@@ -46,21 +46,21 @@ import tmp102 # temperature sensor

     ### SENSOR BUS ADDRESSES ###

-# Set bus addresses of sensors

+# Set bus addresses of sensors.

 _PWR_SENSOR_ADDR = 0X40

 _BAT_TMP_SENSOR_ADDR = 0x48

 _AMB_TMP_SENSOR_ADDR = 0x4B

-# Set bus selector

+# Set bus selector.

 _BUS_SEL = 1

     ### FILE AND FOLDER LOCATIONS ###

 _USER = os.environ['USER']

-# folder for containing dynamic data objects

+# folder to contain dynamic data objects

 _DOCROOT_PATH = "/home/%s/public_html/power/" % _USER

-# folder for charts and output data file

+# folder to contain charts and output data file

 _CHARTS_DIRECTORY = _DOCROOT_PATH + "dynamic/"

-# location of data output file

+# location of JSON output data file

 _OUTPUT_DATA_FILE = _DOCROOT_PATH + "dynamic/powerData.js"

 # database that stores node data

 _RRD_FILE = "/home/%s/database/powerData.rrd" % _USER

@@ -82,13 +82,12 @@ _AVERAGE_LINE_COLOR = '#006600'

    ### GLOBAL VARIABLES ###

-# turn on or off of verbose debugging information

+# debug output options

 debugOption = False

 verboseDebug = False

-

 # frequency of data requests to sensors

 dataRequestInterval = _DEFAULT_DATA_REQUEST_INTERVAL

-# chart update interval

+# how often charts get updated

 chartUpdateInterval = _CHART_UPDATE_INTERVAL

 # last node request time

 lastDataPointTime = -1

@@ -127,9 +126,9 @@ def getEpochSeconds(sTime):

 ## end def

 def terminateAgentProcess(signal, frame):

-    """Send a message to log when the agent process gets killed

+    """Send a message to the log when the agent process gets killed

        by the operating system.  Inform downstream clients

-       by removing input and output data files.

+       by removing output data files.

        Parameters:

            signal, frame - dummy parameters

        Returns: nothing

@@ -145,10 +144,11 @@ def terminateAgentProcess(signal, frame):

   ###  PUBLIC METHODS  ###

 def getSensorData(dData):

-    """Poll sensors for data.

-       Parameters: none

-       Returns: a string containing the node signal data if successful,

-                or None if not successful

+    """Poll sensors for data. Store the data in a dictionary object for

+       use by other subroutines.  The dictionary object passed in should

+       an empty dictionary, i.e., dData = { }.

+       Parameters: dData - a dictionary object to contain the sensor data

+       Returns: True if successful, False otherwise

     """

     try:

         dData["time"] = getTimeStamp()

@@ -199,10 +199,10 @@ def updateDatabase(dData):

 def writeOutputDataFile(dData):

     """Write node data items to the output data file, formatted as 

-       a Javascript file.  This file may then be accessed and used by

-       by downstream clients, for instance, in HTML documents.

+       a Javascript file.  This file may then be requested and used by

+       by downstream clients, for instance, an HTML document.

        Parameters:

-           sData - a string object containing the data to be written

+           dData - a dictionary containing the data to be written

                    to the output data file

        Returns: True if successful, False otherwise

     """

@@ -238,8 +238,8 @@ def writeOutputDataFile(dData):

 ## end def

 def createGraph(fileName, dataItem, gLabel, gTitle, gStart,

-                lower, upper, trendLine, scaleFactor=1, autoScale=True, 

-                alertLine=""):

+                lower=0, upper=0, trendLine=0, scaleFactor=1,

+                autoScale=True, alertLine=""):

     """Uses rrdtool to create a graph of specified node data item.

        Parameters:

            fileName - name of file containing the graph

@@ -384,10 +384,11 @@ def getCLarguments():

     """Get command line arguments.  There are three possible arguments

           -d turns on debug mode

           -v turns on verbose debug mode

-          -t sets the sensor query interval

+          -p sets the sensor query period

+          -c sets the chart update period

        Returns: nothing

     """

-    global debugOption, verboseDebug, dataRequestInterval

+    global debugOption, verboseDebug, dataRequestInterval, chartUpdateInterval

     index = 1

     while index < len(sys.argv):

@@ -400,12 +401,20 @@ def getCLarguments():

             try:

                 dataRequestInterval = abs(int(sys.argv[index + 1]))

             except:

-                print "invalid polling period"

+                print "invalid sensor query period"

+                exit(-1)

+            index += 1

+        elif sys.argv[index] == '-c':

+            try:

+                chartUpdateInterval = abs(int(sys.argv[index + 1]))

+            except:

+                print "invalid chart update period"

                 exit(-1)

             index += 1

         else:

             cmd_name = sys.argv[0].split('/')

-            print "Usage: %s [-d] [-v] [-p seconds]" % cmd_name[-1]

+            print "Usage: %s [-d | v] [-p seconds] [-c seconds]" \

+                  % cmd_name[-1]

             exit(-1)

         index += 1

 ##end def