NRF52 interrupt logic level event handler

Question

Hello, 
 I am doing a project on a NRF52DK, using SDK15 and SES. 
 I have been trying to implement a basic feature, which will be a part of a bigger system: 
 
 Detect interrupt from sensor (HIGH or LOW) 
 When HIGH:
 
 //do something

When LOW
 
 //do something else

How should I do it? I have been looking into examples such as pin_change_int, gpiote, simple_timer and bsp but have not gotten them to work on both states, only on state change, using the bsp_init() or GPIOE. 
 I think that the function I should be looking into is " bsp_event_to_button_action_assign() " from " bsp.c " but due to my inexperience, I have not figured out how. 
 I could compile: 
 err_code = bsp_event_to_button_action_assign(2, BSP_BUTTON_ACTION_LONG_PUSH, BSP_EVENT_KEY_2_ACTIVE); APP_ERROR_CHECK(err_code); 
 ... where 2 is just the GPIO pin where the interrupt would happen, long push would be the action and BSP_EVENT_KEY_2_ACTIVE is my added special event at bsp_event_t type definition but I have not figured out how to make a function like that in my main.c. 
 Ideally I would like to have a function, which uses a switch statement on events (yes, just like bsp_event_handler ) but according to my own rules, without modifying the libraries - instead of using them. 
 I have found a lot of useful links but basically all of them are for SDK11, which is very frustrating as version 15 is pretty different and I would like to make this project on the latest version. 
 I apologize for the confusion. I have just started with nRF development and I am coming from Arduino platform. If you have any suggestions or would like more information, then let me know and I can try them out and post the output. If I am on the wrong track or you have any useful links for SDK 15, then let me know.

Edvin · Accepted Answer

Hello, 
 If I understand you correctly, you want an interrupt whenever a pin changes state, and you want to do an action depending on what state the pin is in. 
 so something like: 
 pin_interrupt_callback()
{
 if (pin_is_pressed)
 {
 //do something
 }
 else if(pin_is_not_pressed)
 {
 //do something else
 }
} 
 Is that correct? 
 
 A very simple approach is using the pin_int_change example, and adding something in the handler to read the state of the pin. You can e.g. use nrf_gpio_pin_read(uint32_t pin_number); 
 
 If you take the SDK15\examples\peripheral\pin_int_change, and replace the main file with the attached main file, it should toggle one of the LEDs when you push the button down, and another when you release it.

Fullscreen 
 main.c 
 Download 
 
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/** @file
 * @defgroup pin_change_int_example_main main.c
 * @{
 * @ingroup pin_change_int_example
 * @brief Pin Change Interrupt Example Application main file.
 *
 * This file contains the source code for a sample application using interrupts triggered by GPIO pins.
 *
 */

#include <stdbool.h>
#include "nrf.h"
#include "nrf_drv_gpiote.h"
#include "app_error.h"
#include "boards.h"

#ifdef BSP_BUTTON_0
 #define PIN_IN BSP_BUTTON_0
#endif
#ifndef PIN_IN
 #error "Please indicate input pin"
#endif

#ifdef BSP_LED_0
 #define PIN_OUT_1 BSP_LED_0
#endif
#ifdef BSP_LED_1
 #define PIN_OUT_2 BSP_LED_1
#endif
#ifndef PIN_OUT_1
 #error "Please indicate output pin 1"
#endif
#ifndef PIN_OUT_2
 #error "Please indicate output pin 2"
#endif


void in_pin_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)
{
 if(nrf_gpio_pin_read(pin))
 {
 nrf_drv_gpiote_out_toggle(PIN_OUT_1);
 }
 else
 {
 nrf_drv_gpiote_out_toggle(PIN_OUT_2);
 }
}
/**
 * @brief Function for configuring: PIN_IN pin for input, PIN_OUT pin for output,
 * and configures GPIOTE to give an interrupt on pin change.
 */
static void gpio_init(void)
{
 ret_code_t err_code;

 err_code = nrf_drv_gpiote_init();
 APP_ERROR_CHECK(err_code);

 nrf_drv_gpiote_out_config_t out_config = GPIOTE_CONFIG_OUT_SIMPLE(false);

 err_code = nrf_drv_gpiote_out_init(PIN_OUT_1, &out_config);
 APP_ERROR_CHECK(err_code);
 err_code = nrf_drv_gpiote_out_init(PIN_OUT_2, &out_config);
 APP_ERROR_CHECK(err_code);

 nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_TOGGLE(true);
 in_config.pull = NRF_GPIO_PIN_PULLUP;

 err_code = nrf_drv_gpiote_in_init(PIN_IN, &in_config, in_pin_handler);
 APP_ERROR_CHECK(err_code);

 nrf_drv_gpiote_in_event_enable(PIN_IN, true);
}

/**
 * @brief Function for application main entry.
 */
int main(void)
{
 gpio_init();

 while (true)
 {
 // Do nothing.
 }
}


/** @} */

Best regards, 
 Edvinn

NRF52 interrupt logic level event handler

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