Hello,
I've run into a problem, which seems at least to be similar to that described in another thread. In short, if I set up a counter with CC[n] and start it, a COMPARE[n] event will be generated at some point. If in the corresponding handler I reset the counter, the COMPARE[n] event will not be generated any more.
To show what I mean, I added one line (marked by the comment "!!!! THIS IS THE ADDED LINE !!!!") to the RTC example of SDK v14, as shown below.
#include "nrf.h"
#include "nrf_gpio.h"
#include "nrf_drv_rtc.h"
#include "nrf_drv_clock.h"
#include "boards.h"
#include "app_error.h"
#include <stdint.h>
#include <stdbool.h>
#define COMPARE_COUNTERTIME (3UL) /**< Get Compare event COMPARE_TIME seconds after the counter starts from 0. */
#ifdef BSP_LED_0
#define TICK_EVENT_OUTPUT BSP_LED_0 /**< Pin number for indicating tick event. */
#endif
#ifndef TICK_EVENT_OUTPUT
#error "Please indicate output pin"
#endif
#ifdef BSP_LED_1
#define COMPARE_EVENT_OUTPUT BSP_LED_1 /**< Pin number for indicating compare event. */
#endif
#ifndef COMPARE_EVENT_OUTPUT
#error "Please indicate output pin"
#endif
const nrf_drv_rtc_t rtc = NRF_DRV_RTC_INSTANCE(0); /**< Declaring an instance of nrf_drv_rtc for RTC0. */
/** @brief: Function for handling the RTC0 interrupts.
* Triggered on TICK and COMPARE0 match.
*/
static void rtc_handler(nrf_drv_rtc_int_type_t int_type)
{
if (int_type == NRF_DRV_RTC_INT_COMPARE0)
{
nrf_gpio_pin_toggle(COMPARE_EVENT_OUTPUT);
nrf_drv_rtc_counter_clear(&rtc); ///< !!!! THIS IS THE ADDED LINE !!!!
}
else if (int_type == NRF_DRV_RTC_INT_TICK)
{
nrf_gpio_pin_toggle(TICK_EVENT_OUTPUT);
}
}
/** @brief Function configuring gpio for pin toggling.
*/
static void leds_config(void)
{
bsp_board_leds_init();
}
/** @brief Function starting the internal LFCLK XTAL oscillator.
*/
static void lfclk_config(void)
{
ret_code_t err_code = nrf_drv_clock_init();
APP_ERROR_CHECK(err_code);
nrf_drv_clock_lfclk_request(NULL);
}
/** @brief Function initialization and configuration of RTC driver instance.
*/
static void rtc_config(void)
{
uint32_t err_code;
//Initialize RTC instance
nrf_drv_rtc_config_t config = NRF_DRV_RTC_DEFAULT_CONFIG;
config.prescaler = 4095;
err_code = nrf_drv_rtc_init(&rtc, &config, rtc_handler);
APP_ERROR_CHECK(err_code);
//Enable tick event & interrupt
nrf_drv_rtc_tick_enable(&rtc,true);
//Set compare channel to trigger interrupt after COMPARE_COUNTERTIME seconds
err_code = nrf_drv_rtc_cc_set(&rtc,0,COMPARE_COUNTERTIME * 8,true);
APP_ERROR_CHECK(err_code);
//Power on RTC instance
nrf_drv_rtc_enable(&rtc);
}
/**
* @brief Function for application main entry.
*/
int main(void)
{
leds_config();
lfclk_config();
rtc_config();
while (true)
{
__SEV();
__WFE();
__WFE();
}
}
I would expect LED2 to toggle every 3 seconds, but it only turns on once and then stays on. (Tested on PCA10040 V1.1.1 2017.5 and 2016.43)
Is this behavior explainable? Can I at all clear the counter when the RTC is on?
Thanks, Tamas
