err_code = 0x07 after calling a timer start

[Francesca]

Hi, I got an err_code = 0x00000007 after calling this function.

void system_timer_start(void)
{
	uint32_t err_code;

	
	err_code = app_timer_start(m_one_ms_timer_id, ONE_MILLISEC_TICKS, NULL);

	if(err_code != NRF_SUCCESS)
	{
		
	}

	APP_ERROR_CHECK(err_code);
}

m_one_ms_timer_id has been correctly initialized through this function

err_code = app_timer_create(&m_one_ms_timer_id,
		APP_TIMER_MODE_REPEATED,
		one_ms_timeout_handler);
APP_ERROR_CHECK(err_code);

Here, err_code is = 0x00. So, what is the invalid parameter in system_timer_start()? I use sd 130 and nrf51822.

[Jørgen Holmefjord]

What is the value of the parameter ONE_MILLISEC_TICKS? app_timer_start() will return NRF_ERROR_INVALID_PARAM if timeout_ticks is set to less than 5 ticks (APP_TIMER_MIN_TIMEOUT_TICKS).

[Francesca]

Hi, thanks for your answer.

#define APP_TIMER_PRESCALER              0
#define ONE_MILLISEC_TICKS      APP_TIMER_TICKS(1, APP_TIMER_PRESCALER)
#define APP_TIMER_MIN_TIMEOUT_TICKS  60

[Jørgen Holmefjord]

Are you calling it in that order? You should define APP_TIMER_PRESCALER before calling APP_TIMER_TICKS. Also, try printing ONE_MILLISEC_TICKS somewhere, to make sure it is larger than 5.

[Francesca]

Sorry, I edited my answer because I inverted the order of istructions. I declared an extern variable called ticks as follow uint32_t ticks = APP_TIMER_MIN_TIMEOUT_TICKS; Through the debugger, I added ticks to watch 1 and the value displayed is 1984 (0x000007C0).Why? It should be 60.

[Francesca]

I discovered the problem

uint32_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context)
{
    uint32_t timeout_periodic;
    timer_node_t * p_node = (timer_node_t*)timer_id;
    
    // Check state and parameters
    VERIFY_MODULE_INITIALIZED();

    if (timer_id == 0)
    {
        return NRF_ERROR_INVALID_STATE;
    }
    if (timeout_ticks < APP_TIMER_MIN_TIMEOUT_TICKS)
    {
        return NRF_ERROR_INVALID_PARAM;
    }
    if (p_node->p_timeout_handler == NULL)
    {
        return NRF_ERROR_INVALID_STATE;
    }
    
    // Schedule timer start operation
    timeout_periodic = (p_node->mode == APP_TIMER_MODE_REPEATED) ? timeout_ticks : 0;

    return timer_start_op_schedule(user_id_get(),
                                   p_node,
                                   timeout_ticks,
                                   timeout_periodic,
                                   p_context);
}

if (timeout_ticks < APP_TIMER_MIN_TIMEOUT_TICKS) was true because APP_TIMER_MIN_TIMEOUT_TICKS = 60 and ONE_MILLISEC_TICKS = 33. Concerning the 1984, the debugger showed the correct value (60) using optimization 0 ( before I used optimization 3) Why? Thanks for the suggestion!