addons/hw_scale/mettler.py

   1 #!/usr/bin/python
   2 import serial
   3 import time
   4 import sys
   5 from bitstring import BitArray
   6
   7 path = "/dev/serial/by-id/usb-METTLER_TOLEDO_15_kg_DI_Firmware_CKOR_F_Ser_CDC-if00"
   8
   9 device = serial.Serial(path,
  10         baudrate = 9600,
  11         bytesize = serial.SEVENBITS,
  12         stopbits = serial.STOPBITS_ONE,
  13         parity   = serial.PARITY_EVEN,
  14         #xonxoff  = serial.XON,
  15         timeout  = 0.1,
  16         writeTimeout= 0.1)
  17
  18 if len(sys.argv) == 1:
  19     cmd = 'weight'
  20 else:
  21     cmd = sys.argv[1]
  22
  23 def write(stuff):
  24     print stuff
  25     device.write(stuff)
  26
  27 def read_answer():
  28     answer = []
  29     while True:
  30         char = device.read(1)
  31         if not char:
  32             return answer
  33         else:
  34             answer.append(char)
  35
  36 def print_answer(answer):
  37     print answer
  38     if '?' in answer:
  39         status = answer[answer.index('?')+1]
  40         print 'status_bits: '+BitArray(int=ord(status),length=8).bin
  41
  42
  43 if cmd == 'weight':
  44     while True:
  45         time.sleep(0.25)
  46         write('W')
  47         time.sleep(0.25)
  48         print_answer(read_answer())
  49
  50 if cmd == 'interactive':
  51     weight = 0
  52     status = ''
  53     while True:
  54         time.sleep(0.25)
  55         device.write('W')
  56         answer = read_answer()
  57         if '?' in answer:
  58             oldstatus = status
  59             b = answer[answer.index('?')+1]
  60             if b == '\x00' or b == ' ':
  61                 pass # ignore status
  62             elif b == 'B':
  63                 status = 'too_heavy'
  64             elif b == 'D':
  65                 status = 'negative'
  66             elif b == 'A' or b == 'Q' or b == '\x01':
  67                 status = 'moving'
  68             else:
  69                 status = 'unknown'
  70                 print b.__repr__(), BitArray(int=ord(b),length=8).bin
  71             if oldstatus != status:
  72                 print status
  73         else:
  74             oldweight = weight
  75             answer = answer[1:-1]
  76             if 'N' in answer:
  77                 answer = answer[0:-1]
  78             weight = float(''.join(answer))
  79             if oldweight != weight:
  80                 print weight
  81
  82
  83 elif cmd == 'zero':
  84     time.sleep(1)
  85     write('Z')
  86     time.sleep(1)
  87     print_answer(read_answer())
  88
  89 elif cmd == 'test':
  90     time.sleep(1)
  91     write('A')
  92     time.sleep(1)
  93     write('B')
  94     time.sleep(1)
  95     answer = read_answer()
  96     if '@' in answer:
  97         print 'all test passed'
  98     else:
  99         print_answer(answer)
 100