Adafruit Metro M4 Airlift pin assignment table

Pin GPIO Pin name IRQ ADC ADC Serial Serial TC PWM PWM

2 PA02 A0 2 0 - - - - - -

5 PA05 A1 5 5 - - 0/1 0/1 - -

6 PA06 A2 6 6 - - 0/2 1/0 - -

32 PB00 A3 9 12 - - 5/2 7/0 - -

40 PB08 A4 8 2 0 - 4/0 4/0 - -

41 PB09 A5 9 3 1 - 4/1 4/1 - -

23 PA23 D0 7 - - 3/1 5/0 4/1 1/7 0/3

22 PA22 D1 6 - - 3/0 5/1 4/0 1/6 0/2

49 PB17 D2 1 - - 5/1 - 6/1 3/1 0/5

48 PB16 D3 0 - - 5/0 - 6/0 3/0 0/4

45 PB13 D4 13 - - 4/1 - 4/1 3/1 0/1

46 PB14 D5 14 - - 4/2 - 5/0 4/0 0/2

47 PB15 D6 15 - - 4/3 - 5/1 4/1 0/3

44 PB12 D7 12 - - 4/0 - 4/0 3/0 0/0

21 PA21 D8 5 - - 5/3 3/3 7/1 1/5 0/1

20 PA20 D9 4 - - 5/2 3/2 7/0 1/4 0/0

3 PA03 AREF 3 10 - - - - - -

18 PA18 D10 2 - - 1/2 3/2 3/0 1/2 0/6

19 PA19 D11 3 - - 1/3 3/3 3/1 1/3 0/7

16 PA16 D13 0 - - 1/0 3/1 2/0 1/0 0/4

36 PB04 ESP_BUSY 4 - 6 - - - - -

15 PA15 ESP_CS 15 - - 2/3 4/3 3/1 2/1 1/3

33 PB01 ESP_GPIO0 1 13 - - 5/3 7/1 - -

37 PB05 ESP_RESET 5 - 7 - - - - -

55 PB23 ESP_RTS 7 - - 1/3 5/3 7/1 - -

7 PA07 ESP_RX 7 7 - - 0/3 1/1 - -

4 PA04 ESP_TX 4 4 - - 0/0 0/0 - -

43 PB11 FLASH_CS 12 - - - 4/3 5/1 0/5 1/1

11 PA11 FLASH_HOLD 11 11 - 0/3 2/3 1/1 0/3 1/7

9 PA09 FLASH_MISO 9 9 3 0/1 2/0 0/1 0/1 1/5

8 PA08 FLASH_MOSI - 8 2 0/0 2/1 0/0 0/0 1/4

42 PB10 FLASH_SCK 10 - - - 4/2 5/0 0/4 1/0

10 PA10 FLASH_WP 10 10 - 0/2 2/2 1/0 0/2 1/6

14 PA14 MISO 14 - - 2/2 4/2 3/0 2/0 1/2

12 PA12 MOSI 12 - - 2/0 4/1 2/0 0/6 1/2

54 PB22 NEOPIXEL 22 - - 1/2 5/2 7/0 - -

38 PB06 RXLED 6 - 8 - - - - -

13 PA13 SCK 13 - - 2/1 4/0 2/1 0/7 1/3

35 PB03 SCL 9 15 - - 5/1 6/1 - -

34 PB02 SDA 2 14 - - 5/0 6/0 2/2 -

30 PA30 SWCLK 14 - - 7/2 1/2 6/0 2/0 -

31 PA31 SWDIO 15 - - 7/3 1/3 6/1 2/1 -

62 PB30 SWO 14 - - 7/0 5/1 0/0 4/0 0/6

39 PB07 TXLED 7 - 9 - - - - -

24 PA24 USB_DM 8 - - 3/2 5/2 5/0 2/2 -

25 PA25 USB_DP 9 - - 3/3 5/3 5/1 - -

17 PA17 USB_HOSTEN 1 - - 1/1 3/0 2/1 1/1 0/5

0 PA00 - 0 - - - 1/0 2/0 - -

1 PA01 - 1 - - - 1/1 2/1 - -

27 PA27 - 11 - - - - - - -

63 PB31 - 15 - - 7/1 5/0 0/1 4/1 0/7

For the definition of the table columns see the explanation at the table

for Adafruit ItsyBitsy M4 Express :ref:`samd51_pinout_table`.

The default devices at the board are:

- UART 3 at pins PA23/PA22, labelled D0/D1 resp. RX/TX

- I2C 5 at pins PB02/PB03, labelled SDA/SCL

- SPI 4 at pins PA12/PA14/PA13, labelled MOSI, MISO and SCK

- DAC output on pins PA02 and PA05, labelled A0 and A1