Техническая Спецификация для Atmel Xplained Pro Evaluation Kit ATSAMD20-XPRO ATSAMD20-XPRO

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ATSAMD20-XPRO
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Atmel | SMART SAM D20 [DATASHEET]
Atmel-42129K–SAM-D20_datasheet–06/2014
31.4
Signal Description
Note:
1.
The number of X and Y lines are device dependent. Refer to 
 for details. 
 for details on the pin mapping for this peripheral. One signal 
can be mapped on several pins. 
31.5
Product Dependencies
In order to use this Peripheral, configure the other components of the system as described in the following sections.
31.5.1 I/O Lines
The I/O lines used for analog X-lines and Y-lines must be connected to external capacitive touch sensor electrodes. 
External components are not required for normal operation. However, to improve the EMC performance, a series resistor 
of 1 K
Ω can be used on X-lines and Y-lines.
Mutual-capacitance Sensor Arrangement
A mutual-capacitance sensor is formed between two I/O lines - an X electrode for transmitting and Y electrode for 
receiving. The mutual capacitance between the X and Y electrode is measured by the Peripheral Touch Controller.
Figure 31-3. Mutual Capacitance Sensor Arrangement
Name
Type
Description
X[n:0]
Digital
X-line (Output)
Y[m:0]
Analog
Y-line (Input/Output)
PTC
Module
MCU
X
0
X
n
Y
0
Y
m
X
1
Y
1
Sensor Capacitance C
x,y
C
x0,y0
C
x0,y1
C
x0,ym
C
x1,y0
C
x1,y1
C
x1,ym
C
xn,y0
C
xn,y1
C
xn,ym
PTC
Module