A pin is the basic object to control I/O pins (also known as GPIO - general-purpose input/output). It has methods to set the mode of the pin (input, output, etc) and methods to get and set the digital logic level. For analog control of a pin, see the ADC class.
from machine import Pin # initialize `P9` in gpio mode and make it an output p_out = Pin('P9', mode=Pin.OUT) p_out.value(1) p_out.value(0) p_out.toggle() p_out(True) # make `P10` an input with the pull-up enabled p_in = Pin('P10', mode=Pin.IN, pull=Pin.PULL_UP) p_in() # get value, 0 or 1
Create a new Pin object associated with the string
id. If additional arguments are given, they are used to initialise the pin. See pin.init()
from machine import Pin p = Pin('P10', mode=Pin.OUT, pull=None, alt=-1)
Initialise the pin:
modecan be one of:
Pin.IN- input pin.
Pin.OUT- output pin in push-pull mode.
Pin.OPEN_DRAIN- input or output pin in open-drain mode.
pullcan be one of:
None- no pull up or down resistor.
Pin.PULL_UP- pull up resistor enabled.
Pin.PULL_DOWN- pull down resistor enabled.
- Pin value:
- Pin value:
altis the id of the alternate function.
Get the pin id.
Get or set the digital logic level of the pin:
- With no argument, return 0 or 1 depending on the logic level of the pin.
- With value given, set the logic level of the pin. value can be anything that converts to a boolean. If it converts to True, the pin is set high, otherwise it is set low.
Pin objects are callable. The call method provides a (fast) shortcut to set and get the value of the pin.
from machine import Pin pin = Pin('P12', mode=Pin.IN, pull=Pin.PULL_UP) pin() # fast method to get the value
pin.value() for more details.
Toggle the value of the pin.
Get or set the pin mode.
Get or set the pin pull.
Get or set the pin hold. You can apply a hold to a pin by passing
True (or clear it by passing
False). When a pin is held, its value cannot be changed by using
Pin.toggle() until the hold is released. This Can be used to retain the pin state through a core reset and system reset triggered by watchdog time-out or Deep-sleep events. Only pins in the RTC power domain can retain their value through deep sleep or reset.
P2, P3, P4, P6, P8, P9, P10, P13, P14, P15, P16, P17, P18, P19, P20, P21, P22, P23
Set a callback to be triggered when the input level at the pin changes.
triggeris the type of event that triggers the callback. Possible values are:
Pin.IRQ_FALLINGinterrupt on falling edge.
Pin.IRQ_RISINGinterrupt on rising edge.
Pin.IRQ_LOW_LEVELinterrupt on low level.
Pin.IRQ_HIGH_LEVELinterrupt on high level.
The values can be OR-ed together, for instance
trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING
handleris the function to be called when the event happens. This function will receive one argument. Set
Noneto disable it.
argis an optional argument to pass to the callback. If left empty or set to
None, the function will receive the Pin object that triggered it.
from machine import Pin def pin_handler(arg): print("got an interrupt in pin %s" % (arg.id())) p_in = Pin('P10', mode=Pin.IN, pull=Pin.PULL_UP) p_in.callback(Pin.IRQ_FALLING | Pin.IRQ_RISING, pin_handler)
For more information on how Pycom’s products handle interrupts, see here.
Contains all Pin objects supported by the expansion board. Examples:
Pin.exp_board.G16 led = Pin(Pin.exp_board.G16, mode=Pin.OUT) Pin.exp_board.G16.id()
Pin objects supported by the module. Examples:
Pin.module.P9 led = Pin(Pin.module.P9, mode=Pin.OUT) Pin.module.P9.id()
The following constants are used to configure the pin objects. Note that not all constants are available on all ports.
- Selects the pin mode:
- Enables the pull up or pull down resistor: