#!usr/bin/python
# arduino_stream.py
# service to write the arduino measuring data from USB input
# to a file, webserver can show by PHP
# KLL engineering 2013 01 08 
# change 1 minute file to ramdisk
# change database filename arduinodb year month day .csv ( new day, new file )
# except statement still not work???

import serial
import time
import glob

# _________________________________________________________________
def scan():
    """scan for available ports. return a list of device names."""
    return glob.glob('/dev/ttyS*') + glob.glob('/dev/ttyUSB*') + glob.glob('/dev/ttyACM*')

# _________________________________________________________________
def read_save():

    sfiledata="/run/shm/arduinodata.csv"                  # one actual record
    syear  = time.strftime("%Y")
    smonth = time.strftime("%m")
    sday   = time.strftime("%d")
    sfiledb="/var/www/arduinodb" + syear + smonth + sday + ".csv"     # of max 1440 minute values

    foldtime = time.time()
    fnewtime = time.time()
    fstore = 100.0                                         # sec
    
    while ser.isOpen() :
          measureline = ser.readline()
          stime=time.strftime(",%Y,%m,%d,%H,%M,%S,")
                                                      # get timing for store data to file
          fnewtime = time.time()
          fdtime = fnewtime-foldtime

          sdatline = stime + measureline
          # print sdatline + " dt: " + str(fdtime)      # diagnostic
          
          if fdtime >= fstore:                         # only store every "fstore" seconds
                foldtime = fnewtime
                fdat = open(sfiledata,"w")             # open w file for write only one line
                fdat.write(sdatline)
                fdat.close()                           # close the file
                fdatb = open(sfiledb,"a")              # open a file for append
                fdatb.write(sdatline)
                fdatb.close()                          # close the file
                # print sdatline                         # temporary show
    



if __name__=='__main__':
    print "Found ports:"
    for name in scan():
        print name
        time.sleep(1)       # give time to free ports
        
    sport = "/dev/ttyACM0"
    for inum in range(1,7):                             # try 3 times
        if inum == 4:
            sport = "/dev/ttyUSB0"                      # try 3 times
        # print str(inum) + " we test " + sport
        ser = serial.Serial(sport, 115200, timeout=60)  # arduino is reset!
        # try to open
        try:
            ser.open()
            # print " looks good"
            read_save()            
            ser.close()

#       except serial.SerialException:
        except Exception as ex:
             print "Failed to connect to port on: ", ser
             raise ex
#            print " serial problem "
        ser.close()
        pass
        
        time.sleep(1)       # give time

    
    print "end"