問題，資料送出 55 01 12 00 00 00 02 6A，卻是收到 55 7F BB FF FF FB 2B 00，不曉得是哪裡設置有問題？
uart4
baudrate：9600, n, 8, 1
環境：uart4 直接接 pc 的 com1
uart_used = 1
uart_port = 4
uart_type = 2
uart_tx = port:PG10<4><1><default><default>
uart_rx = port:PG11<4><1><default><default>
cubian 程式如下：
#include <stdio.h> // standard input / output functions
#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 definitionss
#include <time.h> // time calls
int open_port(void)
{
int fd; // file description for the serial port
fd = open("/dev/ttyS1", O_RDWR | O_NOCTTY | O_NDELAY);
if(fd == -1) // if open is unsucessful
{
printf("open_port: Unable to open /dev/ttyS0. \n");
}
else
{
fcntl(fd, F_SETFL, 0);
printf("port is open.\n");
}
return(fd);
} //open_port
int configure_port(int fd) // configure the port
{
struct termios port_settings; // structure to store the port settings in
cfsetispeed(&port_settings, B9600); // set baud rates
cfsetospeed(&port_settings, B9600);
port_settings.c_cflag &= ~PARENB; // set no parity, stop bits, data bits
port_settings.c_cflag &= ~CSTOPB;
port_settings.c_cflag &= ~CSIZE;
port_settings.c_cflag |= CS8;
fcntl(fd, F_SETFL, FNDELAY);
tcsetattr(fd, TCSANOW, &port_settings); // apply the settings to the port
return(fd);
} //configure_port
int query_modem(int fd) // query modem with an AT command
{
char n;
fd_set rdfs;
struct timeval timeout;
// initialise the timeout structure
timeout.tv_sec = 10; // ten second timeout
timeout.tv_usec = 0;
//Create byte array
unsigned char send_bytes;
send_bytes = 0x55;
send_bytes = 0x01;
send_bytes = 0x12;
send_bytes = 0x00;
send_bytes = 0x00;
send_bytes = 0x00;
send_bytes = 0x02;
send_bytes = 0x6A;
write(fd, send_bytes, 8);//Send data
printf("Wrote the bytes. \n");
return 0;
} //query_modem
int main(void)
{
int fd = open_port();
configure_port(fd);
query_modem(fd);
return(0);
} //main
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