User manual

Atmel AVR32924: UC3-L0 XPLAINED Hardware User’s Guide [APPLICATION NOTE]
32156C−AVR−06/2013
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5.4 Touch
The UC3-L0 Xplained kit has one QTouch button and one QMatrix slider implemented onboard. The button and the
slider are connected to the built-in CAT module in the AT32UC3L064.
The QMatrix slider can be reconfigured to be used as four separate buttons instead of as a slider.
Table 5-1. UC3-L0 Xplained Touch Connections.
Touch sensor
onboard reference
QTouch method
pin name
QMatrix method
pin name
CAT module pin
name
UC3 pin Selection bit in
PINMODEx register
QSlider X0 X7 CSB6 PA15 SP6
QSlider X1 X10 CSA10 PA19 SP10
QSlider X2 X11 CSB10 PA22 SP10
QSlider X3 X13 CSB12 PB08 SP12
QSlider YK0 YK3 CSB7 PA05 SP7
- Y3 CSA7 PA04 SP7
QButton SNSK0 SNSK15 CSB15 PB09 SP15
- SNS15 CSA15 PB12 SP15
Note: As the device has a very low pin count, a tradeoff has been made to be able to have as many I/O lines as possible
routed to the headers. The sensor lines to the QTouch button and the QMatrix slider are shared with some of the
headers. The sensitivity of the sensor lines is very high on these exposed pins, and so touching the I/O pins will
give erroneous result in the touch sensing mechanism.
Note: Adding top modules to the board with functionality connected to these pins is not recommended. Top modules without
functionality on these pins will only add some capacitive load and will not affect the QMatrix sensor significantly.
5.5 Board Controller
The board controller and the Atmel AT32UC3L064 are connected together through TWI and UART. Both interfaces can
be used to communicate between the devices, but only the UART is implemented by default in the board controller.
Table 5-2. AT32UC3L064 and Board Controller Communication Interface.
Interface Atmel AT32UC3L064 pin Atmel AT32UC3B1256 pin
UART RX
(1)
PA07 PA24
UART TX
(1)
PA06 PA23
TWI SCL PB05 PA09
TWI SDA PA21 PA10
Note: 1. These represent the RX and TX on the device. The RX on one device is connected to TX on the other
device, and vice versa.