serial port example

main.cpp

@@ -0,0 +1,100 @@
+/**
+ * Serial port example.
+ * Compile with: g++ main.cpp -lpthread -o main
+ * 
+ * Cymait http://cymait.com
+ **/
+
+#include <iostream>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <termios.h>
+
+#define BUFFER_SIZE 128
+#define BAUDRATE    B9600
+
+void usage(char* cmd) {
+    std::cerr << "usage: " << cmd << " slave|master [device, only in slave mode]" << std::endl;
+    exit(1);
+}
+
+void* reader_thread(void* pointer) {
+    int fd = (int)pointer;
+    char inputbyte;
+    while (read(fd, &inputbyte, 1) == 1) {
+        std::cout << inputbyte;
+        std::cout.flush();
+    }
+
+    return 0;
+}
+
+int main(int argc, char** argv) {
+    if (argc < 2) usage(argv[0]);
+
+    int fd = 0;
+    std::string mode = argv[1];
+
+    if (mode == "slave") {
+        if (argc < 3) usage(argv[1]);
+
+        fd = open(argv[2], O_RDWR);
+        if (fd == -1) {
+            std::cerr << "error opening file" << std::endl;
+            return -1;
+        }
+
+    }else if (mode=="master") {
+        fd = open("/dev/ptmx", O_RDWR | O_NOCTTY);
+        if (fd == -1) {
+            std::cerr << "error opening file" << std::endl;
+            return -1;
+        }
+
+        grantpt(fd);
+        unlockpt(fd);
+
+        char* pts_name = ptsname(fd);
+        std::cerr << "ptsname: " << pts_name << std::endl;
+    } else {
+        usage(argv[1]);
+    }
+
+    /* serial port parameters */
+    struct termios newtio;
+    memset(&newtio, 0, sizeof(newtio));
+    struct termios oldtio;
+    tcgetattr(fd, &oldtio);
+
+    newtio = oldtio;
+    newtio.c_cflag = BAUDRATE | CS8 | CLOCAL | CREAD;
+    newtio.c_iflag = 0;
+    newtio.c_oflag = 0;
+    newtio.c_lflag = 0;
+    newtio.c_cc[VMIN] = 1;
+    newtio.c_cc[VTIME] = 0;
+    tcflush(fd, TCIFLUSH);
+
+    cfsetispeed(&newtio, BAUDRATE);
+    cfsetospeed(&newtio, BAUDRATE);
+    tcsetattr(fd, TCSANOW, &newtio);
+
+    /* start reader thread */
+    pthread_t thread;
+    pthread_create(&thread, 0, reader_thread, (void*) fd);
+
+    /* read from stdin and send it to the serial port */
+    char c;
+    while (true) {
+        std::cin >> c;
+        write(fd, &c, 1);
+    }
+
+    close(fd);
+    return 0;
+}