#!/usr/bin/python2 -u
# The -u option above turns off block buffering of python output. This
# assures that each error message gets individually printed to the log file.
#
# Module: nodepowerAgent.py
#
# Description: This module acts as an agent between the mesh network and
# node power and enviromental sensors. The agent periodically polls the
# sensors and processes the data returned from the sensors, including
# - conversion of data items
# - update a round robin (rrdtool) database with the sensor data
# - periodically generate graphic charts for display in html documents
# - write the processed node status to a JSON file for use by html
# documents
#
# Copyright 2021 Jeff Owrey
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see http://www.gnu.org/license.
#
# Revision History
# * v10 released 01 June 2021 by J L Owrey; first release
#
#2345678901234567890123456789012345678901234567890123456789012345678901234567890
# Import required python libraries.
import os
import sys
import signal
import subprocess
import multiprocessing
import time
# Import sensor libraries.
import ina260 # power sensor
import tmp102 # temperature sensor
### SENSOR BUS ADDRESSES ###
# Set bus addresses of sensors
_PWR_SENSOR_ADDR = 0X40
_BAT_TMP_SENSOR_ADDR = 0x48
_AMB_TMP_SENSOR_ADDR = 0x4B
# Set bus selector
_BUS_SEL = 1
### FILE AND FOLDER LOCATIONS ###
_USER = os.environ['USER']
# folder for containing dynamic data objects
_DOCROOT_PATH = "/home/%s/public_html/power/" % _USER
# folder for charts and output data file
_CHARTS_DIRECTORY = _DOCROOT_PATH + "dynamic/"
# location of data output file
_OUTPUT_DATA_FILE = _DOCROOT_PATH + "dynamic/powerData.js"
# database that stores node data
_RRD_FILE = "/home/%s/database/powerData.rrd" % _USER
### GLOBAL CONSTANTS ###
# rrdtool database update interval in seconds
_DATABASE_UPDATE_INTERVAL = 30
# sensor data request interval in seconds
_DEFAULT_DATA_REQUEST_INTERVAL = 2
# chart update interval in seconds
_CHART_UPDATE_INTERVAL = 600
# standard chart width in pixels
_CHART_WIDTH = 600
# standard chart height in pixels
_CHART_HEIGHT = 150
### GLOBAL VARIABLES ###
# turn on or off of verbose debugging information
debugOption = False
verboseDebug = False
# frequency of data requests to sensors
dataRequestInterval = _DEFAULT_DATA_REQUEST_INTERVAL
# chart update interval
chartUpdateInterval = _CHART_UPDATE_INTERVAL
# last node request time
lastDataPointTime = -1
# Define each sensor. This also initialzes each sensor.
pwr = ina260.ina260(_PWR_SENSOR_ADDR, _BUS_SEL)
btmp = tmp102.tmp102(_BAT_TMP_SENSOR_ADDR, _BUS_SEL)
atmp = tmp102.tmp102(_AMB_TMP_SENSOR_ADDR, _BUS_SEL)
### PRIVATE METHODS ###
def getTimeStamp():
"""
Set the error message time stamp to the local system time.
Parameters: none
Returns: string containing the time stamp
"""
return time.strftime( "%m/%d/%Y %T", time.localtime() )
##end def
def getEpochSeconds(sTime):
"""Convert the time stamp supplied in the weather data string
to seconds since 1/1/1970 00:00:00.
Parameters:
sTime - the time stamp to be converted must be formatted
as %m/%d/%Y %H:%M:%S
Returns: epoch seconds
"""
try:
t_sTime = time.strptime(sTime, '%m/%d/%Y %H:%M:%S')
except Exception, exError:
print '%s getEpochSeconds: %s' % (getTimeStamp(), exError)
return None
tSeconds = int(time.mktime(t_sTime))
return tSeconds
##end def
def terminateAgentProcess(signal, frame):
"""Send a message to log when the agent process gets killed
by the operating system. Inform downstream clients
by removing input and output data files.
Parameters:
signal, frame - dummy parameters
Returns: nothing
"""
# Inform downstream clients by removing output data file.
if os.path.exists(_OUTPUT_DATA_FILE):
os.remove(_OUTPUT_DATA_FILE)
print '%s terminating npw agent process' % \
(getTimeStamp())
sys.exit(0)
##end def
### 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
"""
try:
dData["time"] = getTimeStamp()
dData["current"] = pwr.getCurrent()
dData["voltage"] = pwr.getVoltage()
dData["power"] = pwr.getPower()
dData["battemp"] = btmp.getTempC()
dData["ambtemp"] = atmp.getTempC()
except Exception, exError:
print "%s sensor error: %s" % (getTimeStamp(), exError)
return False
return True
##end def
def updateDatabase(dData):
"""
Update the rrdtool database by executing an rrdtool system command.
Format the command using the data extracted from the sensors.
Parameters: dData - dictionary object containing data items to be
written to the rr database file
Returns: True if successful, False otherwise
"""
epochTime = getEpochSeconds(dData['time'])
# Format the rrdtool update command.
strFmt = "rrdtool update %s %s:%s:%s:%s:%s:%s"
strCmd = strFmt % (_RRD_FILE, epochTime, dData['current'], \
dData['voltage'], dData['power'], dData['battemp'], \
dData['ambtemp'])
if debugOption:
print "%s" % strCmd # DEBUG
# Run the command as a subprocess.
try:
subprocess.check_output(strCmd, shell=True, \
stderr=subprocess.STDOUT)
except subprocess.CalledProcessError, exError:
print "%s: rrdtool update failed: %s" % \
(getTimeStamp(), exError.output)
return False
return True
##end def
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.
Parameters:
sData - a string object containing the data to be written
to the output data file
Returns: True if successful, False otherwise
"""
# Write a JSON formatted file for use by html clients. The following
# data items are sent to the client file.
# * The last database update date and time
# * The data request interval
# * The sensor values
# Create a JSON formatted string from the sensor data.
sData = "[{\"period\":\"%s\", " % \
(chartUpdateInterval)
for key in dData:
sData += '\"%s\":\"%s\", ' % (key, dData[key])
sData = sData[:-2] + '}]\n'
# Write the JSON formatted data to the output data file.
try:
fc = open(_OUTPUT_DATA_FILE, "w")
fc.write(sData)
fc.close()
except Exception, exError:
print "%s write output file failed: %s" % \
(getTimeStamp(), exError)
return False
if verboseDebug:
print sData[:-1]
if debugOption:
print "writing output data file: %d bytes" % len(sData)
return True
## end def
def createGraph(fileName, dataItem, gLabel, gTitle, gStart,
lower, upper, addTrend, autoScale):
"""Uses rrdtool to create a graph of specified node data item.
Parameters:
fileName - name of file containing the graph
dataItem - data item to be graphed
gLabel - string containing a graph label for the data item
gTitle - string containing a title for the graph
gStart - beginning time of the graphed data
lower - lower bound for graph ordinate #NOT USED
upper - upper bound for graph ordinate #NOT USED
addTrend - 0, show only graph data
1, show only a trend line
2, show a trend line and the graph data
autoScale - if True, then use vertical axis auto scaling
(lower and upper parameters are ignored), otherwise use
lower and upper parameters to set vertical axis scale
Returns: True if successful, False otherwise
"""
gPath = _CHARTS_DIRECTORY + fileName + ".png"
trendWindow = { 'end-1day': 7200,
'end-4weeks': 172800,
'end-12months': 604800 }
# Format the rrdtool graph command.
# Set chart start time, height, and width.
strCmd = "rrdtool graph %s -a PNG -s %s -e now -w %s -h %s " \
% (gPath, gStart, _CHART_WIDTH, _CHART_HEIGHT)
# Set the range and scaling of the chart y-axis.
if lower < upper:
strCmd += "-l %s -u %s -r " % (lower, upper)
elif autoScale:
strCmd += "-A "
strCmd += "-Y "
# Set the chart ordinate label and chart title.
strCmd += "-v %s -t %s " % (gLabel, gTitle)
# Show the data, or a moving average trend line over
# the data, or both.
strCmd += "DEF:dSeries=%s:%s:LAST " % (_RRD_FILE, dataItem)
if addTrend == 0:
strCmd += "LINE1:dSeries#0400ff "
elif addTrend == 1:
strCmd += "CDEF:smoothed=dSeries,%s,TREND LINE3:smoothed#ff0000 " \
% trendWindow[gStart]
elif addTrend == 2:
strCmd += "LINE1:dSeries#0400ff "
strCmd += "CDEF:smoothed=dSeries,%s,TREND LINE3:smoothed#ff0000 " \
% trendWindow[gStart]
if verboseDebug:
print "%s" % strCmd # DEBUG
# Run the formatted rrdtool command as a subprocess.
try:
result = subprocess.check_output(strCmd, \
stderr=subprocess.STDOUT, \
shell=True)
except subprocess.CalledProcessError, exError:
print "rrdtool graph failed: %s" % (exError.output)
return False
if debugOption:
print "rrdtool graph: %s\n" % result,
return True
##end def
def generateGraphs():
"""Generate graphs for display in html documents.
Parameters: none
Returns: nothing
"""
autoScale = False
# 24 hour stock charts
createGraph('24hr_current', 'CUR', 'mA',
'Current\ -\ Last\ 24\ Hours', 'end-1day', 0, 0, 2, autoScale)
createGraph('24hr_voltage', 'VOLT', 'V',
'Voltage\ -\ Last\ 24\ Hours', 'end-1day', 0, 0, 2, autoScale)
createGraph('24hr_power', 'PWR', 'mW',
'Power\ -\ Last\ 24\ Hours', 'end-1day', 0, 0, 2, autoScale)
createGraph('24hr_battemp', 'BTMP', 'deg\ C',
'Battery\ Temperature\ -\ Last\ 24\ Hours', 'end-1day', \
0, 0, 2, autoScale)
createGraph('24hr_ambtemp', 'ATMP', 'deg\ C',
'Ambient\ Temperature\ -\ Last\ 24\ Hours', 'end-1day', \
0, 0, 2, autoScale)
# 4 week stock charts
createGraph('4wk_current', 'CUR', 'mA',
'Current\ -\ Last\ 4\ Weeks', 'end-4weeks', 0, 0, 2, autoScale)
createGraph('4wk_voltage', 'VOLT', 'V',
'Voltage\ -\ Last\ 4\ Weeks', 'end-4weeks', 0, 0, 2, autoScale)
createGraph('4wk_power', 'PWR', 'mW',
'Power\ -\ Last\ 4\ Weeks', 'end-4weeks', 0, 0, 2, autoScale)
createGraph('4wk_battemp', 'BTMP', 'deg\ C',
'Battery\ Temperature\ -\ Last\ 4\ Weeks', 'end-4weeks', \
0, 0, 2, autoScale)
createGraph('4wk_ambtemp', 'ATMP', 'deg\ C',
'Ambient\ Temperature\ -\ Last\ 4\ Weeks', 'end-4weeks', \
0, 0, 2, autoScale)
# 12 month stock charts
createGraph('12m_current', 'CUR', 'mA',
'Current\ -\ Past\ Year', 'end-12months', 0, 0, 2, autoScale)
createGraph('12m_voltage', 'VOLT', 'V',
'Voltage\ -\ Past\ Year', 'end-12months', 0, 0, 2, autoScale)
createGraph('12m_power', 'PWR', 'mW',
'Power\ -\ Past\ Year', 'end-12months', 0, 0, 2, autoScale)
createGraph('12m_battemp', 'BTMP', 'deg\ C',
'Battery\ Temperature\ -\ Past\ Year', 'end-12months', \
0, 0, 2, autoScale)
createGraph('12m_ambtemp', 'ATMP', 'deg\ C',
'Ambient\ Temperature\ -\ Past\ Year', 'end-12months', \
0, 0, 2, autoScale)
##end def
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
Returns: nothing
"""
global debugOption, verboseDebug, dataRequestInterval
index = 1
while index < len(sys.argv):
if sys.argv[index] == '-d':
debugOption = True
elif sys.argv[index] == '-v':
debugOption = True
verboseDebug = True
elif sys.argv[index] == '-p':
try:
dataRequestInterval = abs(int(sys.argv[index + 1]))
except:
print "invalid polling period"
exit(-1)
index += 1
else:
cmd_name = sys.argv[0].split('/')
print "Usage: %s [-d] [-v] [-p seconds]" % cmd_name[-1]
exit(-1)
index += 1
##end def
def main():
"""Handles timing of events and acts as executive routine managing
all other functions.
Parameters: none
Returns: nothing
"""
global dataRequestInterval
signal.signal(signal.SIGTERM, terminateAgentProcess)
print '%s starting up node power agent process' % \
(getTimeStamp())
# last time output JSON file updated
lastDataRequestTime = -1
# last time charts generated
lastChartUpdateTime = - 1
# last time the rrdtool database updated
lastDatabaseUpdateTime = -1
## Get command line arguments.
getCLarguments()
## Exit with error if rrdtool database does not exist.
if not os.path.exists(_RRD_FILE):
print 'rrdtool database does not exist\n' \
'use createArednsigRrd script to ' \
'create rrdtool database\n'
exit(1)
## main loop
while True:
currentTime = time.time() # get current time in seconds
# Every web update interval request data from the aredn
# node and process the received data.
if currentTime - lastDataRequestTime > dataRequestInterval:
lastDataRequestTime = currentTime
dData = {}
result = True
# Get the data from the sensors.
result =getSensorData(dData)
# If get data successful, write data to data files.
if result:
result = writeOutputDataFile(dData)
# At the rrdtool database update interval, update the database.
if currentTime - lastDatabaseUpdateTime > \
_DATABASE_UPDATE_INTERVAL:
lastDatabaseUpdateTime = currentTime
## Update the round robin database with the parsed data.
if result:
updateDatabase(dData)
# At the chart generation interval, generate charts.
if currentTime - lastChartUpdateTime > chartUpdateInterval:
lastChartUpdateTime = currentTime
p = multiprocessing.Process(target=generateGraphs, args=())
p.start()
# Relinquish processing back to the operating system until
# the next update interval.
elapsedTime = time.time() - currentTime
if debugOption:
if result:
print "%s update successful:" % getTimeStamp(),
else:
print "%s update failed:" % getTimeStamp(),
print "%6f seconds processing time\n" % elapsedTime
remainingTime = dataRequestInterval - elapsedTime
if remainingTime > 0.0:
time.sleep(remainingTime)
## end while
return
## end def
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
print '\n',
terminateAgentProcess('KeyboardInterrupt','Module')