Connection loss immediately if timer 2 capture value is changed

[asma]

Hello All ,

I am working on nrf51822 with sdk 7.1.0 and softdevice 7.1.0 .Earlier my ble connection was working very good with no disconnection anytime unless i disconnect it.but now connection is getting lost after 2 to 3 minutes since i have changed the value of NRF_TIMER2->CC[0].

Earlier it was NRF_TIMER2->CC[0] = 62500 and now NRF_TIMER2->CC[0]=625

my timer_init function

void Duration_Timer_Init(void)
{
	
    NRF_TIMER2->MODE            = TIMER_MODE_MODE_Timer;         // Set the timer in Timer Mode
    NRF_TIMER2->TASKS_CLEAR     = 1;                   // clear the task first to be usable for later
	NRF_TIMER2->PRESCALER       =  8;              // Set prescaler. Higher number gives slower timer. Prescaler = 0 gives 16MHz timer
	NRF_TIMER2->BITMODE         = TIMER_BITMODE_BITMODE_16Bit;	 // Set counter to 16 bit resolution
	
	// Enable interrupt on Timer 2 for CC[0] compare match events
	NRF_TIMER2->INTENSET = (TIMER_INTENSET_COMPARE0_Enabled << TIMER_INTENSET_COMPARE0_Pos);
    NVIC_EnableIRQ(TIMER2_IRQn);
}

this initialization was done for 1 sec ,now i want it to be change to 10msec . so i change the value of NRF_TIMER2->CC[0] = 625 .

what could be the reason for the disconnection. is there any relation between stack and timer2?

thanks & Regards Asma

[Petter Myhre]

It could have something to do with the interrupt priorities, please see this.

The default interrupt priority is 0, but when the SoftDevice is enabled the application should use Application High(1) or Application Low(3). Please see Appendix A SoftDevice architecture, Section "Exception (interrupt) management with a SoftDevice" in the S110 SoftDevice specification v2.0.

Try doing a sd_nvic_SetPriority(TIMER2_IRQn, NRF_APP_PRIORITY_LOW); after sd_nvic_EnableIRQ(TIMER2_IRQn);

If it doesn't help please edit your question to include the code where you start the timer, the interrupt request handler.

[asma]

thanks petter and Ulrich for your reply... it was not working with the above solution.. now i just add NVIC_SetPriority(TIMER2_IRQn,NRF_APP_PRIORITY_LOW) after timer interrupt enable and its working.

[Ulrich Myhre]

Please use the sd_nvic_* functions. They validate the inputs you give, disallowing reserved interrupt priorities that could lead to problems like you had :)

[asma]

but when i try with sd_nvic_* functions it is not working properly . it is getting disconnected 5 to 7 minutes every time . with normal function it is working properly .

[Petter Myhre]

Sounds strange. Do you think you can upload your complete project so we can try to reproduce it here?