1.2 KiB
Interrupts
While a great amount of logic can be handled within our code, while loops are not very conducive to event driven
behavior. Enter interrupts. When a change is detected interrupts trigger a handler function.
When an interrupt occurs the processor halts execution of the main program and executes the interrupt handling routine then returns control back to the main program.
On the ESP32 you can use all pins as interrupts with the except of pins 6 - 11.
Basics
Let's use a button and an LED to demonstrate the basics of interrupts.
Your interrupt handler must accept a single parameter, a Pin object, which will be set to the pin triggering the interrupt.
def hangle_interrupt(pin):
pass
Set the GPIO that will be used as the input pin.
pin = Pin(14, Pin.IN)
Attach an interrupt to pin.
pin.irq(trigger=Pin.IRQ_RISING, handler=handle_interrupt)
There are 3 different trigger modes you can use:
- IRQ_RISING - Trigger on the rising edge
- IRQ_FALLING - Trigger on the falling edge. For example when a button is released.
- 3 - Trigger the interrupt on both edges.