CDC ACM fixes

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3981 42af7a65-404d-4744-a932-0658087f49c3

examples/README.txt

@@ -975,6 +975,22 @@ examples/usbterm
   the local target serial console are received and forwarded to the
   remote host via USB serial.
 
+  Usage:
+    - Build the example and load into the target FLASH
+    - Connect on  terminal to the target RS-232 connect and configure
+      for 115200 8N1.  For example, suppose this Tera Term on a Windows
+      box.
+    - Power up the target board
+    - Connect the USB to a Linux box.  Use the Linux dmesg command to
+      assure that the connect was successful.  The USB CDC ACM device
+      should appear as /dev/ttyACM0
+    - On the Linux box, open minicom with tty=/dev/ttyACM0.
+      Configure minicom so that (1) local characters are echoed and (2)
+      so that no CR is required.
+    - Now what you type on the target Tera Term window should echo on
+      the Linux  minicom window and, conversely, what you type on the
+      minicom winow should be echo in the target Tera Term window.
+
   Configuration options:
 
   CONFIG_EXAMPLES_UBSTERM_BUILTIN - Build the usbterm example as an NSH

examples/usbterm/usbterm_main.c

@@ -134,9 +134,13 @@ FAR void *usbterm_listener(FAR void *parameter)
 
       if (fgets(g_usbterm.inbuffer, CONFIG_EXAMPLES_USBTERM_BUFLEN, g_usbterm.instream))
         {
-          /* Send the line of input via USB */
+          /* Echo the line on the local stdout */
 
-          fputs(g_usbterm.outbuffer, stdout);
+          fputs(g_usbterm.inbuffer, stdout);
+
+          /* Display the prompt string on stdout */
+
+          fputs("usbterm> ", stdout);
           fflush(stdout);
         }
 
@@ -235,14 +239,14 @@ int MAIN_NAME(int argc, char *argv[])
 
       dumptrace();
     }
-  while (g_usbterm.outstream < 0);
+  while (g_usbterm.outstream == NULL);
 
   /* Open the USB serial device for reading.  Since we are already connected, this
    * should not fail.
    */
 
   g_usbterm.instream = fopen("/dev/ttyUSB0", "r");
-  if (g_usbterm.instream < 0)
+  if (g_usbterm.instream == NULL)
     {
       message(MAIN_STRING "ERROR: Failed to open /dev/ttyUSB0 for reading: %d\n", errno);
       goto errout_with_outstream;
@@ -286,6 +290,10 @@ int MAIN_NAME(int argc, char *argv[])
           /* Send the line of input via USB */
 
           fputs(g_usbterm.outbuffer, g_usbterm.outstream);
+
+          /* Display the prompt string on the remote USB serial connection */
+
+          fputs("usbterm> ", g_usbterm.outstream);
           fflush(g_usbterm.outstream);
         }