current time gets 0 after connectiong with bluetooth

[Deepak Kumar]

hi, i am using ble_uart example to take time when data arrives and time when data being sent over bluetooth. when i prints the time without connecting to bluetooth. then the time gives a value. but after connecting with bluetooth it gives 0. i dont know what makes it 0.

below is my code:

/**@snippet [Handling the data received over UART] */
void uart_event_handle(app_uart_evt_t * p_event)
{
    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
		uint8_t data[5];
    static uint8_t index,push = 0;
    uint32_t       err_code;
		static uint32_t previous_time,current_time,duration_time,waiting_time;
		waiting_time=450;
		

    switch (p_event->evt_type)
    {
        case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&data_array[index]));
            index++;
						push++;
						if(index%3 == 0)
						{
							count++;
							err_code = app_timer_cnt_get(&current_time);
							APP_ERROR_CHECK(err_code);
							
							err_code = app_timer_cnt_diff_compute(current_time,previous_time,&duration_time);
							APP_ERROR_CHECK(err_code);
							current_time = app_timer_ms(current_time);
							previous_time = app_timer_ms(previous_time);
							duration_time = app_timer_ms(duration_time);
							SEGGER_RTT_printf(0, "current:%d\tprevious:%d\tduration:%d\n",current_time,previous_time,duration_time);
							
							SEGGER_RTT_printf(0, "%x\t%x\t%x\n",data_array[0],data_array[1],data_array[2]);
									sendData(data_array,index);
									previous_time = current_time;
							index = 0;
							preCount=count;
						}						
							
            break;
}

what i am doing wrong here.

thanks!!

[energy]

Hi, I have the same problem using sdk 9.0 and an application based on ble_app_uart. Timer init is identical as ble_app_uart (APP_TIMER_INIT called with same APP_TIMER_.. values)

Call to app_timer_cnt_get() returns a correct value (around 33k tics/per sec) when the softdevice is not connected and returns 0 when softdevice is connected. If I disconect the app_timer_cnt_get() works again

How did you fix this problem ? Thanks

Edit: does app_timer_cnt_get requires to start a timer with timer_start to work ?

[FormerMember]

The app_timer module uses RTC1 and the softdevice uses RTC0, the softdevice should therefore not have any effect of the RTC1 value.

When you are using app_timer with the softdevice, could you try to explicitly start app_timer using app_timer_start(..), and see if that changes anything?

[Mathias]

How can you do that if your not using a self-made timer? I have the same issue but I don't understand why you would have to start a new timer just to read out the RTC1->Counter register?

[FormerMember]

As stated in the "Hardware peripheral" chapter in the Sotfdevice Specification, RTC0 is "blocked" when using the softdevice:

Blocked: 

The hardware peripheral is used by the SoftDevice and is outside the application sandbox.

The application has no access. Interrupts from blocked peripherals are forwarded to the SoftDevice by the MBR and are not available to the application, even inside a Radio Timeslot API timeslot.

[Mathias]

I'm not using RTC0, I'm using RTC1. I don't understand why I need to run a timer, just to ensure the RTC1 is run as well so that I can read the Counter register when needed. I solved it like that now, just by using a repeatable timer that I don't do anything else with. But I still don't understand why I would need that.

[FormerMember]

I don't understand what you mean, could you elaborate a little?

[Mathias]

Well, I have the same problem as the two people above. If use the SoftDevice but don't connect (so just stay advertising), app_timer_cnt_get gives me the current value of the RTC1 Counter register, as expected. But when the advertiser connects with a central and thus becomes a peripheral, app_timer_cnt_get gives 0 constantly.

The app_timer module is used in my application and initializes RTC1 with a prescaler of 0. Above you stated "When you are using app_timer with the softdevice, could you try to explicitly start app_timer using app_timer_start(..), and see if that changes anything?". How can you start the app_timer in general with that method (app_timer_start(..) ) ? From what I see in the infocenter, I can only use this method to start self defined timers that use RTC1 underneath. When I start such a timer (with an empty handler and repeated (not single mode) )  using app_timer_start, after a connection is established, app_timer_cnt_get doesn't give me 0 anymore but gives me seemingly correct counter values. But I don't understand why I need to start an unused timer to get this effect?

[FormerMember]

I see. I had forgotten what this thread was about.

It should not be necessary to to use the app_timer module, what is necessary is to explicitly start RTC1. You should get the same result if you do the following:

NRF_RTC1->TASKS_START = 1;

[Mathias]

Unfortunately, that doesn't seem to be working. If I explicitly start RTC1 using NRF_RTC1->TASKS_START = 1, and don't run the empty, self defined timer anymore, I again get 0 on every request for the RTC1 Counter register's value.

[FormerMember]

Is app_timer used somewhere in your application? I so, your timer and app_timer will share RTC1. In that case, could you try to use RTC2 instead for your timer?