How to implement timer interrupt in nRF9160?

[Yusuke]

Timer interrupt does not work well. In the code below, LED doesn't turn off and "interrupt!" message is not received. I really appreciate it if you give  me any advice.

#include <nrf9160.h>
#include <zephyr.h>
#include <misc/printk.h>
#include <device.h>
#include <nrf_timer.h>
#include <gpio.h>

#define TIEMR_INTERVAL_SEC 5

struct device *dev;

// make 5 sec timer
// f_timer = 16*1000*1000 / (2^PRESCALER)
// sec_interval = (2^PRESCALER) / 16*1000*1000 x NRF_TIMER0_S->CC[0]
void config_timer()
{		
        NRF_TIMER1->TASKS_STOP = 1;
        NRF_TIMER1->MODE = TIMER_MODE_MODE_Timer;
        NRF_TIMER1->TASKS_CLEAR = 1;                             // clear time
        NRF_TIMER1->PRESCALER = 9;                 // value = 0..9
	NRF_TIMER1->BITMODE = TIMER_BITMODE_BITMODE_32Bit;		   //Set counter to 32 bit resolution. MAX count = 2^32-1
	NRF_TIMER1->CC[0] = 156250;  //Set value for TIMER0
        NRF_TIMER1->INTENSET = TIMER_INTENSET_COMPARE1_Enabled << TIMER_INTENSET_COMPARE1_Pos; 
        NVIC_EnableIRQ(TIMER1_IRQn);
        NVIC_SetPriority(TIMER1_IRQn, 0);
}

void TIMER1_IRQHandler(void)
{
	if ((NRF_TIMER1->EVENTS_COMPARE[0] != 0) && ((NRF_TIMER1->INTENSET & TIMER_INTENSET_COMPARE1_Msk) != 0))
        {
                  NRF_TIMER1->EVENTS_COMPARE[0] = 0;           //Clear compare register 0 event	
                  gpio_pin_write(dev, 16, 0);
                  printk("interrupt!\r\n");
        }
}

void main(void)
{
        printk("------------\r\nHello, World!\r\n");
	dev = device_get_binding("GPIO_0");
        gpio_pin_configure(dev, 16, GPIO_DIR_OUT);

        config_timer();
        gpio_pin_write(dev, 16, 1);

        NRF_TIMER1->TASKS_START = 1;
        while(1){
                 printk("Start to sleep\r\n");
                 k_cpu_idle();
                 printk("timer interrupt for %u sec\r\n", TIEMR_INTERVAL_SEC);
        }
}

<>
***** Booting Zephyr OS v1.13.99-ncs2 *****
------------
Hello, World!
Start to sleep
timer interrupt for 5 sec
Start to sleep
// UART communication stops here

[Yusuke]

Thanks a lot! The code below works!

#include <nrf9160.h>
#include <zephyr.h>
#include <misc/printk.h>
#include <device.h>
#include <gpio.h>

#define TIEMR_INTERVAL_SEC 5

struct device *dev;
struct k_timer my_timer;
uint8_t toggle = 0;

void my_expiry_function(struct k_timer *timer_id){
        ++toggle;
        gpio_pin_write(dev, 16, toggle % 2);
        printk("interrupt!\r\n");
}

void main(void)
{
        printk("------------\r\nHello, World!\r\n");
        k_timer_init(&my_timer, my_expiry_function, NULL);

	dev = device_get_binding("GPIO_0");
        gpio_pin_configure(dev, 16, GPIO_DIR_OUT);
        gpio_pin_write(dev, 16, toggle);
        k_timer_start(&my_timer, K_SECONDS(TIEMR_INTERVAL_SEC), K_SECONDS(TIEMR_INTERVAL_SEC));
        
        while(1){
                 printk("Start to sleep\r\n");
                 k_cpu_idle();
                 printk("timer interrupt for %u sec\r\n", TIEMR_INTERVAL_SEC);
        }
}

[Håkon Alseth]

Glad to hear that it worked!

The kernel timers are very handy to use, and only requires a few set of lines to get working properly. However, since they are based on the 32.768 kHz RTC, they're not high speed.

 

Kind regards,

Håkon