apps/examples/flowc: Add a delay between received packets in order to force input flow control.

examples/flowc/Kconfig

@@ -102,6 +102,10 @@ config EXAMPLES_FLOWC_RECEIVER_BUFSIZE
 	int "Receiver buffer size"
 	default 64
 
+config EXAMPLES_FLOWC_RECEIVER_DELAY
+	int "Receiver read delay (msec)"
+	default 100
+
 config EXAMPLES_FLOWC_RECEVER_DEVNAME
 	string "Default TTY device for receiver"
 	default "/dev/ttyACM0"

examples/flowc/flowc_receiver.c

@@ -191,6 +191,12 @@ int flowc_receiver(int argc, char **argv)
           close(fd);
           return 1;
         }
+
+#ifdef CONFIG_EXAMPLES_FLOWC_RECEIVER_DELAY
+      /* Delay to force flow control */
+
+      usleep(1000 * CONFIG_EXAMPLES_FLOWC_RECEIVER_DELAY);
+#endif
     }
 
   close(fd);