18 3M™ MicroTouch™ Controller EX USB Reference Guide
3M Touch Systems, Inc. Proprietary Information -- 29489v05
Controller Initialization
To initialize the EX USB controller, 3M Touch Systems recommends that the host
system issue a Reset command whenever the host system is powered on and is attempting
to establish communication with the controller.
Coordinate Data Report 1
Coordinate Data Report 1 is used to transfer both the raw and adjusted coordinate data to
the host. This report, when activated, is sent to the host whenever new data is available. It
is an asynchronous report activated by default at power up.
Table 6. Coordinate Data Report
Offset Field Size Value Description
0 Report ID 1 0x01 USB report ID number
1 Loop Counter 1 0xXX Report synchronization
2 Status byte 1 0xXX Pen/finger touch status
3 X Compensated 2 0xXXXX Compensated X coordinate
5 Y Compensated 2 0xXXXX Compensated Y coordinate
7 X Raw 2 0xXXXX Raw X coordinate
9 Y Raw 2 0xXXXX Raw Y coordinate
The main purpose of the loop counter is to effectively put a time stamp on the output
data. Data produced in the same tick will have the same timestamp. This can be used to
match the final coordinate data with other data that was used to produce it. This is not a
sequential number.
The status byte contains information pertaining to whether the sensor is being touched.
Table 7. Touch Status
Bit Description
7 Always 1
6 Proximity
1 when touching
0 when not touching
5 Reserved
4 Reserved
3 Reserved
2 Reserved
1 Reserved
0 Reserved
The raw X and Y coordinate data are generated directly from the sensor. The range of
values is -8192 to 8191. The X and Y adjusted coordinate data is derived by applying
calibration information. The range of values is 0 to 65,535. Coordinate data is sent LSB
first.
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