SAM C21N Xplained Pro Evaluation Kit

Overview

The SAM C21N Xplained Pro evaluation kit is ideal for evaluation and prototyping with the SAM C21N Cortex®-M0+ processor-based microcontrollers. The kit includes Atmel’s Embedded Debugger (EDBG), which provides a full debug interface without the need for additional hardware.

ATSAMC21N-XPRO

Hardware

  • ATSAMC21N18A ARM Cortex-M0+ processor at 48 MHz

  • 32.768 kHz crystal oscillator

  • 256 KiB flash memory, 32 KiB of RAM, 8KB RRW flash

  • One yellow user LED

  • One mechanical user push button

  • One reset button

  • One QTouch® button

  • On-board USB based EDBG unit with serial console

  • Two CAN transceivers

Supported Features

The atsamc21n_xpro board configuration supports the following hardware features:

Interface

Controller

Driver / Component

NVIC

on-chip

nested vector interrupt controller

Flash

on-chip

Can be used with LittleFS to store files

SYSTICK

on-chip

systick

WDT

on-chip

Watchdog

ADC

on-chip

Analog to Digital Converter

GPIO

on-chip

I/O ports

PWM

on-chip

Pulse Width Modulation

USART

on-chip

Serial ports

I2C

on-chip

I2C ports

SPI

on-chip

Serial Peripheral Interface ports

CAN

on-chip

CAN ports

Other hardware features are not currently supported by Zephyr.

The default configuration can be found in the Kconfig boards/arm/atsamc21n_xpro/atsamc21n_xpro_defconfig.

Pin Mapping

The SAM C21N Xplained Pro evaluation kit has 4 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.

For more details please refer to SAM C21 Family Datasheet [1] and the SAM C21N Xplained Pro Schematic [2].

Default Zephyr Peripheral Mapping:

  • ADC0 : PB09

  • ADC1 : PA08

  • CAN0 TX : PA24

  • CAN0 RX : PA25

  • CAN1 TX : PB14

  • CAN1 RX : PB15

  • SERCOM0 USART TX : PB24

  • SERCOM0 USART RX : PB25

  • SERCOM1 I2C SDA : PA16

  • SERCOM1 I2C SCL : PA17

  • SERCOM2 USART TX : PA12

  • SERCOM2 USART RX : PA13

  • SERCOM4 USART TX : PB10

  • SERCOM4 USART RX : PB11

  • SERCOM5 SPI MISO : PB00

  • SERCOM5 SPI MOSI : PB02

  • SERCOM5 SPI SCK : PB01

  • GPIO/PWM LED0 : PC05

System Clock

The SAMC21 MCU is configured to use the 32.768 kHz internal oscillator with the on-chip internal oscillator generating the 48 MHz system clock.

Serial Port

The SAMC21 MCU has eight SERCOM based USARTs with three configured as USARTs in this BSP. SERCOM4 is the default Zephyr console.

  • SERCOM0 9600 8n1

  • SERCOM2 115200 8n1

  • SERCOM4 115200 8n1 connected to the onboard Atmel Embedded Debugger (EDBG)

PWM

The SAMC21 MCU has 3 TCC based PWM units with up to 4 outputs each and a period of 24 bits or 16 bits. If CONFIG_PWM_SAM0_TCC is enabled then LED0 is driven by TCC2 instead of by GPIO.

Programming and Debugging

The SAM C21N Xplained Pro comes with a Atmel Embedded Debugger (EDBG). This provides a debug interface to the SAMC21 chip and is supported by OpenOCD.

Flashing

  1. Build the Zephyr kernel and the hello_world sample application:

    west build -b atsamc21n_xpro samples/hello_world

  2. Connect the SAM C21N Xplained Pro to your host computer using the USB debug port.

  3. Run your favorite terminal program to listen for output. Under Linux the terminal should be /dev/ttyACM0. For example:

    $ minicom -D /dev/ttyACM0 -o

    The -o option tells minicom not to send the modem initialization string. Connection should be configured as follows:

    • Speed: 115200

    • Data: 8 bits

    • Parity: None

    • Stop bits: 1

  4. To flash an image:

    west build -b atsamc21n_xpro samples/hello_world
west flash

    You should see “Hello World! atsamc21n_xpro” in your terminal.

References