ExtInt - External Interrupt

This class configures I/O pins to interrupt when external events occur.

Constructor

machine.ExtInt

class machine.ExtInt(GPIOn, mode, pull, callback)

Parameter:

• GPIOn - Integer type. GPIO pin number to be controlled. See Pin Modules for pin definitions (excluding BG95M3). Click here to view pin correspondences of BG95M3 platform.

• mode - Integer type. Trigger mode.
  IRQ_RISING – Trigger rising edge
  IRQ_FALLING – Trigger falling edge
  IRQ_RISING_FALLING – Trigger rising and falling edge

• pull - Integer type. Pull selection mode.
  PULL_PU – Pull-up mode
  PULL_PD – Pull-down mode
  PULL_DISABLE – Floating mode

• callback - Integer type. The interrupt triggers the callback function.
  A tuple with the length of 2 bytes
  args[0]: GPIO number
  args[1]: Trigger edge (0: rising edge 1: falling edge)

Example:

>>> # Creates an ExtInt object 
>>> from machine import ExtInt
>>> def fun(args):
        print('### interrupt  {} ###'.format(args)) # args[0]: GPIO number args[1]: rising edge or falling edge
>>> extint = ExtInt(ExtInt.GPIO1, ExtInt.IRQ_FALLING, ExtInt.PULL_PU, fun)

Methods

extint.enable

extint.enable()

This method enables interrupts that is to enable external interrupt of an extint object. When the interrupt pin receives the rising edge signal or falling edge signal, it will call a callback function to execute the interrupt.

Return Value:

0 - Successful execution

-1 - Failed execution

extint.disable

extint.disable()

This method disables interrupts associated with extint objects.

Return Value:

0 - Successful execution

-1 - Failed execution

extint.line

extint.line()

This method reads the line number mapped by the pin.

Return Value:

The line number mapped by the pin.

Example:

>>> extint = ExtInt(ExtInt.GPIO1, ExtInt.IRQ_FALLING, ExtInt.PULL_PU, fun)
>>> extint.line()
1

extint.read_count

extint.read_count(is_reset)

This method returns number of times an interrupt was triggered.

Parameter:

• is_reset - Integer type. Whether to reset the count after reading. 0 indicates that the count is not resetted and 1 indicates a count resetting.

Return Value:

The list [rising_count, falling_count]
rising_count: Number of times that the rising edge triggers an interrupt
falling_count: Number of times that the falling edge triggers an interrupt

extint.count_reset

extint.count_reset()

This method clears number of times an interrupt is triggered.

Return Value:

0 - Successful execution

-1 - Failed execution

extint.read_level

extint.read_level()

This method reads the current pin level.

Return Value:

Pin level.

0 - low level.

1 - high level.