Datasheet

 2012 Microchip Technology Inc. DS41663A-page 7
MTCH6301 PROJECTED CAPACITIVE TOUCH CONTROLLER
.
4.3.2 UNUSED RX/TX PINS
Unused RX/TX pins are driven to Vss automatically,
and should be left as no connects.
4.3.3 RX/TX SCALING COEFFICIENTS
Scaling coefficient registers exist in RAM for each axis
(RX/TX) and must be modified in accordance with the
number of channels that are in use. Special attention
must be paid to sensor dimensions that have fewer
than 5 channels, which will have a smaller maximum
touch output value (coordinate).
The relationship between these constant, as well as the
maximum coordinates that will be transmitted are
displayed in Ta ble 4-2 .
4.3.4 SENSOR ORIENTATION
The final output orientation is configured via the
FLIPSTATE register. This register can be adjusted dur-
ing operation for applications where rotation occurs
during use.
Figure 4-2 shows the initial upright orientation
FLIPSTATE register values for all possible sensor
layouts.
TABLE 4-1: PIN MAP ID CHART
Pin
Map ID
(TX)
Map ID
(RX)
RX0 27 8
RX1 26 7
RX2 25 6
RX3 12 5
RX4 11 4
RX5 10 3
RX6 9 2
RX7 1 1
RX8 0 0
RX9 24 9
RX10 23 10
RX11 22 11
RX12 21 12
TX0 13
—
TX1 6
—
TX2 3 —
TX3 2 —
TX4 4
—
TX5 7 —
TX6 28 —
TX7 29
—
TX8 30 —
TX9 14 —
TX10 15
—
TX11 16 —
TX12 5 —
TX13 8
—
TX14 34
—
TX15 33
—
TX16 32
—
TX17 31 —
Note: Trace routing for sensors requires proper
design technique. Please refer to the
mTouch Sensing Solution design center at
www.microchip.com/mtouch for additional
information on correctly routing touch
sensor traces.
TABLE 4-2: RX/TX SCALING
COEFFICIENTS
Number of
Channels
RX/TX
Scaling
Coefficient
Controller
Output Range
3
65535
[0-2047]
4 [0-3071]
5
[0-4095]
6 52429
7 43691
8 37449
9 32768
10 29127
11 26214
12 23831
13 21845
14 20165
15 18725
16 17476
17 16384
18 15420