Timer not correct？

RE: Timer not correct？

Milk — Wed, 27 Jul 2016 12:22:15 GMT

I changed the APP_TIMER_PRESCALER from 0 to 4.After someday's testing,the clock time is steady,but not always the same.At one morning,I found a device's clock time slowed eight minutes.

RE: Timer not correct？

Ole Bauck — Wed, 20 Jul 2016 08:44:49 GMT

Did you fix it (since you accepted the answer)?

RE: Timer not correct？

Milk — Wed, 20 Jul 2016 06:51:59 GMT

I have created other timers.

void timers_init()
{
 APP_TIMER_INIT(APP_TIMER_PRESCALER,APP_TIMER_MAX_TIMERS,APP_TIMER_OP_QUEUE_SIZE,false);
err_code = app_timer_create(&m_sec_req_timer_id,APP_TIMER_MODE_SINGLE_SHOT,sec_req_timeout_handler);//for ancs

err_code = app_timer_create(&m_clock_timer_id,APP_TIMER_MODE_REPEATED,clock_meas_timeout_handler);//for clock timer ------1s


app_timer_create(&m_acc_timer_id,APP_TIMER_MODE_REPEATED,acc_meas_timeout_handler);//for acc timer------20ms

app_timer_create(&m_pulse_timer_id,APP_TIMER_MODE_REPEATED,pulse_meas_timeout_handler);//for acc timer------25ms

app_timer_create(&m_sec_timer_id,APP_TIMER_MODE_REPEATED,sec_meas_timeout_handler);//for some timer things-----1s

app_timer_create(&m_button_timer_id,APP_TIMER_MODE_REPEATED,button_meas_timeout_handler);//for button events----100ms
}

RE: Timer not correct？

Ole Bauck — Tue, 19 Jul 2016 14:31:09 GMT

I understand that you can't just run the clock timer in a project, I only try to figure out why it does not work.

It may be best if you let me see the code so I can see what is going on and try to reproduce it here. If you don't want to share it on Devzone you can open a case on mypage.

You can use PPI to generate the clock timer, but in combination with the app_timer this will be hard.

RE: Timer not correct？

Milk — Tue, 19 Jul 2016 11:52:48 GMT

I have try with just the clock timer,after one hour,there are no drift.But I can't just run the clock timer in a project.I have a question,how to use ppi to generate the clock timer?

RE: Timer not correct？

Ole Bauck — Tue, 19 Jul 2016 08:18:11 GMT

Can you try with just the clock timer?

After 23 hours I see only 2-3 seconds drift, so still within spec.

RE: Timer not correct？

Milk — Tue, 19 Jul 2016 01:57:19 GMT

Except the clock timer,I have defined other five timers,

#define APP_TIMER_MAX_TIMERS    (6+BSP_APP_TIMERS_NUMBER+2)
#define APP_TIMER_OP_QUEUE_SIZE  (6+BSP_TIMERS_NUMBER+2)
#define APP_TIMER_PRESCALER       4

I have tested the code by using the DK,meanwhile using our custom hardware,the result is the same.

RE: Timer not correct？

Ole Bauck — Mon, 18 Jul 2016 15:39:31 GMT

I have tested for 6 hours now and the drift is under 1 second.

Could you only run the timer code (no BLE or other application code) and see if the timing still is incorrect? Are you using the DK or some custom hardware?

RE: Timer not correct？

Ole Bauck — Fri, 15 Jul 2016 10:29:54 GMT

I don't see the minutes conversion.

I can test it on monday to see if I get the same error.

RE: Timer not correct？

Milk — Fri, 15 Jul 2016 07:01:19 GMT

Hello,Ole Bauck

My Function of clock_process() is:

void clock_timer_process(ClkTime_t *p_time)

{
   p_time -> seconds++;

  if(60<= p_time->seconds)

  {
    p_time->seconds = 0x00;
    p_time->minutes++;
    if(24<= p_time->hour)
    {
      p_time ->hour = 0x00;
      p_tiime ->day++;
      ....
    }
  }


}

RE: Timer not correct？

Ole Bauck — Thu, 14 Jul 2016 13:59:05 GMT

The maximum drift over 12 hours using xtal with 20ppm should be 12x60x60*20/1000000 ~= 1 second, which is way lower than what you measure. You are sure it is not caused by the conversion, for example round off errors, overflow or that you for example count 61 seconds in a minute instead of 60?