OVERVIEW
  
  This is a very fast and simple explanation of using these tools for the
  Dallas Semi 1921 iButton.  These instructions may help you run other
  such ibutton devices.
COMPILE AND INSTALL
  ./configure <your parameters or `-help' for options listing>
  make install
USAGE
  The fisrt thing you will want to do is search your serial port for all
  of the devices on the serial bus.  First start by setting your
  MLAN_DEVICE environment variable so that the serial port is known:
    (t)csh:
    setenv MLAN_DEVICE /dev/tty00
    (ba)sh:
    MLAN_DEVICE=/dev/tty00
    export MLAN_DEVICE
    Note: For Linux OSes, your first serial port may be /dev/ttyS0
    Note: If you receive permission denied errors, please see your
      system administrator for appropriate permissions assignment
      for your user.
  
  This should result in output similar to:
    $ ./search
    Serial[0]:  xxxxxxxxxxxxxxxx -- DS1921 Thermochron
    Serial[1]:  xxxxxxxxxxxxxxxx -- DS9097u 1-wire to RS232 converter
    $ 
    
    Note: "xxxxxxxxxxxxxxxx" will be replaced by your serial numbers
  With these serial numbers and your serial port, you are all ready to
  go.  First you must set up your ibutton to have a mission.  A mission
  is simply telling the ibutton what to 
APPS
  search
  
    Takes no required parameters but does require that the MLAN_DEVICE
    environment variable points to the serial device
    (default: /dev/tty00) which has the ibutton bus.
    -r
      check for missions on each of the devices on the bus
  1921mission
    Sets the mission (sampling rate) for the device.  This takes one
    required parameter as the <serial number> for the device to
    mission.
    <serial number>
      The serial number of the device to set a mission for
    -r
      Rollover.  When the ibutton reaches it's memory maximum, start
      writing over the oldest entry.  Round-robin fashion.
    -s <sample rate>
      The rate of sampling.  This is in minutes.
    -d <mission delay>
      The number of minutes to delay before taking samples.
        The number of minutes to delay before taking samples.
    -l <low alert>
    -h <high alert>
  sample_devices
    Polls all devices on the bus for changes and logs them to a log
    file.  Optionally, the changes can also be published to a multicast
    group.
    -b <busdev>
      Serial device containing the bus to poll (i.e. /dev/tty00)
    -l <logfile>
      File to write log entries.  These are general logs.
    -c <logdir>
      Directory to write individual snapshots.  These will be named the
      serial number of the ibutton device and will be located in this
      directory.
  1921dump
    Dumps all setting for the mission as well as the current statistics
    and data stored on the device.
    <serial number>
      The serial number of the device to retrieve all the settings
      for.