4.

Hardware User Guide

4.1.

Connectors

This chapter describes the implementation of the relevant connectors and headers on SAM R21 Xplained

Pro and their connection to the ATSAMR21G18A. The tables of connections in this chapter also

describes which signals are shared between the headers and on-board functionality.

4.1.1.

Xplained Pro Extension Headers

The SAM R21 Xplained Pro headers EXT1 and EXT3 offer access to the I/O of the microcontroller in

order to expand the board e.g. by connecting extensions to the board. These headers all comply with the

standard Xplained Pro extension header specification. All headers have a pitch of 2.54mm.

Table 4-1. Extension Header EXT1

Pin on EXT1

SAM R21 pin Function

Shared functionality

1 [ID]

-

Communication line to ID chip

on extension board

2 [GND]

-

GND

3 [ADC(+)]

PA06

AIN[6]

4 [ADC(-)]

PA07

AIN[7]

5 [GPIO1]

PA13

GPIO

6 [GPIO2]

PA28

GPIO

7 [PWM(+)]

PA18

TCC0 / WO[2]

8 [PWM(-)]

PA19

TCC0 / WO[3]

9 [IRQ/GPIO]

PA22

EXTINT[6]

10 [SPI_SS_B/GPIO]

PA23

GPIO

11 [TWI_SDA]

PA16

SERCOM1 PAD[0] I²C SDA

EXT3 and EDBG

12 [TWI_SCL]

PA17

SERCOM1 PAD[1] I²C SCL

EXT3 and EDBG

13 [USART_RX]

PA05

SERCOM0 PAD[1] UART RX

EDBG

14 [USART_TX]

PA04

SERCOM0 PAD[0] UART TX

EDBG

15 [SPI_SS_A]

PB03

SERCOM5 PAD[1] SPI SS

16 [SPI_MOSI]

PB22

SERCOM5 PAD[2] SPI MOSI

EXT3 and EDBG

17 [SPI_MISO]

PB02

SERCOM5 PAD[0] SPI MISO

EXT3 and EDBG

18 [SPI_SCK]

PB23

SERCOM5 PAD[3] SPI SCK

EXT3 and EDBG

19 [GND]

-

GND

20 [VCC]

-

VCC

Atmel SAM R21 Xplained Pro [USER GUIDE]

Atmel-42243D-SAM-R21-Xplained-Pro_User Guide-04/2016

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