airpi.py

#This file takes in inputs from a variety of sensor files, and outputs information to a variety of services
import sys
sys.dont_write_bytecode = True

import RPi.GPIO as GPIO
import ConfigParser
import time
import inspect
import os
from sys import exit
from sensors import sensor
from outputs import output

def get_subclasses(mod,cls):
	for name, obj in inspect.getmembers(mod):
		if hasattr(obj, "__bases__") and cls in obj.__bases__:
			return obj


if not os.path.isfile('sensors.cfg'):
	print "Unable to access config file: sensors.cfg"
	exit(1)

sensorConfig = ConfigParser.SafeConfigParser()
sensorConfig.read('sensors.cfg')

sensorNames = sensorConfig.sections()

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM) #Use BCM GPIO numbers.

sensorPlugins = []
for i in sensorNames:
	try:	
		try:
			filename = sensorConfig.get(i,"filename")
		except Exception:
			print("Error: no filename config option found for sensor plugin " + i)
			raise
		try:
			enabled = sensorConfig.getboolean(i,"enabled")
		except Exception:
			enabled = True

		#if enabled, load the plugin
		if enabled:
			try:
				mod = __import__('sensors.'+filename,fromlist=['a']) #Why does this work?
			except Exception:
				print("Error: could not import sensor module " + filename)
				raise

			try:	
				sensorClass = get_subclasses(mod,sensor.Sensor)
				if sensorClass == None:
					raise AttributeError
			except Exception:
				print("Error: could not find a subclass of sensor.Sensor in module " + filename)
				raise

			try:	
				reqd = sensorClass.requiredData
			except Exception:
				reqd =  []
			try:
				opt = sensorClass.optionalData
			except Exception:
				opt = []

			pluginData = {}

			class MissingField(Exception): pass
						
			for requiredField in reqd:
				if sensorConfig.has_option(i,requiredField):
					pluginData[requiredField]=sensorConfig.get(i,requiredField)
				else:
					print "Error: Missing required field '" + requiredField + "' for sensor plugin " + i
					raise MissingField
			for optionalField in opt:
				if sensorConfig.has_option(i,optionalField):
					pluginData[optionalField]=sensorConfig.get(i,optionalField)
			instClass = sensorClass(pluginData)
			sensorPlugins.append(instClass)
			print ("Success: Loaded sensor plugin " + i)
	except Exception as e: #add specific exception for missing module
		print("Error: Did not import sensor plugin " + i )
		raise e


if not os.path.isfile("outputs.cfg"):
	print "Unable to access config file: outputs.cfg"

outputConfig = ConfigParser.SafeConfigParser()
outputConfig.read("outputs.cfg")

outputNames = outputConfig.sections()

outputPlugins = []

for i in outputNames:
	try:	
		try:
			filename = outputConfig.get(i,"filename")
		except Exception:
			print("Error: no filename config option found for output plugin " + i)
			raise
		try:
			enabled = outputConfig.getboolean(i,"enabled")
		except Exception:
			enabled = True

		#if enabled, load the plugin
		if enabled:
			try:
				mod = __import__('outputs.'+filename,fromlist=['a']) #Why does this work?
			except Exception:
				print("Error: could not import output module " + filename)
				raise

			try:	
				outputClass = get_subclasses(mod,output.Output)
				if outputClass == None:
					raise AttributeError
			except Exception:
				print("Error: could not find a subclass of output.Output in module " + filename)
				raise
			try:	
				reqd = outputClass.requiredData
			except Exception:
				reqd =  []
			try:
				opt = outputClass.optionalData
			except Exception:
				opt = []
			
			if outputConfig.has_option(i,"async"):
				async = outputConfig.getbool(i,"async")
			else:
				async = False
			
			pluginData = {}

			class MissingField(Exception): pass
						
			for requiredField in reqd:
				if outputConfig.has_option(i,requiredField):
					pluginData[requiredField]=outputConfig.get(i,requiredField)
				else:
					print "Error: Missing required field '" + requiredField + "' for output plugin " + i
					raise MissingField
			for optionalField in opt:
				if outputConfig.has_option(i,optionalField):
					pluginData[optionalField]=outputConfig.get(i,optionalField)
			instClass = outputClass(pluginData)
			instClass.async = async
			outputPlugins.append(instClass)
			print ("Success: Loaded output plugin " + i)
	except Exception as e: #add specific exception for missing module
		print("Error: Did not import output plugin " + i )
		raise e

if not os.path.isfile("settings.cfg"):
	print "Unable to access config file: settings.cfg"

mainConfig = ConfigParser.SafeConfigParser()
mainConfig.read("settings.cfg")

lastUpdated = 0
delayTime = mainConfig.getfloat("Main","uploadDelay")
redPin = mainConfig.getint("Main","redPin")
greenPin = mainConfig.getint("Main","greenPin")
GPIO.setup(redPin,GPIO.OUT,initial=GPIO.LOW)
GPIO.setup(greenPin,GPIO.OUT,initial=GPIO.LOW)
while True:
	curTime = time.time()
	if (curTime-lastUpdated)>delayTime:
		lastUpdated = curTime
		data = []
		#Collect the data from each sensor
		for i in sensorPlugins:
			dataDict = {}
			val = i.getVal()
			if val==None: #this means it has no data to upload.
				continue
			dataDict["value"] = i.getVal()
			dataDict["unit"] = i.valUnit
			dataDict["symbol"] = i.valSymbol
			dataDict["name"] = i.valName
			dataDict["sensor"] = i.sensorName
			data.append(dataDict)
		working = True
		for i in outputPlugins:
			working = working and i.outputData(data)
		if working:
			print "Uploaded successfully"
			GPIO.output(greenPin,GPIO.HIGH)
		else:
			print "Failed to upload"
			GPIO.output(redPin,GPIO.HIGH)
		time.sleep(1)
		GPIO.output(greenPin,GPIO.LOW)
		GPIO.output(redPin,GPIO.LOW)