Accessing shell any time

If you want create a smart app that will communicate with RFC any time, there is a sequence that resets the shell to its default state under any condition (no need to cycle USB). The code is in python, but can be ported to any language you use. The idea is to send command stdshell or stdshellnk in multiplexed packet mode (for cases the cube was in this mode) in order to switch it to default mode.

## ########################################
## somewhere in code open sline serial port
## ########################################
sline = serial.Serial()
## ########################################
def init_basic_shell(kill_clean = 1):
  sline.timeout = 0

  if (kill_clean):
    #"stdshell" in multiplex mode, see below
    cmd = "SQ\x00\0x0a\x00stdshell\x0d\x70\x71\x00\x73"
  else:
    #"stdshellnk" in mulitplex mode, see below
    cmd = "\x53\x51\x00\x0c\x00\stdshellnk\x0d\x49\x71\x00\x73"

  sline.write(cmd)
  # we have to send once "\r" for case the multiplex was off
  # and we need to discard nonsense commands to obtain the prompt
  sline.write("\r")
  time.sleep(0.2)
  sline.flushInput()

  ##############################################################
  # at this moment, the cube should be communicating in a simple
  # shell with prompt ON and echo OFF
  ##############################################################
  # stdshell kills all ongoing apps
  # if you do not want to interfere
  # and let running apps continue,
  # use "stdshellnk" instead (kill_clean=0)
  ##############################################################
  # if you don't kill a running script on cube, the script can
  # interfere with the shell with its output -
  # use only if you know what you are doing :-)
  ##############################################################