Long Press Button Interrupt in NCS

Question

Hi, I am working on long press button interrupt in nrf52832 device & used NCS. I am unable to detect the long press from button.below is my functionality which is I am trying to implement. 
 press for 10 sec after that call a callback function. 
 void long_button_pressed(const struct device *dev, struct gpio_callback *cb, uint32_t pins)
{
 // if (gpio_pin_get_dt(&button_0)) {
 if(pins & BIT(button_0.pin)){
 LOG_INF("button pin detected");
 k_timer_start(&button_timer, K_SECONDS(10), K_NO_WAIT);
 } else {
 LOG_INF("long_press not detected");
 k_timer_stop(&button_timer);
 long_press_detected = false; // Reset flag if button is released
 }
}

void button_timer_expiry_handler(struct k_timer *timer_id)
{
 printk("Button long-pressed for 10 seconds
");
 long_press_detected = true;
 Reset_Flag=1;
 eeprom_write(i2c_dev,EEPROM_RESET_FLAG_ADDRESS, &Reset_Flag, 1);
 eeprom_write(i2c_dev,EEPROM_RESET_TIME_FLAG, &current_epoch_time, 4);
 guide_flag=1;
 eeprom_write(i2c_dev,EEPROM_DEVICE_GUIDE_ADDRESS,&guide_flag,1);
 reset_hardware_locally();
 //reset_hardware();
 k_msleep(1000);
 NVIC_SystemReset();
 // Add your action here
}

void long_press_button(){
 if (!device_is_ready(button_0.port)) {
 printk("Button device not ready
");
 return;
 }
 gpio_init_callback(&button_cb_data,long_button_pressed, BIT(button_0.pin));
 gpio_add_callback(button_0.port, &button_cb_data);

k_timer_init(&button_timer, button_timer_expiry_handler, NULL);

} 
 above is the code of long press button. Pin configuration :- 
 
 gpio_pin_configure_dt ( & button_0 , GPIO_INPUT );

gpio_pin_interrupt_configure_dt ( & button_0 , GPIO_INT_EDGE_BOTH ); 
 
 configuration in overlay file:-

button0 
 { 
 gpios = < & gpio0 21 GPIO_ACTIVE_LOW >; 
 label = "SW1" ; 
 }; 
 
 Suggest a solution how can implement long press button interrupt in zephyr ncs.

Edvin · Accepted Answer

Thank you. I believe my behavior was a bit different than yours, but we are running this on different hardware, so that may be why.

In my case, I was not able to trigger the interrupt, because I shorted the pin to a button pin, and your button_0 devicetree configuration didn't have a pullup. So first, I added this in your test.overlay:

    buttons {
        compatible = "gpio-keys";
        button0
        {
            gpios = <&gpio0 21 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
            label = "SW1";
        };
    };  
};

Then I changed your bsp_button_init() to trigger on both rising and falling edges (like you originally had when you created this ticket):

void bsp_button_init(){

    uint8_t ret;

    if(!device_is_ready(button_0.port)){
        LOG_INF("button init failed");
    }

    // configure button gpio as input
    ret = gpio_pin_configure_dt(&button_0, GPIO_INPUT);
    if (ret < 0) {
        return;
    }
    //ret = gpio_pin_interrupt_configure_dt(&button_0, GPIO_INT_EDGE_RISING);
    ret = gpio_pin_interrupt_configure_dt(&button_0, GPIO_INT_EDGE_BOTH);
    if (ret < 0) {
        return;
    }

}

And finally, I adjusted your long_button_pressed() callback to check the state of the pin, starting the timer only if it was pressed, and stopping the timer if it was not pressed (which would have been triggered by a release action):

void long_button_pressed(const struct device *dev, struct gpio_callback *cb, uint32_t pins)
{
   // if (gpio_pin_get_dt(&button_0)) {
    if(pins & BIT(button_0.pin)){
        int val = gpio_pin_get_dt(&button_0);
        LOG_INF("button pin detected %08x, val %d", pins, val);
        if (val == 1) { // if (val) { 
            k_timer_start(&button_timer, K_SECONDS(10), K_NO_WAIT);
            LOG_INF("Timer started");
        }
        else {
            k_timer_stop(&button_timer);
            long_press_detected = false;
            LOG_INF("Timer stopped");
        }
    }
}

Also added some logging in that callback, as you can see.

Please note:

For testing this is of course ok, but for HW specific .overlays, the "best practice" is to create a folder called boards in your application root folder, and then create an overlay file called "<board_name>.overlay" in there. This will automatically be picked up by the compiler.

For application specific overlays, the common practise is to have a file called "app.overlay". This should hold the devicetree configurations that are common for all boards. I'll add an empty nrf52840dk_nrf52840.overlay in a boards folder, just so that you see what I mean. But this is just formalities, and the way we do it in our samples. You decide how to build up your app.

long_press_v2.zip

Give it a go, and let me know if it doesn't work.

Best regards,

Edvin

Long Press Button Interrupt in NCS

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