6

AVR32924

32156A-AVR-01/11

4.2 I/O expansion headers

There are four available I/O expansion headers on the kit. Because of the low pin

count on the device, the I/O expansion header pins are shared with onboard

functionality. If “clean” expansion ports are needed, cut-straps are available on some

of the ADC inputs. Otherwise, it is only needed to remove a series resistor to remove

onboard functionality. Table 4-2 show what is shared on the respective header pins.

Table 4-2. UC3 I/O expansion header – J1.

Pin

J1

UC3 pin

Shared with onboard functionality

1

TWI SDA

PA21

Header J4, board controller

2

TWI SCL

PB05

Header J4, board controller

3

UART RX

PB11

Header J4

4

UART TX

PB10

Header J4

5

SPI CS1

PA08

-

6

SPI MOSI

PB03

7

SPI MISO

PB02

Header J4, DataFlash

8

SPI SCK

PB01

Header J4, DataFlash

9

GND

-

-

10

VCC_P3V3

-

-

Table 4-3. UC3 I/O expansion header – J2.

Pin

J2

UC3 pin

Shared with onboard functionality

1

ADC0

(1)

PA14

RC filter output

2

ADC1

(2)

PA15

QMatrix slider X0

3

ADC2

(1)

PA16

Shorted to GND

4

ADC4

(1)

PA18

NTC

5

ADC7

PB07

-

6

ADC8

(2)

PB08

QMatrix slider X3

7

ADC6

PB06

-

8

ADC5

(2)

PB19

QMatrix slider X1

9

GND

-

-

10

VCC_ANA_P3V3

-

-

Notes:

1. ADC channels can be disconnected from onboard functions by cutting the

available cut-straps on the bottom side of the board.

2. ADC channels are shared with the Atmel QMatrix slider. Remove resistors on the

lines to separate the sensors from the ADC.