Datasheet

 2009-2012 Microchip Technology Inc. Preliminary DS41393B-page 27
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.
where:
• P: 0 Pen Up, 1 Pen Down
• R: Reserved
• X11-X0: X-axis coordinate
• Y11-Y0: Y-axis coordinate
TABLE 7-1: TOUCH COORDINATE REPORTING PROTOCOL
Byte # Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1 1 RRRRRRP
2 0 X6 X65 X4 X3 X2 X1 X0
3 0 0 0 X11 X10 X9 X8 X7
4 0 Y6 Y5 Y4 Y3 Y2 Y1 Y0
5 0 0 0 Y11 Y10 Y9 Y8 Y7