Detect External Pin Interrupts with nRF51

[rushin]

Hello, I am using external interrupt from an ADXL345 . Can you tell me how to detect that external interrupt with the nRF51 ?

[bjorn-spockeli]

The following code will detect a Low-to-High transition on a given Interrupt Pin( needs to be defined by you).

GPIOTE Event Handler:

void gpiote_evt_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)
{
    switch(action)
    {
        case NRF_GPIOTE_POLARITY_LOTOHI:
            //do something
            break;
        default:
            //do nothing
            break;
    }
}

Main Function:

int main(void)
{
    ret_code_t ret_code;
    
    ret_code = nrf_drv_gpiote_init();
    APP_ERROR_CHECK(ret_code);
    
    nrf_drv_gpiote_in_config_t config =
    {
        .sense = NRF_GPIOTE_POLARITY_LOTOHI,
        .pull = NRF_GPIO_PIN_NOPULL ,
        .is_watcher = false,
        .hi_accuracy = false
    };
        
    
    ret_code = nrf_drv_gpiote_in_init(INTERRUPT_PIN, &config, gpiote_evt_handler);
    APP_ERROR_CHECK(ret_code);
    
    nrf_drv_gpiote_in_event_enable(INTERRUPT_PIN,true);
}

Update:

Project files for an example that toogles a led when a button is pressed

toggle_led_fixed.zip

[rushin]

#include <stdbool.h>

#include <stdint.h>
#include "nrf.h"
#include "nrf_gpiote.h"
#include "nrf_gpio.h"
#include "boards.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "nrf_drv_gpiote.h"
#include "app_error.h"
#define INTERRUPT_PIN   BUTTON_1


void gpiote_evt_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)
{
    switch(action)
    {
        case NRF_GPIOTE_POLARITY_HITOLO:
            //do something
                // LEDS_ON(LED_1);
				//nrf_gpio_pin_toggle(LED_2);
				nrf_drv_gpiote_out_toggle(LED_2);
            break;
        default:
            //do nothing
            break;
    }
}
/**
 * @brief Function for application main entry.
 */
int main(void)
{
     ret_code_t ret_code;
 //LEDS_CONFIGURE(LEDS_MASK);

    ret_code = nrf_drv_gpiote_init();
    APP_ERROR_CHECK(ret_code);
	
//nrf_gpio_cfg_output(LED_2);
//	nrf_gpio_pin_set(LED_2);
	nrf_drv_gpiote_out_config_t led_config = GPIOTE_CONFIG_OUT_TASK_LOW;

ret_code =  nrf_drv_gpiote_out_init(LED_2, &led_config);
APP_ERROR_CHECK(ret_code);
    nrf_drv_gpiote_in_config_t config =
    {
        .sense = NRF_GPIOTE_POLARITY_HITOLO,
        .pull = NRF_GPIO_PIN_PULLUP ,
        .is_watcher = false,
        .hi_accuracy = false
    };


    ret_code = nrf_drv_gpiote_in_init(INTERRUPT_PIN, &config, gpiote_evt_handler);
    APP_ERROR_CHECK(ret_code);

    nrf_drv_gpiote_in_event_enable(INTERRUPT_PIN,true);
}

[rushin]

here when i am pressing button 1, my LED don't turn on

[bjorn-spockeli]

If its a button you have to change NRF_GPIOTE_POLARITY_LOTOHI to NRF_GPIOTE_POLARITY_HITOLO.

[rushin]

i changed it.still its not working