sql-edition/servers/SerialClient.py

   1 import os, termios
   2 from time import sleep
   3 import logging
   4
   5 class SerialClientException(Exception): pass
   6
   7 class SerialClient:
   8         BaudRates = {
   9                 110: termios.B110,
  10                 300: termios.B300,
  11                 600: termios.B600,
  12                 1200: termios.B1200,
  13                 2400: termios.B2400,
  14                 4800: termios.B4800,
  15                 9600: termios.B9600,
  16                 19200: termios.B19200,
  17                 38400: termios.B38400,
  18                 57600: termios.B57600,
  19                 115200: termios.B115200,
  20         }
  21
  22         def __init__(self, port = '/dev/ttyS0', baud = 9600):
  23                 self.port = port
  24                 self.baud = baud
  25                 try:
  26                         self.handle = os.open(port, os.O_RDWR)
  27                 except:
  28                         raise SerialClientException('Unable to open port')
  29                 self.oldmode = termios.tcgetattr(self.handle)
  30                 cc = [0]*len(self.oldmode[6])
  31                 cc[termios.VMIN] = 1
  32                 cc[termios.VTIME] = 0
  33                 termios.tcsetattr(self.handle, termios.TCSANOW,
  34                         [
  35                         termios.IGNPAR, # c_iflag
  36                         0, # c_oflag
  37                         termios.CS8|termios.CLOCAL|termios.CREAD, # c_cflag
  38                         0, # c_lflag
  39                         self.BaudRates[self.baud], # c_ispeed
  40                         self.BaudRates[self.baud], # c_ospeed
  41                         cc])
  42                 self.rfh = os.fdopen(self.handle, 'r')
  43                 self.wfh = os.fdopen(self.handle, 'w')
  44                 self.wfh.write('B\n')
  45
  46         def get_fh(self):
  47                 return (self.rfh, self.wfh)
  48
  49         def __del__(self):
  50             pass
  51