NAME

       comedi_calibrate - COMEDI calibration utility

SYNOPSIS

       comedi_calibrate [-f /dev/comediN]

DESCRIPTION

       comedi_calibrate  is  used  to autocalibrate comedi devices.  Some comedi devices have the
       ability to measure internal stable voltage references and control gains and offsets  using
       programmable  DACs.   On  these  devices, comedi_calibrate determines the proper values to
       feed into the programmable calibration DACs.  These calibration settings are then saved to
       a file, which can be fed to comedi_apply_calibration() and related functions.

       If  comedi_calibrate  finds  an  existing  calibration  file,  it  will  not perform a new
       calibration by default.  It will simply read its calibration information  from  the  file.
       This  behaviour  may be overridden with the --calibrate option, to force a new calibration
       to be performed.

       After obtaining the calibration information for  the  board,  comedi_calibrate  will  then
       apply  a  calibration  setting appropriate for the specified subdevice, channel, and range
       (see the --subdevice ,  --channel  ,  and  --range  options  below).   See  the  comedilib
       documentation for comedi_apply_calibration() for more information.

       comedi_calibrate prints a lot of debugging information as it runs.

LIMITATIONS

       comedi_calibrate  only  works on boards that it understands.  For boards that are known to
       have autocalibration ability, but  are  not  currently  supported,  comedi_calibrate  will
       output  basic  debugging information that is useful for the author to add support for your
       device.  Please send this output to him.

EXAMPLES

       comedi_calibrate --file /dev/comediN
              If no default calibration for /dev/comediN already exists,  perform  a  calibration
              and save results to default location.

       comedi_calibrate --calibrate
              Perform a calibration, using existing calibration (if it exists) as starting point.

       comedi_calibrate --reset --calibrate
              Perform a fresh calibration and save results to default location.

       comedi_calibrate --no-calibrate --subdevice subd.BI--range range --save-file cal_file
              Apply  calibration  for  subdevice  subd,  range  range,  using the settings in the
              calibration file cal_file.

OPTIONS

       comedi_calibrate recognizes the following options:

       -a aref, --aref aref
              Along with --channel, --range and --subdevice, this specifies which calibration you
              want comedi_calibrate leave applied to the board.  The default is 0.

       --[no-]calibrate
              Force calibration to be performed (or not).  By default, comedi_calibrate will only
              perform a new calibration if no existing calibration file  is  found  (see  --save-
              file).

       -c channel,--channel channel
              Along  with  --subdevice,  --range and --aref, this specifies which calibration you
              want comedi_calibrate to leave applied to the board.  The default is 0.

       --[no-]dump
              Perform (or not) dump of various information about state of  calibration  prior  to
              performing new calibration.

       -f /dev/comediN,--file /dev/comediN
              Perform calibration on device /dev/comediN.

       --help Print help for options then exit.

       -q, --quiet
              Don't generate output to stdout.

       -r range, --range range
              Along  with --channel, --subdevice and --aref, this specifies which calibration you
              want comedi_calibrate to leave applied to the board.  The default is 0.

       --[no-]reset
              Reset (or don't reset) calibration subdevice to a reasonable starting point  before
              performing  calibration.   The  default  is --no-reset.  If --no-reset is used, the
              calibration routine will try to use an existing calibration (see --save-file) as  a
              starting point.  This is useful if a single calibration pass is not sufficient, and
              you wish to perform another calibration pass  starting  from  the  results  of  the
              previous pass.

       --[no-]results
              Perform  (or  not)  dump  of  various  information about state of calibration after
              performing new calibration.

       -S file, --save-file file
              Save calibration information to specified file, instead of  default  location.   If
              the  file already exists, comedi_calibrate will also use its contents as a starting
              point for the calibration pass (see --no-reset).

       -s subdevice, --subdevice subdevice
              Along with --channel, --range and --aref, this specifies which calibration you want
              comedi_calibrate to leave applied to the board.  The default is 0.

       -v, --verbose
              Generate more verbose output to stdout, can be specified multiple times

SEE ALSO

       comedi(7)

VERSION

       0.7.x

AUTHOR

       David Schleef, <ds@schleef.org>

       Frank Mori Hess, <fmhess@users.sourceforge.net>

                                                                              comedi_calibrate(8)