Freertos software timer, RTT logs -> Hard Fault

[D233374]

Hello. 

I am trying to use FreeRTOS and have run into a problem. If I call logging in the FreeRTOS software timer handler, the program stops. 

Here is a simple example:

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_drv_common.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#include "FreeRTOS.h"
#include "timers.h"
#include "task.h"

volatile TimerHandle_t xOneSec_Timer;

void blink_task(void *p){
    
    while(1){
        NRF_LOG_INFO("Blink");
        vTaskDelay(1000);
    }
};

void vOneSecTimer( TimerHandle_t xTimer ){
	configASSERT( xTimer );
	
    NRF_LOG_INFO("Timer");
}

int main(void)
{
    ret_code_t err_code;
    
    // Initialize.
    err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    NRF_LOG_INFO("Start");

    for(uint32_t i=0; i<20; i++){
        NRF_LOG_INFO("Count %d",i);
        for(uint32_t k=0; k<0x100000; k++){__NOP();};
    }
    
    xOneSec_Timer = xTimerCreate( "1STimer", 1000 , pdTRUE, NULL, vOneSecTimer);
    xTimerStart(xOneSec_Timer,0);

    xTaskCreate(blink_task, "Blink", 256, NULL, 2, NULL);
    vTaskStartScheduler();

    while(1);
}

The output to the Ozone terminal looks like this: I see a "Start" message, messages with a counter, but as soon as the timer handler is called, the program stops. If in the timer handler you do not call a log entry, but for example blink the LED, then everything works. I see messages from the blink task and blinking LED.

What am I doing wrong?

[Susheel Nuguru]

You need to initialize your clocks before you use them. 

Use this code snippet instead and test it again on your end.

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_drv_common.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#include "FreeRTOS.h"
#include "timers.h"
#include "task.h"

volatile TimerHandle_t xOneSec_Timer;

void blink_task(void *p){
    
    while(1){
        NRF_LOG_INFO("Blink");
        vTaskDelay(1000);
    }
};

void vOneSecTimer( TimerHandle_t xTimer ){
	configASSERT( xTimer );
	
    NRF_LOG_INFO("Timer");
}

static void clock_init(void)
{
    ret_code_t err_code = nrf_drv_clock_init();
    ASSERT((err_code == NRF_SUCCESS) || (err_code == NRF_ERROR_MODULE_ALREADY_INITIALIZED));

    nrf_drv_clock_hfclk_request(NULL);
    while (!nrf_drv_clock_hfclk_is_running())
    {
        // spin lock
    }

    nrf_drv_clock_lfclk_request(NULL);
    while (!nrf_drv_clock_lfclk_is_running())
    {
        // spin lock
    }
}

int main(void)
{
    ret_code_t err_code;
    
    // Initialize.
    err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    NRF_LOG_INFO("Start");

    clock_init();

    for(uint32_t i=0; i<20; i++){
        NRF_LOG_INFO("Count %d",i);
        for(uint32_t k=0; k<0x100000; k++){__NOP();};
    }
    
    xOneSec_Timer = xTimerCreate( "1STimer", 1000 , pdTRUE, NULL, vOneSecTimer);
    xTimerStart(xOneSec_Timer,0);

    xTaskCreate(blink_task, "Blink", 256, NULL, 2, NULL);
    vTaskStartScheduler();

    while(1);
}

[D233374]

This is a software timer, it works without clocking. If I remove the output to RTT in the timer handler, and make the LED blink, then everything works.

I tried adding clocking on as you suggested, but the problem persists. If there is an output to RTT, the program stops at HF.

[Susheel Nuguru]

Then you and me are seeing two different things. The code I suggested worked fine on an nRF52832 DK with nRF5SDKv17.1.0 on my end.

What is your setup? is it the same as mine?

[D233374]

Yes, it is the same. NRF52832 DK, SDK v17.1, softdevice s132_nrf52_7.2.0

I pushed the entire project on github. github.com/.../nrf52_hf_example

For build, you may need to fix the SDK_ROOT variable in the Makefile.

[Susheel Nuguru]

Can you please fix the access for this? My username is AryanNordic

[D233374]

Sorry for late answer. I don't know why github restrict access. I push this example to another repo https://github.com/Sergey1560/hf_example

How to reproduce the error:

Set SDK_ROOT variable in Makefile

Build firmware -  make

Flash softdevice - make flash_softdevice

Flash firmware - make flash

If line 32 "NRF_LOG_INFO("Timer");" enabled, programm stop in Hard Fault when "vOneSecTimer" has called. 

If you comment out the line 32, everything works.

[Susheel Nuguru]

Sorry for late reply Irek, 

I have the access to the new repo link you sent but I did not manage to look into it today. Sorry for that. I will look into your repo and give you some updates tomorrow. Thanks for your patience so far.