User manual

SAM4E-EK User Guide
42067A−SAM4E−01/2013
20
4.3.17 QTouch elements
QTouch keys consist in a series of sensors formed by the association of a copper area and the capacitive effect of
human fingers approaching it.
Keys
The Atmel SAM4E-EK implements two individual capacitive touch keys (RIGHT, LEFT).
Slider
A group of channels forms a Slider. A Slider is composed of eight channels for a QTouch acquisition method. Such a
sensor is used to detect a linear finger displacement on a sensitive area. A typical implementation is volume control.
Figure 4-19. QT_Slider.
R122
2.2K
R123
2.2K
Qtouch
R114 1K
C89
100nF
C91 4.7nF
R115 1K
R116 1K
PE4
QKEY
K2
12
R118 1K
R119 1K
R120 1K
R121 1K
PA4
MN17
AT42QT2160
VDD
3
VDD
16
VDD
17
RST
25
SDA
23
SCL
24
CHANGE
7
I2C_A0
21
I2C_A1
22
VREF
8
VSS
4
VSS
18
X0
10
X1
11
X2
12
X3
13
X4
14
X5
15
X6
5
X7
6
GPIO2
1
GPIO3
2
GPIO1
28
Y1A
27
Y1B
20
Y0A
26
Y0B
19
SMP
9
PAD
29
QKEY
K1
12
+3V3
R128 1K
R127 1K
FB3
BN03K314S300R
R124
10K
Slider
S1
X6
X5
X4
X3
X2
X1
X0
Y0
+3V3
C88
1uF
C87
100nF
C90 4.7nF
R129
1M
R117 10K
R130
1M
PA3
4.3.18 LEDs
There are three LEDs on the SAM4E-EK board:
• A blue LED (D2), amber LED (D3) and a green LED (D4), which are user defined and controlled by the GPIO
• A red LED (D5), which is a power LED indicating that the 3.3V power rail is active. It is also controlled by the
GPIO and can be treated as a user LED as well. The only difference with the two others is that it is controlled
through a MOS transistor. By default, the PIO line is disabled; a pull-up resistor controls the MOS to light the
LED when the power is ON
Figure 4-20. LEDs.
PWM
PD20
+3V3
PD21
D4 LED Green
D5 LED Red
R157
470R
R158
470R
R160
470R
R159 100K
D3 LED Amber
Q1IRLML2502
1
32
LEDS
PD22
PWM
POWER
PA0
R154
470R
D2 LED Blue
TIMER