带中断的按钮计数器

Question

I want to increment a variable every second when an interrupt is triggered. Code on esp32, esp-idf. I have connected a button, when the button is pressed I want to count the number of seconds.

I did this using polling function, but I want to learn how to do it with interrupt, so counting and polling only when the button is pressed and not checking every second for a button pushed.

#include <stdio.h>
#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"

#define ESP_INTR_FLAG_DEFAULT 0

#define BLINK_LED 13
#define GPIO_INPUT_IO_0 33
int buttonCount = 0;
int i = 0;

SemaphoreHandle_t xSemaphore = NULL;

TaskHandle_t printVariableTask = NULL;

void printVariable(void *pvParameter) {

    int a = (int) pvParameter;
    while (1) {

        printf("A is a: %d \n", a++);
        vTaskDelay(1000 / portTICK_RATE_MS);
    }
}
// interrupt service routine, called when the button is pressed
void IRAM_ATTR button_isr_handler(void* arg) {

    // notify the button task
    xSemaphoreGiveFromISR(xSemaphore, NULL);

}
// task that will react to button clicks
void button_task(void* arg) {

    // infinite loop
    for(;;) {

        // wait for the notification from the ISR
        if(xSemaphoreTake(xSemaphore,portMAX_DELAY) == pdTRUE) {
            int buttonState = gpio_get_level(GPIO_INPUT_IO_0);

            while(buttonState == 1){ //code stucks here!!!!
                buttonCount++;
                printf("GPIO_INPUT_IO_0 %d\n", buttonState);
                printf("Button pressed! %d \n", i++);
                gpio_set_level(BLINK_LED, buttonState);
                vTaskDelay(1000 / portTICK_RATE_MS);
                }
        }
    }
}

void app_main()
{
    // create the binary semaphore
    xSemaphore = xSemaphoreCreateBinary();

    // configure button and led pins as GPIO pins
    gpio_pad_select_gpio(GPIO_INPUT_IO_0);
    gpio_pad_select_gpio(BLINK_LED);

    // set the correct direction
    gpio_set_direction(GPIO_INPUT_IO_0, GPIO_MODE_INPUT);
    gpio_set_direction(BLINK_LED, GPIO_MODE_OUTPUT);

    // enable interrupt on falling (1->0) edge for button pin
    gpio_set_intr_type(GPIO_INPUT_IO_0, GPIO_INTR_POSEDGE);

    // start the task that will handle the button
    xTaskCreate(button_task, "button_task", 2048, NULL, 10, NULL);

    // install ISR service with default configuration
    gpio_install_isr_service(ESP_INTR_FLAG_DEFAULT);

    // attach the interrupt service routine
    gpio_isr_handler_add(GPIO_INPUT_IO_0, button_isr_handler, NULL);

    int pass = 25;
    xTaskCreate(&printVariable, "printVariable", 2048, (void*) pass, 5, &printVariableTask);

}

It works, but when the code enter in the while(buttonState == 1) the loop never ends.

What am I doing wrong?

Answer 1

not sure if this is still and issue for you but try making a new global variable as a flag and set it to 1 in the interrupt routine when you want to start counting. In your loop look for that flag to be set to 1 and start incrementing. When you detect the button is no longer being pressed set the flag to 0.

Also you're never resetting your button state within the button task while loop. That's why your Button State is always coming back as 1.

Actually looking at it further I think you might just need to sample your input level level outside of your if statement within the for(;;) loop. I think this because (I believe) your if in the button task wont be called on a falling edge?