brewpi.py

# Copyright 2012 BrewPi/Elco Jacobs.
# This file is part of BrewPi.

# BrewPi 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.

# BrewPi 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 BrewPi.  If not, see <http://www.gnu.org/licenses/>.

from pprint import pprint
import serial
import time
from datetime import datetime
# import gviz_api
import socket
import sys
import os
import shutil
import urllib
import simplejson as json
from configobj import ConfigObj

#local imports
import temperatureProfile
import programArduino as programmer
import brewpiJson

# Temperature limit defines
# To prevent invalid settings temperatures should be between these limits
# Comment what you don't need, C or F

# Settings will be read from Arduino, initialize with same defaults as Arduino
# This is mainly to show what's expected. Will all be overwritten

# Control Settings
cs = {	'mode': 'b',
		'beerSetting': 20.0,
		'fridgeSetting': 20.0,
		'heatEstimator': 0.2,
		'coolEstimator': 5}
# Control Constants
cc = {	'tempFormat': 'C',
		'tempSettingMin': 4.0,
		'tempSettingMax': 30.0,
		'KpHeat': 10.000,
		'KpCool': 5.000,
		'Ki': 0.020,
		'KdCool': -10.000,
		'KdHeat': -5.000,
		'iMaxSlope': 0.05,
		'iMinSlope': -0.1,
		'iMaxError': 0.5,
		'idleRangeHigh': 0.500,
		'idleRangeLow': -0.500,
		'heatingTargetUpper': 0.199,
		'heatingTargetLower': -0.100,
		'coolingTargetUpper': 0.100,
		'coolingTargetLower': -0.199,
		'maxHeatTimeForEstimate': 600,
		'maxCoolTimeForEstimate': 1200}
# Control variables
cv = {	'beerDiff': 0,
		'fridgeDiff': 0,
		'diffIntegral': 0,
		'beerSlope': 0,
		'p': 0,
		'i': 0,
		'd': 0,
		'Kp': 0,
		'Kd': 0,
		'estimatedPeak': 0,
		'negPeakSetting': 0,
		'posPeakSetting': 0,
		'negPeak': 0,
		'posPeak': 0}

# global variables, will be initialized by startBeer()
config = ConfigObj('/home/brewpi/settings/config.cfg')
localJsonFileName = ""
localCsvFileName = ""
wwwJsonFileName = ""
wwwCsvFileName = ""
lastDay = ""
day = ""


# wwwSettings.json is a copy of some of the settings for the web server
def changeWwwSetting(settingName, value):
	wwwSettingsFile = open(config['wwwPath'] + 'wwwSettings.json', 'r+b')
	wwwSettings = json.load(wwwSettingsFile)
	wwwSettings[settingName] = value
	wwwSettingsFile.seek(0)
	wwwSettingsFile.write(json.dumps(wwwSettings))
	wwwSettingsFile.truncate()
	wwwSettingsFile.close()


def startBeer(beerName):
	global config
	global localJsonFileName
	global localCsvFileName
	global wwwJsonFileName
	global wwwCsvFileName
	global lastDay
	global day

	# create directory for the data if it does not exist
	dataPath = config['scriptPath'] + 'data/' + beerName + '/'
	wwwDataPath = config['wwwPath'] + 'data/' + beerName + '/'

	if not os.path.exists(dataPath):
		os.makedirs(dataPath)
		os.chmod(dataPath, 0775)  # give group all permissions
	if not os.path.exists(wwwDataPath):
		os.makedirs(wwwDataPath)
		os.chmod(wwwDataPath, 0775)  # sudgive group all permissions

	# Keep track of day and make new data tabe for each day
	# This limits data table size, which can grow very big otherwise
	day = time.strftime("%Y-%m-%d")
	lastDay = day
	# define a JSON file to store the data table
	jsonFileName = config['beerName'] + '-' + day
	#if a file for today already existed, add suffix
	if os.path.isfile(dataPath + jsonFileName + '.json'):
		i = 1
		while(os.path.isfile(
				dataPath + jsonFileName + '-' + str(i) + '.json')):
			i = i + 1
		jsonFileName = jsonFileName + '-' + str(i)
	localJsonFileName = dataPath + jsonFileName + '.json'
	brewpiJson.newEmptyFile(localJsonFileName)

	# Define a location on the webserver to copy the file to after it is written
	wwwJsonFileName = wwwDataPath + jsonFileName + '.json'

	# Define a CSV file to store the data as CSV (might be useful one day)
	localCsvFileName = (dataPath + config['beerName'] + '.csv')
	wwwCsvFileName = (wwwDataPath + config['beerName'] + '.csv')
	changeWwwSetting('beerName', beerName)


# open serial port
try:
	ser = serial.Serial(config['port'], 57600, timeout=1)
except serial.SerialException, e:
	print e
	exit()

print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
	"Notification: Script started for beer '" + config['beerName']) + "'"
# wait for 10 seconds to allow an Uno to reboot (in case an Uno is being used)
time.sleep(10)
# read settings from Arduino
ser.flush()
ser.write('s')
time.sleep(1)
while(1):  # read all lines on serial interface
	line = ser.readline()
	if(line):  # line available?
		if line[0] == 'S':
			try:
				cs = json.loads(line[2:])
			except json.decoder.JSONDecodeError, e:
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
					"JSON decode error: %s" % e)
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") + "Error: "
				"Cannot receive settings from Arduino, script will exit.")
				exit()
			break
	else:
		print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") + "Error: "
				"Cannot receive settings from Arduino, script will exit.")
		exit()

print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
						"Settings loaded: ")
pprint(cs, sys.stderr)

# read control constants from Arduino
ser.flush()
ser.write('c')
time.sleep(1)
while(1):  # read all lines on serial interface
	line = ser.readline()
	if(line):  # line available?
		if line[0] == 'C':
			try:
				cc = json.loads(line[2:])
			except json.decoder.JSONDecodeError, e:
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
					"JSON decode error: %s" % e)
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") + "Error: "
				"Cannot receive constants from Arduino, script will exit.")
				exit()
			break
	else:
		print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") + "Error: "
				"Cannot receive constants from Arduino, Script will exit.")
		exit()

print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
						"Constants loaded: ")
pprint(cc, sys.stderr)


#create a listening socket to communicate with PHP
if os.path.exists(config['scriptPath'] + '/BEERSOCKET'):
	# if socket already exists, remove it
	os.remove(config['scriptPath'] + '/BEERSOCKET')
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(config['scriptPath'] + '/BEERSOCKET')  # Bind BEERSOCKET
# set all permissions for socket
os.chmod(config['scriptPath'] + '/BEERSOCKET', 0777)
s.setblocking(1)  # set socket functions to be blocking
s.listen(5)  # Create a backlog queue for up to 5 connections
# blocking socket functions wait 'serialCheckInterval' seconds
s.settimeout(float(config['serialCheckInterval']))

# The arduino nano resets when linux connects to the serial port.
# Delay to give it time to restart.
# time.sleep(8)

prevDataTime = 0.0  # keep track of time between new data requests
prevTimeOut = time.time()

run = 1
lcdText = "Script starting up"

startBeer(config['beerName'])

while(run):
	# Check wheter it is a new day
	lastDay = day
	day = time.strftime("%Y-%m-%d")
	if lastDay != day:
		print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
			"Notification: New day, dropping data table and creating new JSON file.")
		jsonFileName = config['beerName'] + '/' + config['beerName'] + '-' + day
		localJsonFileName = config['scriptPath'] + 'data/' + jsonFileName + '.json'
		wwwJsonFileName = config['wwwPath'] + 'data/' + jsonFileName + '.json'
		# create new empty json file
		brewpiJson.newEmptyFile(localJsonFileName)

	# Wait for incoming socket connections.
	# When nothing is received, socket.timeout will be raised after
	# serialCheckInterval seconds. Serial receive will be done then.
	# When messages are expected on serial, the timeout is raised 'manually'
	try:
		conn, addr = s.accept()
		# blocking receive, times out in serialCheckInterval
		message = conn.recv(1024)
		if "=" in message:
			messageType, value = message.split("=", 1)
		else:
			messageType = message

		if messageType == "stopScript":  # exit instruction received. Stop script.
			run = 0
			# voluntary shutdown.
			# write a file to prevent the cron job from restarting the script
			dontrunfile = open(config['wwwPath'] + 'do_not_run_brewpi', "w")
			dontrunfile.write("1")
			dontrunfile.close()
			continue
		elif messageType == "ack":  # acknowledge request
			conn.send('ack')
		elif messageType == "getMode":  # echo cs['mode'] setting
			conn.send(cs['mode'])
		elif messageType == "getFridge":  # echo fridge temperature setting
			conn.send(str(cs['fridgeSetting']))
		elif messageType == "getBeer":  # echo fridge temperature setting
			conn.send(str(cs['beerSetting']))
		elif messageType == "setBeer":  # new constant beer temperature received
			newTemp = float(value)
			if(newTemp > cc['tempSettingMin'] and newTemp < cc['tempSettingMax']):
				cs['mode'] = 'b'
				# round to 2 dec, python will otherwise produce 6.999999999
				cs['beerSetting'] = round(newTemp, 2)
				ser.write("j{mode:b, beerSetting:" + str(cs['beerSetting']))
				time.sleep(1)  # sleep shortly, or something could be added to the string
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: Beer temperature set to " +
									str(cs['beerSetting']) +
									" degrees in web interface")
				raise socket.timeout  # go to serial communication to update Arduino
			else:
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Beer temperature setting" + str(newTemp) +
									" is outside allowed range " +
									str(cc['tempSettingMin']) + "-" + str(cc['tempSettingMax']))
		elif messageType == "setFridge":  # new constant fridge temperature received
			newTemp = float(value)
			if(newTemp > cc['tempSettingMin'] and newTemp < cc['tempSettingMax']):
				cs['mode'] = 'f'
				cs['fridgeSetting'] = round(newTemp, 2)
				ser.write("j{mode:f, beerSetting:" + str(cs['fridgeSetting']))
				time.sleep(1)  # sleep shortly, or something could be added to the string
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: Fridge temperature set to " +
									str(cs['fridgeSetting']) +
									" degrees in web interface")
				raise socket.timeout  # go to serial communication to update Arduino
		elif messageType == "setProfile":  # cs['mode'] set to profile
			# read temperatures from currentprofile.csv
			cs['mode'] = 'p'
			cs['beerSetting'] = temperatureProfile.getNewTemp()
			ser.write("j{mode:p, beerSetting:" + str(cs['beerSetting']))
			time.sleep(1)  # sleep shortly, or something could be added to the string
			print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: Profile mode enabled")
			raise socket.timeout  # go to serial communication to update Arduino
		elif messageType == "setOff":  # cs['mode'] set to OFF
			cs['mode'] = 'o'
			ser.write("j{mode:o}")
			print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: Temperature control disabled")
		elif messageType == "lcd":  # lcd contents requested
			conn.send(lcdText)
		elif messageType == "interval":  # new interval received
			newInterval = int(value)
			if(newInterval > 5 and newInterval < 5000):
				config['interval'] = float(newInterval)
				config.write()
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: Interval changed to " +
									str(newInterval) + " seconds")
		elif messageType == "name":  # new beer name
			newName = value
			if(len(newName) > 3):	 # shorter names are probably invalid
				config['beerName'] = newName
				startBeer(newName)
				config.write()

				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
									"Notification: restarted for beer: " + newName)
		elif messageType == "profileKey":
			config['profileKey'] = value
			config.write()
			changeWwwSetting('profileKey', value)
		elif messageType == "uploadProfile":
			# use urllib to download the profile as a CSV file
			profileUrl = ("https://spreadsheets.google.com/tq?key=" +
				config['profileKey'] +
				"&tq=select D,E&tqx=out:csv")  # select the right cells and CSV format
			profileFileName = '/home/brewpi/' + 'settings/tempProfile.csv'
			if os.path.isfile(profileFileName + '.old'):
				os.remove(profileFileName + '.old')
			os.rename(profileFileName, profileFileName + '.old')
			urllib.urlretrieve(profileUrl, profileFileName)
			if os.path.isfile(profileFileName):
				conn.send("Profile successfuly updated")
			else:
				conn.send("Failed to update profile")
		elif messageType == "getControlConstants":
			conn.send(json.dumps(cc))
		elif messageType == "getControlSettings":
			conn.send(json.dumps(cs))
		elif messageType == "getControlVariables":
			conn.send(json.dumps(cv))
		elif messageType == "refreshControlConstants":
			ser.write("c")
			time.sleep(1)  # sleep shortly, or something could be added to the string
			raise socket.timeout
		elif messageType == "refreshControlSettings":
			ser.write("s")
			time.sleep(1)  # sleep shortly, or something could be added to the string
			raise socket.timeout
		elif messageType == "refreshControlVariables":
			ser.write("v")
			time.sleep(1)  # sleep shortly, or something could be added to the string
			raise socket.timeout
		elif messageType == "loadDefaultControlSettings":
			ser.write("S")
			time.sleep(1)  # sleep shortly, or something could be added to the string
			raise socket.timeout
		elif messageType == "loadDefaultControlConstants":
			ser.write("C")
			time.sleep(1)  # sleep shortly, or something could be added to the string
			raise socket.timeout
		elif messageType == "setParameters":
			# receive JSON key:value pairs to set parameters on the Arduino
			try:
				decoded = json.loads(value)
				ser.write("j" + json.dumps(decoded))
				time.sleep(1)  # sleep shortly, or something could be added to the string
			except json.JSONDecodeError:
				print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
					"Error: invalid json string received: " + value)
			raise socket.timeout
		elif messageType == "programArduino":
			ser.close  # close serial port before programming
			del ser  # Arduino won't reset when serial port is not completely removed
			programParameters = json.loads(value)
			hexFile = '/var/www/uploads/brewpi_avr.hex'
			boardType = 'leonardo'
			port = '/dev/ttyACM0'
			eraseEEPROM = True
			print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
						"New program uploaded to Arduino, script will restart")
			result = programmer.programArduino(boardType, hexFile, port, eraseEEPROM)

			# avrdudeResult = programmer.programArduino(	programParameters['boardType'],
			#							'/var/www/uploads/' + programParameters['fileName'],
			#							config['port'],
			#							programParameters['eraseEEPROM'])
			conn.send(result)
			# restart the script when done. This replaces this process with the new one
			time.sleep(5)  # give the Arduino time to reboot
			python = sys.executable
			os.execl(python, python, * sys.argv)
		else:
			print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
								"Error: Received invalid message on socket: " + message)

		if (time.time() - prevTimeOut) < config['serialCheckInterval']:
			continue
		else:
			# raise exception to check serial for data immediately
			raise socket.timeout

	except socket.timeout:
		# Do serial communication and update settings every SerialCheckInterval
		prevTimeOut = time.time()

		# request new LCD text
		ser.write('l')
		time.sleep(1)  # give the arduino time to respond
		# request Settings from Arduino to stay up to date
		ser.write('s')
		time.sleep(1)  # give the arduino time to respond

		# if no new data has been received for serialRequestInteval seconds
		if((time.time() - prevDataTime) >= float(config['interval'])):
			ser.write("t")  # request new from arduino

		elif((time.time() - prevDataTime) > float(config['interval']) +
										2 * float(config['interval'])):
			#something is wrong: arduino is not responding to data requests
			print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ")
								+ "Error: Arduino is not responding to new data requests")

		time.sleep(1)  # give the arduino time to respond

		while(1):  # read all lines on serial interface
			line = ser.readline()
			if(line):  # line available?
				try:
					if(line[0] == 'T'):
						# process temperature line
						newRow = json.loads(line[2:])

						# print it to stdout
						print time.strftime("%b %d %Y %H:%M:%S  ") + line[2:]
						# write complete datatable to json file

						brewpiJson.addRow(localJsonFileName, newRow)

						# copy to www dir.
						# Do not write directly to www dir to prevent blocking www file.
						shutil.copyfile(localJsonFileName, wwwJsonFileName)

						#write csv file too
						csvFile = open(localCsvFileName, "a")
						lineToWrite = (time.strftime("%b %d %Y %H:%M:%S;") +
							str(newRow['BeerTemp']) + ';' +
							str(newRow['BeerSet']) + ';' +
							str(newRow['BeerAnn']) + ';' +
							str(newRow['FridgeTemp']) + ';' +
							str(newRow['FridgeSet']) + ';' +
							str(newRow['FridgeAnn']) + '\n')
						csvFile.write(lineToWrite)
						csvFile.close()
						shutil.copyfile(localCsvFileName, wwwCsvFileName)

						# store time of last new data for interval check
						prevDataTime = time.time()
					elif(line[0] == 'D'):
						# debug message received
						print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ")
											+ "Arduino debug message: " + line[2:])
					elif(line[0] == 'L'):
						# lcd content received
						lcdText = line[2:]
					elif(line[0] == 'C'):
						# Control constants received
						cc = json.loads(line[2:])

					elif(line[0] == 'S'):
						# Control settings received
						cs = json.loads(line[2:])
					elif(line[0] == 'V'):
						# Control settings received
						cv = json.loads(line[2:])
					else:
						print >> sys.stderr, "Cannot process line from Arduino: " + line
					# end or processing a line
				except json.decoder.JSONDecodeError, e:
					print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
							"JSON decode error: %s" % e)
			else:
				# no lines left to process
				break

		# Check for update from temperature profile
		if(cs['mode'] == 'p'):
			newTemp = temperatureProfile.getNewTemp()
			if(newTemp > cc['tempSettingMin'] and newTemp < cc['tempSettingMax']):
				if(newTemp != cs['beerSetting']):
					# if temperature has to be updated send settings to arduino
					cs['beerSetting'] = temperatureProfile.getNewTemp()
					ser.write("j{beerSetting:" + str(cs['beerSetting']))
					time.sleep(1)  # sleep or something could be added to the string

	except socket.error, e:
		print >> sys.stderr, (time.strftime("%b %d %Y %H:%M:%S   ") +
							"socket error: %s" % e)


ser.close()  # close port
conn.shutdown(socket.SHUT_RDWR)  # close socket
conn.close()