serial_thing.py

import serial
import string
import random
import time
import _mysql
import _mysql_exceptions
import re

import config

# Maximum Length Username - 17 characters
Greetings = ["Welcome __",
             "Hello __",
             "Hey __"]

# Maximum Length Quote - 52 characters
Quotes = ["Be great today",
          "Challenge yourself",
          "Dream on",
          "Practice gets you perfect",
          "Live long and prosper",
          "May the force be with you",
          "Preparing to power down and begin diagnostics"]

def openDoor(username):
    gIdx = random.randint(0, len(Greetings) - 1)
    gMsg = Greetings[gIdx] + username
    qIdx = random.randint(0, len(Quotes) - 1)
    qMsg = Quotes[qIdx]

    ser.write(gMsg)
    time.sleep(0.1)
    if random.random() < 0.4:
        ser.write(qMsg)
    else:
        ser.write('+')

def ByteToHex( byteStr ):
    """
    Convert a byte string to it's hex string representation e.g. for output.
    """
    
    # Uses list comprehension which is a fractionally faster implementation than
    # the alternative, more readable, implementation below
    #   
    #    hex = []
    #    for aChar in byteStr:
    #        hex.append( "%02X " % ord( aChar ) )
    #
    #    return ''.join( hex ).strip()        

    return ''.join( [ "%02X " % ord( x ) for x in byteStr ] ).strip()

#If the button has been pressed more than 1 second ago, reset its status to "false".
def checkIfReleased():
    global buttonPressed
    if time.time() - lasttime > 1 and buttonPressed is True:
        print "Button Released!"
        buttonPressed = False

#controlDoor(): Releases the door if more than "delay" seconds have passed 
#since the door was last energized ("doortime"). 
def controlDoor():
    global doortime
    delay = 2
    if doortime != 0:
        if time.time() - doortime > delay:
            doortime = 0
            print "Door Released"

ser = serial.Serial('/dev/ttyUSB0', 9600, timeout = 0.5)
print ser.portstr

lasttime = 0
buttonPressed = False
doortime = 0

while True:
    s = ser.read(16)
    ser.flushInput()
    #print ByteToHex(x)
    checkIfReleased()
    controlDoor()
    if len(s) < 14:
        continue
    #if string.find("0x7E", ByteToHex(s[0])) != -1:
    done = 0
    for i in range(len(s)):
        #print(ByteToHex(s[i]))
        if string.find("0x83", ByteToHex(s[i])) != -1:
            if len(s) - i >= 3:
                if string.find("0x00", ByteToHex(s[i+1])) != -1 and string.find("0x03", ByteToHex(s[i+2])) != -1:
                    # print "Last Timestamp: "+time.strftime("%H:%M:%S")
                    newtime = time.time()
                    # print lasttime
                    # print newtime
                    if newtime - lasttime > 2:
                        print "Button Pressed! Timestamp: "+time.strftime("%H:%M:%S")
                        try:
                            db=_mysql.connect(host="localhost", user=config.USER, passwd=config.PASSWD,db=config.DB)
                            db.query("""INSERT INTO events(type) VALUES('remote')""") 
                            db.close()
                        except _mysql.Error:
                            print "Shit! DB Error!"
                        except NameError:
                            print "No DB was initialized"
                        buttonPressed = True
                        doortime = newtime
                        print "Door opened"
                        openDoor("fellow p-spacer")
                    lasttime = newtime
                    done = 1
    if done == 0 and len(s) == 16 and string.find("0x02", ByteToHex(s[0])) != -1 and string.find("0x03", ByteToHex(s[15])) != -1:
        print "ID Card detected!"
        #s = ser.read(15)
        #print s[1:13]
        found = 0
        for line in open("cards.txt"):
            #Check if the line contains the number of the card
            if s[1:13] in line:
                found = 1
                #line format: cardnumber\tusername\n
                username = line.split("\t")[1].split("\n")[0]

                #Check if the card has been cancelled
                if re.match("#", line):
                    print "Card " + s[1:13] + " rejected for user " + username
                    break
                
                #If the card has been found in the file and is valid, open the door
                print "Card belongs to: " + username
                print "Accepted!"
                newtime = time.time()
                doortime = newtime
                print "Door opened"
                openDoor(username)
                
                try:
                    db=_mysql.connect(host="localhost", user=config.USER, passwd=config.PASSWD,db=config.DB)
                    db.query("""INSERT INTO events(type, name, card) VALUES('card', '"""+username+"""', '"""+s[1:13]+"""')""") 
                    db.close()
                except _mysql.Error:
                    print "Shit! DB Error!"
                except NameError:
                    print "No DB was initialized"
                break
        if found == 0:
            print "Unknown Card Number: " + s[1:13]
    
    elif done == 0:
        print "Got undefined data: " + s + " Hex: " + ByteToHex(s)
        
    checkIfReleased()
    controlDoor()

    ser.flushInput()
ser.close()