xmodem for python

Hi All:

I am wiriting a program that requires the use of XMODEM to transfer data from a sensor device. I'd like to avoid having to write my own XMODEM code, so I was wondering if anyone knew if there was a python XMODEM module available anywhere?

Al

From stackoverflow

• I think you’re stuck with rolling your own.

  You might be able to use sz, which implements X/Y/ZMODEM. You could call out to the binary, or port the necessary code to Python.

• Here is a link to XMODEM documentation that will be useful if you have to write your own. It has detailed description of the original XMODEM, XMODEM-CRC and XMODEM-1K.

  You might also find this c-code of interest.

• You can try using SWIG to create Python bindings for the C libraries linked above (or any other C/C++ libraries you find online). That will allow you to use the same C API directly from Python.

  The actual implementation will of course still be in C/C++, since SWIG merely creates bindings to the functions of interest.

• def xmodem_send(serial, file):
  t, anim = 0, '|/-\\'
  serial.setTimeout(1)
  while 1:
      if serial.read(1) != NAK:
          t = t + 1
          print anim[t%len(anim)],'\r',
          if t == 60 : return False
      else:
          break
  
  p = 1
  s = file.read(128)
  while s:
      s = s + '\xFF'*(128 - len(s))
      chk = 0
      for c in s:
          chk+=ord(c)
      while 1:
          serial.write(SOH)
          serial.write(chr(p))
          serial.write(chr(255 - p))
          serial.write(s)
          serial.write(chr(chk%256))
          serial.flush()
  
          answer = serial.read(1)
          if  answer == NAK: continue
          if  answer == ACK: break
          return False
      s = file.read(128)
      p = (p + 1)%256
      print '.',
  serial.write(EOT)
  return True