© 2009 Microchip Technology, Inc.

DS41393A-Page 19

7.15.3 Calibrate - 0x14

Enter “calibration” mode. This instructs the controller to enter a mode of accepting the next four touches as the

calibration point coordinates. See section Calibration of Touch Sensor with Controller for an example.

Completion of calibration mode will automatically store the calibration point coordinates in on-board controller

memory and set (to 1) the CCE bit of the TouchOptions register. This bit enables the controller to report touch

coordinates that have been processed with the pre-collected calibration data.

The “calibration” mode will be cancelled by sending any command before the mode has been completed.

Send

: <0x55><0x02><0x14><Calibration Type>

Calibration Type

Description

0x04

4 point

Receive : <0x55><0x02><Response><0x14>

for initial command response

<0x55><0x02><Response><0x14>

for response to 1

<0x55><0x02><Response><0x14>

for response to 2

<0x55><0x02><Response><0x14>

for response to 3

<0x55><0x02><Response><0x14>

for response to 4

To provide for proper touch orientation, the four sequential calibration touches must be input in the following

physical order on the touch sensor.

# 1

# 2

Upper Left

Upper Right

Touch Sensor

# 4

# 3

Lower Left

Lower Right