3M
™ Multi-Touch ASIC Controller Reference Guide
31
3M Touch Systems, Inc. Proprietary Information
The illustration below shows the coordinates of the calibration targets and display
corners. The corners show the video coordinates in parentheses and the touch screen
coordinates in brackets. Note that the touch screen coordinates for the serial interface
have their origin in the lower-left corner.
Note:
Other screen resolutions will scale proportionally. The touch coordinates will not change.
Mode Down Up
Syntax:
<SOH>
MDU<
CR>
Response:
<SOH>
0
<CR>
Positive response.
Description:
Limits touch reports to touchdown and liftoff events only.
Mode Inactive
Syntax:
<SOH>
MI
<CR>
Response:
<SOH>
0
<CR>
Positive response.
Description:
Turns off touch reports.
Mode Stream
Syntax:
<SOH>
MS
<CR>
Response:
<SOH>
0
<CR>
Positive response.
The controller will respond with acknowledge (ACK) for compatibility. This format is
the only format supported by this controller.
Description:
This is the default mode of operation at power up. Touch reports include touchdown and
liftoff events as well as continuing touches.
Null Command
Syntax:
<SOH>
Z
<CR>
Response:
<SOH>
0
<CR>
Positive response.
Description:
Queries the controller and waits for a response.
(0, 1049) [0, 32767]
(1679, 1049) [32767, 32767]
Upper Right Calibration Target
X = 1679
– (1920 x 1/8) = 1679 – 240 = 1439
Y = 0 + (1080 x 1/8) = 0 + 135 = 135
Lower Left Calibration Target
X = 0 + (1920 x 1/8) = 0 + 240 = 240
Y = 1049 - (1080 x 1/8) = 1049 - 135 = 914
(0, 0) [0, 0]
(
1679, 0) [32767, 0]
(240, 914)
(1439, 135)
