Interrupt

The following page provides an example of setting up and triggering an interrupt.

Hardware Setup

For this example to function, connect a wire or resistor between PIN1 and PIN2.

Setup

For this example, we will just import the entire Lumorphix library:

LUA

import("all")

Next we initialise the GPIO:

LUA

reset_all_io_type_cfg()
set_io_type_cfg(PIN1, GPIO_OUT)
set_io_type_cfg(PIN2, GPIO_IN)

Next we reset the interrupt functionality.

LUA

global_interrupt_disable()
set_interrupt_types_for_pin(PIN2, NONE)
ack_interrupt_types_on_pin(PIN2, 0xFF)
    -- NOTE: acknowledge any existing interrupts

Defining an interrupt handler is next.

LUA

function interrupt_handler(interrupt_vector)
    if (interrupt_vector & PIN2_BITMASK) ~= 0 then
        gpio_interrupt_vector = get_interrupts_on_pin(PIN2)
        ack_interrupt_types_on_pin(PIN2, gpio_interrupt_vector)
        if (gpio_interrupt_vector & GPIO_INTRPT_RISING_EDGE) ~= 0 then
            print("\tRising edge!")
        end
        if (gpio_interrupt_vector & GPIO_INTRPT_FALLING_EDGE) ~= 0 then
            print("\tFalling edge!")
       end
    end
end

Binding the defined interrupt handler to the global interrupt source is the next, critical, step.

LUA

interrupt.bind(interrupt_handler)

When you are ready to start triggering interrupts, enable the global interrupt source, and the desired interrupt edge(s).

LUA

global_interrupt_enable()
set_interrupt_types_for_pin(PIN2, GPIO_INTRPT_FALLING_EDGE | GPIO_INTRPT_RISING_EDGE)

Once this is complete, one can trigger some interrupts!

LUA

set_gpio(PIN1, HIGH)
    Rising edge!
set_gpio(PIN1, LOW)
    Falling edge!
set_gpio(PIN1, HIGH)
    Rising edge!
set_gpio(PIN1, LOW)
    Falling edge!

References

API

gpio_interrupt.lua