Class pn532::esp32::irq_assert

Class Documentation

class irq_assert

Semaphore-like class which responds to a ESP32 GPIO interrupt. You can invoke operator()() of this class, and the current task will stay suspended until the selected interrupt triggers on the given GPIO. Internally, it uses the ESP32’s interrupt system, so that the CPU is effectively available for other tasks.

Note

This class currently only supports one type of trigger.

Enforced move semantics

irq_assert(irq_assert&&) noexcept
irq_assert &operator=(irq_assert&&) noexcept
irq_assert(irq_assert const&) noexcept = delete
irq_assert &operator=(irq_assert const&) noexcept = delete

Public Functions

irq_assert()

Default constructor: always asserts true when calling operator()().

explicit irq_assert(bool manage_isr_service, gpio_num_t pin, gpio_int_type_t interrupt_type = GPIO_INTR_NEGEDGE)

Constructs a new class that is able to wait for a GPIO interrupt.

Parameters:

  • manage_isr_service – If true, this class will call gpio_install_isr_service and the corresponding gpio_uninstall_isr_service upon construction and destruction, respectively.

  • pin – GPIO pin where to listen for an interrupt.

  • interrupt_type – Type of interrupt to receive, by default negative edge.

gpio_num_t pin() const

The pin on which this instance has set up an interrupt.

Returns:

A pin number or GPIO_NUM_NC, if this instance was default-constructed.

bool operator()(mlab::ms timeout)

Hangs until the interrupt triggers. Waits at most timeout and returns true if and only if pin asserts the interrupt.

Note

Always asserts true if irq_assert was default constructed.

Parameters:

timeout – Maximum timeout before returning false.

Returns:

True if the interrupt specified at runtime has been triggered on the given pin.

~irq_assert()

Releases all resources, and, if specified, calls gpio_uninstall_isr_service.