Verzögerung des LRF durch Löschen des Buffers vermeiden, Automatische...

Verzögerung des LRF durch Löschen des Buffers vermeiden, Automatische Erkennung des Ports (Issue #7910)
refs 7909

org.fortiss.af3.platform.raspberry/trunk/lib/inc/libuart.h

@@ -30,4 +30,6 @@ int uart_receive(char*, int, int);
 
 void uart_close();
 
+void uart_flush();
+
 #endif

org.fortiss.af3.platform.raspberry/trunk/lib/src/LaserRangeFinder.c

 
 #include "inc/LaserRangeFinder.h"
 
-// constants
-const char* LRF_DEVICE_NAME = "/dev/ttyACM0";
-
 // init, terminate
 void lrf_init() {
-    uart_setup(LRF_DEVICE_NAME);
+    char port[] = "/dev/????????";
+
+    FILE* fp = popen("dmesg | grep -A 3 \"Arduino Uno\"  | grep -o \"ttyACM.\" | tail -n 1","r");
+    fgets(port+5, sizeof(port)-6, fp);
+    printf("Port: %s\n", port);
+    pclose(fp);
+
+    uart_setup(port);
 }
 
 void lrf_term() {
@@ -27,6 +31,11 @@ GEN_TYPE_int lrf_read() {
 
     int i;
 
+    int d;
+
+    // free buffer
+    uart_flush();
+
     // looks like a blocking call and actually is but is always very fast
     // since it only has to read the queue
     while (1) {
@@ -36,10 +45,11 @@ GEN_TYPE_int lrf_read() {
             if (bytes[i] != 0xd && bytes[i] != 0xa) {
                 value[n++] = bytes[i];
             } else if (atoi(value) != 0) {
+                d = atoi(value);
                 for (i = n; i < 3; i++) {
                     value[i] = 0;
                 }
-                return atoi(value);
+                return d;
             }
         }
     }

org.fortiss.af3.platform.raspberry/trunk/lib/src/libuart.c

@@ -36,7 +36,9 @@ int uart_setup(const char *porta) {
     tty.c_cflag |= CREAD | CLOCAL;
 
     cfmakeraw(&tty);
-    tcflush(uart_filestream, TCIFLUSH);
+
+    uart_flush();
+
     if (tcsetattr(uart_filestream, TCSANOW, &tty) != 0) {
         fprintf(stderr, "[%s] Error from tcsetattr: %s\n", port, strerror(errno));
     }
@@ -123,3 +125,7 @@ int uart_receive(char *c, int bufLen, int printt) {
 void uart_close() {
     close(uart_filestream);
 }
+
+void uart_flush() {
+    tcflush(uart_filestream, TCIFLUSH);
+}