machine.Pin – Functions to control the nRF GPIO pins

The machine.Pin class contains all of the functions to control the nRF52 GPIO. Import it using

from machine import Pin

To see what’s contained inside the class you can use the help() command

help(Pin)

Constructor

class machine.Pin(pin, mode=IN, pull=PULL_DISABLED, drive=S0S1)

• The S1 Module breaks out two nRF52 GPIO pins. PIN_A1 and PIN_A2. These can be configured as inputs, outputs, interrupts, or ADC inputs (see the ADC class for more info about how to use the pins as ADC inputs)

• To initialize a pin, call the Pin constructor

    myPin = Pin(Pin.PIN_A1, mode=Pin.OUT, pull=Pin.PULL_DISABLED, drive=Pin.S0H1)
  

• To view the current configuration, you can simply print the object

    myPin
    # Will print out the configuration for myPin
    Pin(Pin.PIN_A1, mode=OUT, pull=PULL_DISABLED)
  

• Various options can be provided when setting up the pin

  mode
  IN	Pin will be an input. Default
  OUT	Pin will be an output

  pull
  PULL_DISABLED	Internal pull resistor will be disabled. Default
  PULL_UP	Pin will be pulled up
  PULL_DOWN	Pin will be pulled down

  drive	Drive strength only applicable in output mode
  S0S1	Standard 0, standard 1. Default
  H0S1	High drive 0, standard 1
  S0H1	Standard 0, high drive 1
  H0H1	High drive 0, high drive 1
  D0S1	Disconnect 0, standard drive 1
  D0H1	Disconenct 0, high drive 1
  S0D1	Standard 0, disconnect 1
  H0D1	High drive 0, disconnect 1

Functions

Pin(outputValue)

• Gets or sets the pin value depending on the mode that is configured

    myPin() # Reads the value on the pin
    myPin(True) # Sets the value of the pin if in output mode
  

Pin.irq(callback, trigger=IRQ_TOGGLE)

• Sets up an interrupt for a pin that’s configured as an input. When a trigger is detected, MicroPython will run the callback provided

    # First set up a callback
    def myCallback():
        print("Do stuff")
  
    # Set up a pin as an input
    myPin = Pin(Pin.PIN_A1, mode=Pin.IN, pull=Pin.PULL_DOWN)
  
    # Set up the interrupt
    myPin.irq(myCallback, toggle=Pin.IRQ_RISING)
  

• One of three trigger modes can be selected when configuring an interrupt

  trigger
  IRQ_TOGGLE	Interrupt will detect both rising and falling edges. Default
  IRQ_RISING	Interrupt will only detect rising edges
  IRQ_FALLING	Interrupt will only detect falling edges

Pin.irq_disable()

• Disables any interrupt set up for that pin

    myPin.irq_disable()
  
    ## myCallback will no longer trigger on a rising edge of PIN_A1