AR1000_16 Datasheet, PDF (23/61 Pages) Microchip Technology – AR1000 Series Resistive Touch Screen Controller

AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER
7.0 TOUCH REPORTING
PROTOCOL
Touch coordinates are sent from the controller to the
host system in a 5-byte data packet, which contains the
X-axis coordinate, Y-axis coordinate, and a “Pen-Up/
Down” touch status.
The range for X-axis and Y-axis coordinates is from 0-
4095 (12-bit). The realized resolution is 1024, and bits
X1:X0 and Y1:Y0 are zeros.
It is recommended that applications be developed to
read the 12-bit coordinates from the packet and use
them in a 12-bit format. This enhances the application
robustness, as it will work with either 10 or 12 bits of
coordinate information.
The touch coordinate reporting protocol is shown below
in Table 7-1.
TABLE 7-1: TOUCH COORDINATE REPORTING PROTOCOL
Byte #
Bit 7
Bit 6
1
1
R
2
0
X6
3
0
0
4
0
Y6
5
0
0
where:
• P: 0 Pen Up, 1 Pen Down
• R: Reserved
• X11-X0: X-axis coordinate
• Y11-Y0: Y-axis coordinate
Bit 5
R
X65
0
Y5
0
Bit 4
R
X4
X11
Y4
Y11
Bit 3
R
X3
X10
Y3
Y10
Bit 2
R
X2
X9
Y2
Y9
Bit 1
R
X1
X8
Y1
Y8
Bit 0
P
X0
X7
Y0
Y7
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DS40001393C-page 23