calib

Calibrate a touchscreen

Syntax:

calib [options]

Runs on:

Neutrino

Options:

-a alg

Specify the calibration algorithm. Valid algorithms are 3 and 4. Default value is 3.

-b val

Specify the touch point acceptance variance (range 0 - 2000). Enabling this will force bound checking on touch points.

-c

Don't run if a configuration file already exists at /etc/system/config/calib.$(hostname).

-d w,h

The width and height of the screen to be calibrated. If you don't specify this option, calib attempts to get this information from the hardware.

-f file

The name and location of a calibration file to create instead of the default at /etc/system/config/calib.$hostname.

-l limit

Limit the number of samples for each touch point. Default value is 15.

-o offset

Offset for crosshair position, which you can use to tweak calibration. Applicable only with 4-point calibration.

-O

The Origin. Touch screen origin (0,0) is at the lower right side. Default is upper left corner.

-p x, y

The offset position of the calibration region.

-P

Supress prompts (no text is displayed on screen). Prompts are on by default.

-s server

The server node or the device name.

-S

Use small touch targets. Default is large.

-t timer

The done button timer value. Default value is 10.

-v

Verbose output.

-x x

The initial x position.

-y y

The initial y position.

Description:

The calib utility is used to calibrate a touchscreen. Once the touchscreen is successfully configured (i.e. you've created an input.node file), it must be calibrated. The calib utility saves a configuration file at /etc/system/config/calib.$hostname. For information about this file format, see the “Calibration file format” section of the “Writing an Input Device Driver” chapter of the Input DDK documentation.

To invoke the calibration screen:

1. Start Photon.
2. Run calib.
3. Touch the bullseye target on the screen.
4. Touch the Press to Complete Calibration button to finish calibration.

Examples:

Calibrate a quarter of a standard 640x480 VGA screen (the driver will cover only part of the screen):

calib -d 320,240