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37 lines
1.2 KiB
Markdown
37 lines
1.2 KiB
Markdown
5 years ago
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# Interrupts
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While a great amount of logic can be handled within our code, `while` loops are not very conducive to event driven
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behavior. [Enter interrupts](https://randomnerdtutorials.com/micropython-interrupts-esp32-esp8266/). When a change is detected interrupts trigger a handler function.
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When an interrupt occurs the processor halts execution of the main program and executes the interrupt handling routine
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then returns control back to the main program.
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On the ESP32 you can use all pins as interrupts with the except of pins 6 - 11.
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## Basics
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Let's use a button and an LED to demonstrate the basics of interrupts.
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Your interrupt handler must accept a single parameter, a `Pin` object, which will be set to the pin triggering the interrupt.
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````
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def hangle_interrupt(pin):
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pass
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````
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Set the GPIO that will be used as the input pin.
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```
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pin = Pin(14, Pin.IN)
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```
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Attach an interrupt to pin.
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```
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pin.irq(trigger=Pin.IRQ_RISING, handler=handle_interrupt)
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```
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There are 3 different trigger modes you can use:
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* IRQ_RISING - Trigger on the rising edge
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* IRQ_FALLING - Trigger on the falling edge. For example when a button is released.
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* 3 - Trigger the interrupt on both edges.
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