main.c

#define SYS_LOG_LEVEL SYS_LOG_LEVEL_DEBUG
#define SYS_LOG_DOMAIN "main"
#include <logging/sys_log.h>

#include <gpio.h>
#include <kernel.h>
#include <zephyr.h>
#include <nrf.h>
#include <nrf_timer.h>
#include <nrf_ppi.h>
#include <nrf_gpiote.h>
#include <nrf_common.h>

#define GPIO_FREQ 8
#define GPIOTE_CHANNEL 0

#define GPIOTE_IN_CHAN NRF_GPIOTE_INT_IN0_MASK
#define TIMER NRF_TIMER1
#define PPI_CHANNEL NRF_PPI_CHANNEL0
#define TIMER_CC_CHANNEL NRF_TIMER_CC_CHANNEL0
#define TIMER_CAPTURE_CHANNEL NRF_TIMER_TASK_CAPTURE0

void main(void)
{
    struct device *dev = device_get_binding("GPIO_0");

    if (!dev) {
        SYS_LOG_ERR("Couldn't find gpio");
        return;
    }

    /*
    * GPIO Configure and GPIOTE Channel
    */
    gpio_pin_configure(dev, 
                    GPIO_FREQ, 
                    GPIO_DIR_IN | GPIO_PUD_NORMAL);         // Config gpio

    nrf_gpiote_event_configure(GPIOTE_CHANNEL, 
                            GPIO_FREQ, 
                            NRF_GPIOTE_POLARITY_LOTOHI);    // Configure gpiote for pin
    nrf_gpiote_event_enable(GPIOTE_CHANNEL);                // Enable event for gpiote
    // nrf_gpiote_int_enable(GPIOTE_IN_CHAN);                  // Enable interruption for gpiote

    /*
    * Timer Channel
    */
    nrf_timer_frequency_set(TIMER, NRF_TIMER_FREQ_16MHz);   // Set prescale to 16MHz
    nrf_timer_bit_width_set(TIMER, NRF_TIMER_BIT_WIDTH_32); // Set bit mode to 32 bits
    nrf_timer_mode_set(TIMER, NRF_TIMER_MODE_COUNTER);      // Set mode to counter

    /*
    * PPI Channel
    */
    nrf_ppi_channel_enable(PPI_CHANNEL);                        // Enable ppi
    nrf_ppi_channel_endpoint_setup(PPI_CHANNEL, 
                                (u32_t)&NRF_GPIOTE->EVENTS_IN[NRF_GPIOTE_EVENTS_IN_0], 
                                (u32_t)&TIMER->TASKS_COUNT);    // Connect gpiote in event to timer counter

    while (1) {
        // Clears timer count and starts it
        nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_CLEAR);
        nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_START);

        // Wait a second and copy the value to CC channel
        k_sleep(1000);
        nrf_timer_task_trigger(TIMER, TIMER_CAPTURE_CHANNEL);

        // Get the value from CC channel
        uint32_t timer_counter = nrf_timer_cc_read(TIMER, TIMER_CC_CHANNEL);
        SYS_LOG_DBG("Channel counter: %d", timer_counter);

        // Clears timer task capture flag stop and shutdown timer
        TIMER->TASKS_CAPTURE[0] = 0;
        nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_STOP);
        nrf_timer_task_trigger(TIMER, NRF_TIMER_TASK_SHUTDOWN);
    }
}

// uint32_t count = 0;

// static inline void gpio3_int_handler(struct device *port, struct gpio_callback *cb, u32_t pins)
// {
//     count++;
// }

// void main(void)
// {
//     struct device *dev = device_get_binding("GPIO_0");
//     struct gpio_callback rx_tx_cb;

//     gpio_pin_configure(dev, GPIO_FREQ, GPIO_DIR_IN | GPIO_PUD_NORMAL | GPIO_INT | GPIO_INT_EDGE | GPIO_INT_ACTIVE_LOW);

//     gpio_init_callback(&rx_tx_cb, gpio3_int_handler, BIT(GPIO_FREQ));
// 	gpio_add_callback(dev, &rx_tx_cb);
//     gpio_pin_enable_callback(dev, GPIO_FREQ);

//     while (1) {
//         SYS_LOG_DBG("%d", count);
//         k_sleep(1000);
//     }
// }