.. _pins_zephyr:

GPIO Pins

Use :ref:machine.Pin <machine.Pin> to control I/O pins.

For Zephyr, pins are initialized using a tuple of port and pin number (\"GPIO_x\", pin#) for the id value. For example to initialize a pin for the red LED on a FRDM-k64 board::

    LED = Pin(("GPIO_1", 22), Pin.OUT)

Reference your board's datasheet or Zephyr documentation for pin numbers, see below for more examples.

.. list-table:: Pin Formatting :header-rows: 1

• • Board
  • Pin
  • Format
• • frdm_k64f
  • Red LED = PTB22
  • ("GPIO_1", 22)
• • 96b_carbon
  • LED1 = PD2
  • ("GPIOD", 2)
• • mimxrt685_evk_cm33
  • Green LED = PIO0_14
  • ("GPIO0", 14)

Interrupts

The Zephyr port also supports interrupt handling for Pins using machine.Pin.irq() <machine.Pin.irq>. To respond to Pin change IRQs run::

from machine import Pin

SW2 = Pin(("GPIO_2", 6), Pin.IN)            # create Pin object for switch 2
SW3 = Pin(("GPIO_0", 4), Pin.IN)            # create Pin object for switch 3

SW2.irq(lambda t: print("SW2 changed"))     # print message when SW2 state is changed (triggers change IRQ)
SW3.irq(lambda t: print("SW3 changed"))     # print message when SW3 state is changed (triggers change IRQ)

while True:                                 # wait
    pass