Add logic to limit the number of samples

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3996 42af7a65-404d-4744-a932-0658087f49c3

configs/sim/touchscreen/defconfig

@@ -551,10 +551,16 @@ CONFIG_EXAMPLES_MOUNT_DEVNAME="/dev/ram0"
 # CONFIG_EXAMPLES_TOUCHSCREEN_DEVPATH - The path to the touchscreen
 #   device.  This must be consistent with CONFIG_EXAMPLES_TOUCHSCREEN_MINOR.
 #   Default: "/dev/input0"
+# CONFIG_EXAMPLES_TOUCHSCREEN_NSAMPLES - If CONFIG_EXAMPLES_TOUCHSCREEN_BUILTIN
+#   is defined, then the number of samples is provided on the command line
+#   and this value is ignored.  Otherwise, this number of samples is
+#   collected and the program terminates.  Default:  Samples are collected
+#   indefinitely.
 #
 CONFIG_EXAMPLES_TOUCHSCREEN_BUILTIN=n
 CONFIG_EXAMPLES_TOUCHSCREEN_MINOR=0
 CONFIG_EXAMPLES_TOUCHSCREEN_DEVPATH="/dev/input0"
+CONFIG_EXAMPLES_TOUCHSCREEN_NSAMPLES=25
 
 #
 # Additional examples/touchscreen needed only for the simulated target