AT25DF081-SSH ATMEL [ATMEL Corporation], AT25DF081-SSH Datasheet - Page 8

• Manufacturer Part Number: AT25DF081-SSH
• Description: 32-bit Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

6 Miscellaneous I/O
6.1 Mechanical button
6.2 LEDs
6.3 Analog I/O
6.4 Touch
8
AVR32918
The board is equipped with one mechanical button. Because the button is used to
enter bootloader mode it has a pull-up mounted, this means it is not necessary to use
the pull-up in the UC3 to detect the status of the button.
The Atmel UC3-A3 XPLAINED has four yellow LEDs which are connected to the
Atmel AT32UC3A3256 and all of them are active low.
One dual LED is mounted near the USB connector. It has one green LED which is
used to indicate power and one red LED that can be used for other purposes. The
green LED will be active when power is applied to the board but it can be disabled by
software from the AT32UC3A3256 device if needed. The red LED is active low and
the green LED is active high.
A RC filter and a NTC temperature sensor are connected to ADC0 and ADC1
respectively. These analog sensors are used as input to the ADC but it is also
possible to disconnect them by cutting the cut-straps on the bottom side of the board.
The RC filter (1. order low-pass) has an approximate 3dB cut-off frequency of 159Hz.
The input to the RC filter is one of the UC3 GPIO pins that can be configured to
output a PWM signal to the RC filter. This can be used to generate a DC voltage on
the output of the RC filter which can be measured on the ADC. As this is a 1. order
filter, the ripple on the DC voltage is proportional to the input frequency. A higher
input frequency will give lower ripple on the output.
The UC3-A3 XPLAINED kit has one QTouch button and one QTouch slider; both are
connected to GPIO pins on the AT32UC3A3256.
Table 6-1. UC3 touch connections.
Touch sensor
onboard reference
CH1
CH1
CH2
CH2
CH3
CH3
CH4
CH4
QTouch method pin name
SNSK1
SNS1
SNSK2
SNS2
SNSK3
SNS3
SNSK4
SNS4
UC3 GPIO pin
98
99
100
101
102
103
104
105
32159A-AVR-01/11