LM8500 datasheet(18/20 Pages) NSC

18 / 20 page

14.0 Calibration (Continued)

send a reply byte of $CC to the TS driver. At this point, the

TS driver should either notify the user to redo the calibration

point or automatically redo the calibration again. If the self-

test was successful, the device will send a reply byte of $CB

to the TS driver.

14.3 CALIBRATION PROCEDURES WITH

COORDINATES CHECKING DISABLED

To do TS calibration with coordinates checking disabled, first

ensure the Calibration Coordinates Checking is disabled on

the device. This can be accomplished by sending a com-

mand byte of $B1 (Read Parameters command) and check-

ing the 5th bit of the 12th reply byte is not set. Alternatively,

if the device is set to Calibration Coordinates Checking

disabled as default, this step can be skipped.

The TS driver sends the command byte to do calibration

($BD). The TS driver should wait for the reply bytes and

ensure it is the same command bytes it sent. The device

waits for a touch to be detected on the panel. Once a touch

is detected, the device save the values into the internal flash

and send a reply byte of $C4 to the TS driver. The TS driver

can now send a command byte to do the next calibration

point. Since the Calibration Checking is disabled, the TS

driver should ensure the calibration point is within the range

of the calibration cross.

Once all the calibration points are done, the device does a

self-test. If the self-test was not successful, the device will

send a reply byte of $CC to the TS driver. At this point, the

TS driver should either notify the user to redo the calibration

point or automatically redo the calibration again. If the self-

test was successful, the device will send a reply byte of $CB

to the TS driver.

15.0 Revision History

Date

Section

Summary of Changes

October 2002

Initial release.

May 2003

All sections

Removed LM8400 part.

Brownout Reset

Updated section to reflect the change and made external reset circuitry

optional.

July 2003

Advanced Command Bytes

Descriptions

Added command byte $A5

Updated controller reply bytes

December

2003

Advanced Command Bytes

Descriptions

Added description for command byte $A5

LM8500 bảng dữ liệu(PDF) 18 Page - National Semiconductor (TI)

LM8500 bảng dữ liệu(HTML) 18 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

bảng dữ liệu tải về

Link URL