#!usr/bin/python
# arduino_stream_PMS3.py
# service to write the arduino measuring data from USB input
# to a file, processing.. can read to show scope graph
# KLL engineering 2013 11 20


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():
  batchcount = -1                             # init
  maxfile = 10
  batchfull = 0                               # init 
  batchline = 0                               # init
  lastlinecount = 0
  foldtime = time.time()
  fnewtime = time.time()
  CSVpath = '/run/shm/'
  CSVname = 'PMS3_'
  CSVext  = '.csv'
  pointfilename = '/run/shm/current.txt'
  filename = 'not saved'
  temp_list = []                              # prepare array of recordlines
    
  while ser.isOpen() :
        sline = ser.readline()
        sline = sline.strip('\r')             # arduino send CR + NL
        if len(sline) >5:                     #   0,0,0, shortest good line
          batchline = batchline +1
          #print ( str(batchline) + ': ' + sline)
          temp_list.append(sline)
          if len(sline) > 15:                 # must be the header line new batch
                foldtime = fnewtime
                fnewtime = time.time()
                lastlinecount = batchline         
                batchline = 0                     # reset
                batchcount = batchcount +1
                if batchcount > 0:                 # must be following batch after prog start
                    filename = CSVpath + CSVname + str(batchcount) + CSVext
                    fdat = open(filename,"w")    # open w file for write only a for append
                    for tline in temp_list:
                        fdat.write(tline)
                    fdat.close()                 # close the file
                    fdatp = open(pointfilename,"w")
                    fdatp.write(filename)           # points to the actual datafile in ringbuffer
                    fdatp.close()
                    if batchcount == maxfile:
                        batchcount = 0
                pass # not very first headerline / fullbatch
                temp_list = []                # empty array?
                print ('batch finished see: ' +str(lastlinecount) +' lines, need ' + str(fnewtime-foldtime) + ' sec, saved to: ' + filename)
                #print temp_list
        pass # len>5  
  pass #while

# _________________________________________________________________

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()
            read_save()
            ser.close()

        except Exception as ex:
             print "Failed to connect to port on: ", ser
             raise ex

        ser.close()
        pass

        time.sleep(1)       # give time


    print "end"
# _________________________________________________________________