Raspberry Pi [Master node]

#!/usr/bin/env python

# Importing modules
import serial
import time
import datetime

# Definition of UNIX shell colors
class bcolors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[93m'
    TEST = '\033[92m'
    ENDC = '\033[0m'


# Holder for active serial ports
serialPorts = []

# Populated by the Ardunios by either "TIL" or "PUST"
# This decides the name of the logfile for this arduino.
typeOfSensorNode = []

# Holder for generated files
filenames = []
files = []

# messages[0] = '1' is used to ask the Arduino's for sensor data
# messages[1] = '2' is used for probing each active serial port and checking for an answer 'PUST' or 'TIL'
messages = ['1', '2']

# Time between each sensor log.
# Change this if you want to alter the frequency of data transfers.
timeBetweenDataTransfers = 10

# Number of connected devices.
# Change if you want to add more or less sensor nodes.
numberOfArduinoDevices = 2

# Serial Connection settings.
# Do not change.
baudrate = 9600
parity = serial.PARITY_NONE
stopbits = serial.STOPBITS_ONE
bytesize = serial.EIGHTBITS
timeout = 1

# Routine that probes the first 100 possible Arduino-COMs.
# This routine populates serialPorts.
def establishSerialConnections():
    counter = 0
    print(bcolors.OKGREEN + "\n--- Establishing serial connections ---" + bcolors.ENDC)
    while (counter < 100):
        try:
            ser = serial.Serial(
                port= "/dev/ttyACM" + counter.__str__(),
                baudrate = baudrate,
                parity = parity,
                stopbits = stopbits,
                bytesize = bytesize,
                timeout = 1
            )
            serialPorts.append(ser)
            ser.close()
            ser.open()
            print ("Found open device at /dev/ttyACM" + counter.__str__())

        except IOError:
            None

        counter += 1
    print(bcolors.OKGREEN + "--- Serial connections established --- \n\n" + bcolors.ENDC)

# Routine checking what type of sensorNode we found.
# This routine populates typeOfSensoNodes.
# It is also detrimental to ensure established connection.
# If the number of established connections is not the number of expected Arduinos, the program will shut down.
def checkDeviceConnectivity():
    print(bcolors.OKGREEN + "--- Checking if devices are sensor nodes ---" + bcolors.ENDC)
    establishedConnections = 0
    for portNumber in range(0, numberOfArduinoDevices):
        print ('Writing to Arduino at ' + serialPorts[portNumber].port.__str__())
        serialPorts[portNumber].write(messages[1])
        recievedData = serialPorts[portNumber].readline()



        print("First package from Arduino is: " + recievedData)
        if (recievedData == "TIL" or recievedData == "PUST"):
            print ('We found a sensor node')
            typeOfSensorNode.append(recievedData)
            establishedConnections += 1

    print(bcolors.OKGREEN + "--- Done checking if devices are sensor nodes --- \n\n" + bcolors.ENDC)
    if (establishedConnections == numberOfArduinoDevices):
        return True
    else:
        return False

# Routine generating filenames, using typeOfSensorNode.
# File names are hard coded to /home/pi/Desktop/log/filename.csv.
# Each file is named with millisecond precision, meaning files will never generate the same names.
def generateFileNames():
    for device in range(0, numberOfArduinoDevices):
        filenames.append("/home/pi/Desktop/log/"+typeOfSensorNode[device].__str__()+'_Arduino_nr_'+device.__str__()+'_'+datetime.datetime.now().__str__()+'.csv')
        print ("Created file: " + filenames[device].__str__())

# Routine creating actual measurement files and fills in first two rows.
def createMeasurementFiles():
    print(bcolors.OKGREEN + "--- Generating measurement files ---" + bcolors.ENDC)
    generateFileNames()
    for device in range(0, numberOfArduinoDevices):
        files.append(open(filenames[device], "w+"))
        files[device].write('Date;Time;Temperature;Relative Humidity;CO2;Formaldehyde Start;Control;High bit;Low bit;Reserved;Reserved;High bit;Low bit;Checksum;PM1.0;PM2.5;PM4.0;PM10;NCPM0.5;NCPM1.0;NCPM2.5;NCPM4.0;NCPM10.0;Typical Particle Size')
        files[device].write("\r\n")
        files[device].close()
    print(bcolors.OKGREEN + "--- Done generating measurement files --- \n\n" + bcolors.ENDC)


# Function for reading from the nodes.
# All write functionality here should at a later point be written in a writeToFile-routine.
def readFromArduino_writeToFile():
    for device in range(0, numberOfArduinoDevices):
        print ('Reading from Arduino at ' + serialPorts[device].port.__str__())
        recievedData = serialPorts[device].readline()
        #print ("Recieved: " + recievedData.__str__())
        if (recievedData != None):
            print ('Read successfully from ' + serialPorts[device].port.__str__())
        else:
            print ('Failed')
        files[device] = open(filenames[device], "a")
        files[device].write(datetime.datetime.now().date().__str__())
        files[device].write(";")
        files[device].write(datetime.datetime.now().time().__str__())
        files[device].write(recievedData)
        files[device].write("\r\n")
        files[device].close()

# Routine for writing a message to all the sensor nodes.
def writeToArduino(message):
    for device in range(0, numberOfArduinoDevices):
        serialPorts[device].write(message)


establishSerialConnections()
connection_established = checkDeviceConnectivity()
createMeasurementFiles()

if connection_established:
    print(bcolors.HEADER + "Connection is established, going into measurement mode \n \n" + bcolors.ENDC)
    while True:
        print(bcolors.OKGREEN + "--- Performing measurement ---" + bcolors.ENDC)
        writeToArduino(messages[0])
        readFromArduino_writeToFile()
        print(bcolors.OKGREEN + "--- Measurement done --- \n\n" + bcolors.ENDC)
        print((bcolors.TEST + "Waiting between measurements. Press CTRL+Z to exit \n\n" + bcolors.ENDC))
        time.sleep(timeBetweenDataTransfers)
else:
    print ('Failed finding enough Arduino Devices, shutting down')