Example Code for Arduino-Interrupt

Hardware Preparation

• FireBeetle 2 ESP32-E (SKU: DFR0654) ×1
• USB Data Cable ×1

Other Preparation Work

All GPIO pins broken out from the FireBeetle 2 ESP32-E development board, except those that are already occupied or have specific functions, can be used as external interrupt pins.

Enable external interrupt(attachInterrupt(pin，function，mode)), the parameters are as follows:

• pin: the external interrupt pin;

• function: the callback function for the external interrupt;

• mode: 5 external interrupt modes.

• As shown in the table below:

Disable pin interrupt detchInterrupt(pin), no value is returned.

Sample Code

Program function: when the button is pressed, the interrupt is triggered and the serial prints the number of times the button has been pressed.

#include <Arduino.h>

struct Button {         //Define the button struct
    const uint8_t PIN;      //Define button pin
    uint32_t numberKeyPresses;   //Define the number of times the button is pressed.
    bool pressed;        //Determine if the button is pressed, return true if it's pressed
};
Button button = {27, 0, false};  //Instantiated a button, and use the on-board button.

void ARDUINO_ISR_ATTR isr() {    //Interrupt processing function

    button.pressed = true;
}

void setup() {
    Serial.begin(115200);
    pinMode(button.PIN, INPUT_PULLUP);   
    attachInterrupt(button.PIN, isr, FALLING);    //Register the interrupt function, and set the trigger mode to FALLING  
}

void loop() {
    if (button.pressed) {
      button.pressed = false;
      delay(50); 
      if(digitalRead(button.PIN)==LOW){
         button.numberKeyPresses += 1;
         Serial.printf("Button  has been pressed %u times\n", button.numberKeyPresses); //Press the button, and print the total number of times the button has been pressed.   
      }

    }
}

Result

When the program is successfully uploaded, press the on-board button once, the serial port will print a message. The number accumulates every time your press the button, as shown in the figure below.