docs: def listSerialPorts():
  	"""
  	http://pyserial.readthedocs.io/en/latest/shortintro.html
  
  	This calls the command line tool from pyserial to list the available
  	serial ports.
  	"""
  	cmd = 'python -m serial.tools.list_ports'
  	err, ret = commands.getstatusoutput(cmd)
  	if not err:
  		r = ret.split('\n')
  		ret = []
  		for line in r:
  			if line.find('/dev/') >= 0:
  				line = line.replace(' ', '')
  				ret.append(line)
  	return err, ret