EX II Controller Communications
21
3M Touch Systems Proprietary Information
Table 3 Firmware Commands for EX II Development
Command
Code
Description
Calibrate
Extended
CX
Initiates an interactive 2-point calibration.
Calibrate Raw
CR
Collects the raw X and Y coordinates before normal scaling, linearization, and
filtering process.
Diagnostic
DX
Determines if there is a problem with the touch screen.
Format Raw
FR
Returns the signal level (amount of touch) of each of the four touch screen
corners in digital format.
Format Tablet
FT
Outputs the X/Y touch coordinate data in a five-byte packet. Preferred for current
development.
Mode Stream
MS
Sends a continuous stream of X/Y coordinate data when you touch the screen.
Name
NM
Returns a controller identifier string.
Null Command
Z
Queries the controller and waits for a response.
Output Identity
OI
Identifies the controller type and the firmware version.
Parameter Set
P
pds
[
b
]
Lets you adjust the communication parameters (parity, data bits, and stop bits) of
the controller.
Reset
R
Initializes the hardware and the firmware, causes the controller to stop sending
data, and recalculates the environmental conditions.
Restore Defaults
RD
Returns the controller to the factory default operating parameters. Note: the serial
port is reset to N81 format tablet and 2-point calibration is lost.
Unit Type Verify UV
Identifies the touch screen controller on your system.
Calibrate Extended
Syntax:
<SOH>
CX
<CR>
Note:
This command should not be used when TouchWare or MT 7 software is being
used. The CX command will interfere with the auto orientation algorithm. To calibrate,
use the 2- or 4-point calibration in TouchWare or MT 7 software.
Description:
Initiates an interactive 2-point calibration.
During the calibration process, you define the active area of the touch screen by mapping
locations to an absolute X/Y coordinate system. You touch two
target areas
on the
screen. Touching the target areas sends the X/Y coordinates for those touch points to the
controller. The controller calculates all other touch points based on these two points.
The Calibrate Extended command sets the calibration targets (points) inward from the
corner of the video image. Setting the targets inward makes the calibration process easier
and more accurate.
Guidelines for Calibrate Extended
Here are several guidelines for using the Calibrate Extended command:
•
The controller uses the data immediately before liftoff to register a calibration touch.
Therefore, you can touch the screen, move your finger to the target, hold for a few
seconds, and then lift off. Instructing users to touch this way results in a more
accurate calibration.
