4.2.2 Arduino Connectors

SAMC21N Xplained Pro implements Arduino shield connectors based on the Arduino Uno. All references to Arduino pin names are taken from the official Arduino schematics of the Arduino Uno.

CAUTION: The target section of SAMC21N Xplained Pro can be powered by 3.3V or 5.0V. The maximum voltage the I/O pins can tolerate depends on the supply voltage. Providing higher voltages like 5V to an I/O pin when the ATSAMC21N18A is powered by 3.3V could damage the board.

Info: Note that all pins do not have the exact same functionality as on the Arduino Uno on the shield connectors. Each shield should be checked for compatibility before it is connected.

Table 4-4. J802 - Power
Pin on J802	SAMC21N pin	Arduino pin name	Function	Shared functionality
1	-	RFU	-	-
2	-	IOREF	VCC_TARGET_P3V3_P5V0	-
3	RESETN	RESET	TARGET_RESET	-
4	-	3.3V	VCC_P3V3	-
5	-	5V	VCC_P5V0	-
6	-	GND	GND	-
7	-	GND	GND	-
8	-	VIN	VCC_EXT_P5V0	-

Table 4-5. J803 - Analog
Pin on J803	SAMC21N pin	Arduino pin name	Function	Shared functionality
1	PB09	ADC0	ADC0_AIN3 or SDADC_INP[1] or Y[15]	EXT1
2	PB08	ADC1	ADC0_AIN2 or SDADC_INN[1] or Y[14]	EXT1
3	PC00	ADC2	ADC0_AIN8	-
4	PC01	ADC3	ADC0_AIN9	-
5	PC02	ADC4	ADC0_AIN10	-
6	PC03	ADC5	ADC0_AIN11	-

Table 4-6. J804 - Digital Low
Pin on J804	SAMC21N pin	Arduino pin name	Function	Shared functionality
1	PB25	D0 / RX0	SERCOM0 PAD[1] UART RX	-
2	PB24	D1 / TX0	SERCOM0 PAD[0] UART TX	-
3	PC20	D2	GPIO	-
4	PA14	D3	TC3/WO[0]	Crystal Foot Print
5	PC21	D4	GPIO	-
6	PA15	D5	TC3/WO[1]	Crystal Foot Print
7	PB30	D6	TC0/WO[0]	EXT2
8	PB04	D7	GPIO	-

Table 4-7. J801 - Digital High
Pin on J801	SAMC21N pin	Arduino pin name	Function	Shared functionality
1	PC26	D8	GPIO	-
2	PB31	D9	TC0/WO[1]	EXT2
3	PB18	D10 / SPI-SS	GPIO (SPI SS)	-
4	PC14	D11 / SPI-MOSI	SERCOM7 PAD[2] SPI MOSI	EXT3, EDBG SPI, and Shield2
5	PC12	D12 / SPI-MISO	SERCOM7 PAD[0] SPI MISO	EXT3, EDBG SPI, and Shield2
6	PC11	D13 / SPI-SCK	SERCOM7 PAD[3] SPI SCK	EXT3, EDBG SPI, and Shield2
7	-	GND	-	-
8	PA03	AREF	ADC/VREFA or DAC/VREFB
9	PA16	D14/SDA	SERCOM1 PAD[0] I²C SDA	EXT2, EXT3, Crypto Device, and EDBG I²C
10	PA17	D15/SCL	SERCOM1 PAD[1] I²C SCL	EXT2, EXT3, Crypto Device, and EDBG I²C

Table 4-8. J800 - SPI
Pin on J800	SAMC21N pin	Arduino pin name	Function	Shared functionality
1	PC12	MISO	SERCOM7 PAD[0] SPI MISO	EXT3, EDBG SPI, and Shield
2	-	5V	VCC_TARGET_P3V3_P5V0	-
3	PC11	SCK	SERCOM7 PAD[3] SPI SCK	EXT3, EDBG SPI, and Shield
4	PC14	MOSI	SERCOM7 PAD[2] SPI MOSI	EXT3, EDBG SPI, and Shield
5	RESETN	RESET	TARGET_RESET	-
6	-	GND	GND	-