Xplained Pro Extension Headers

The SAM L21 Xplained Pro headers EXT1, EXT2, and EXT3 offers access to the I/O of the microcontroller in order to expand the board e.g., by connecting extensions to the board. These headers are based on the standard extension header specified in Table 1. The headers have a pitch of 2.54mm.

Table 1. Extension Header EXT1
EXT1 pin SAM L21 pin Function Shared functionality
1 [ID] - - Communication line to the ID chip on an extension board
2 [GND] - - Ground
3 [ADC(+)] PB05 AIN[13]  
4 [ADC(-)] PA03 AIN[1]  
5 [GPIO1] PB06 GPIO  
6 [GPIO2] PB07 GPIO  
7 [PWM(+)] PA12 TCC2/WO[0]  
8 [PWM(-)] PA13 TCC2/WO[1]  
9 [IRQ/GPIO] PB04 IRQ4/GPIO  
10 [SPI_SS_B/GPIO] PA02 GPIO SW0
11 [TWI_SDA] PA08 SERCOM2 PAD[0] I²C SDA EXT2, EXT3, and EDBG I²C
12 [TWI_SCL] PA09 SERCOM2 PAD[1] I²C SCL EXT2, EXT3, and EDBG I²C
13 [USART_RX] PB09 SERCOM4 PAD[1] UART RX  
14 [USART_TX] PB08 SERCOM4 PAD[0] UART TX  
15 [SPI_SS_A] PA05 SERCOM0 PAD[1] SPI SS  
16 [SPI_MOSI] PA06 SERCOM0 PAD[2] SPI MOSI  
17 [SPI_MISO] PA04 SERCOM0 PAD[0] SPI MISO  
18 [SPI_SCK] PA07 SERCOM0 PAD[3] SPI SCK  
19 [GND] - - Ground
20 [VCC] - - Power for extension board
Table 2. Extension Header EXT2
EXT2 pin SAM L21 pin Function Shared functionality
1 [ID] - - Communication line to the ID chip on an extension board
2 [GND] - - Ground
3 [ADC(+)] PA10 AIN[18] / PTC_Y8 Onboard QTouch Button 1
4 [ADC(-)] PA11 AIN[19]  
5 [GPIO1] PA20 GPIO EDBG GPIO2
6 [GPIO2] PA21 GPIO EDBG GPIO3
7 [PWM(+)] PB12 TC4/WO[0]  
8 [PWM(-)] PB13 TC4/WO[1]  
9 [IRQ/GPIO] PB14 IRQ14/GPIO  
10 [SPI_SS_B/GPIO] PB15 GPIO  
11 [TWI_SDA] PA08 SERCOM2 PAD[0] I²C SDA EXT1, EXT3, and EDBG I²C
12 [TWI_SCL] PA09 SERCOM2 PAD[1] I²C SCL EXT1, EXT3, and EDBG I²C
13 [USART_RX] PA19 SERCOM1 PAD[3] UART RX EXT3 UART
14 [USART_TX] PA18 SERCOM1 PAD[2] UART TX EXT3 UART
15 [SPI_SS_A] PA17 GPIO  
16 [SPI_MOSI] PB22 SERCOM5 PAD[2] SPI MOSI EXT3 and EDBG SPI
17 [SPI_MISO] PB16 SERCOM5 PAD[0] SPI MISO EXT3 and EDBG SPI
18 [SPI_SCK] PB23 SERCOM5 PAD[3] SPI SCK EXT3 and EDBG SPI
19 [GND] - - Ground
20 [VCC] - - Power for extension board
Table 3. Extension Header EXT3
EXT3 pin SAM L21 pin Function Shared functionality
1 [ID] - - Communication line to the ID chip on an extension board
2 [GND] - - Ground
3 [ADC(+)] PB00 AIN[8]  
4 [ADC(-)] PB01 AIN[9] EDBG GPIO0
5 [GPIO1] PB30 GPIO  
6 [GPIO2] PA15 GPIO  
7 [PWM(+)] PB10 TCC0/WO[4] LED0
8 [PWM(-)] PB11 TCC0/WO[5]  
9 [IRQ/GPIO] PA16 IRQ0/GPIO EDBG GPIO1
10 [SPI_SS_B/GPIO] PA27 GPIO  
11 [TWI_SDA] PA08 SERCOM2 PAD[0] I²C SDA EXT1, EXT2, and EDBG I²C
12 [TWI_SCL] PA09 SERCOM2 PAD[1] I²C SCL EXT1, EXT2, and EDBG I²C
13 [USART_RX] PA19 SERCOM1 PAD[3] UART RX EXT2 UART
14 [USART_TX] PA18 SERCOM1 PAD[2] UART TX EXT2 UART
15 [SPI_SS_A] PB17 SERCOM5 PAD[1] SPI SS  
16 [SPI_MOSI] PB22 SERCOM5 PAD[2] SPI MOSI EXT2 and EDBG SPI
17 [SPI_MISO] PB16 SERCOM5 PAD[0] SPI MISO EXT2 and EDBG SPI
18 [SPI_SCK] PB23 SERCOM5 PAD[3] SPI SCK EXT2 and EDBG SPI
19 [GND] - - Ground
20 [VCC] - - Power for extension board
Parent topic: Connectors