Datasheet

MTCH6301 PROJECTED CAPACITIVE TOUCH CONTROLLER
DS41663A-page 10  2012 Microchip Technology Inc.
5.0 COMMUNICATION PROTOCOL
5.1 Overview
The MTCH6301 has two basic communication types:
Touch & Gesture Protocol, and Command Protocol.
Touch & Gesture Protocol
Fully processed touch coordinates and gestures will be
transmitted immediately as they are processed by the
MTCH6301. Since it is a slave device, the INT pin will
be asserted whenever one of these packets is ready for
transmission. This requires the master controller to ini-
tiate a READ command to receive the touch or gesture
packet.
Command Protocol
All other commands are invoked by the I
2
C master
controller. Commands are used for configuring and
controlling the device.
Master Read Details
Please note that any read from the controller by the
master, including both touch & gesture protocol and
command protocol, will be prefixed by a single byte.
This single byte denotes the number of bytes that are
to be transferred. This byte is NOT represented in the
tables and figures for the protocol, but is detailed in
Figure 5-6 and Figure 5-7.
5.2 Touch Protocol
The packet in Tabl e 5 - 1 is transmitted for each touch
that is present on the sensor.
5.3 Gesture Protocol
The packet in Tab l e 5 -2 is transmitted whenever a ges-
ture is performed on the sensor. This feature can be
enabled via the Gesture Protocol register (Table 5-2).
Gestures are NOT enabled by default.
TABLE 5-1: TOUCH PROTOCOL
Packet Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 1 TOUCHID<3:0> TCH(0) 0 PEN
10 X<6:0>
2000 X<11:7>
30 Y<6:0>
4000 Y<11:7>
Legend: TOUCHID:
PEN:
X:
Y:
TCH:
Touch ID (0-9)
Pen State
0 = Pen Up
1 = Pen Down
X Coordinate of Touch
Y Coordinate of Touch
Always 0, denotes a touch packet
Note: For any “hold” gestures, packets are sent
continuously until the gesture (touch) is
released.