using timer with usbd ble uart example

[nikola]

Hello,

I'm using the "usbd ble uart " with twi scanner example to send a sensor value through an arduino 33 ble sense  using nrf52832 and it works very well . but when I want to send the data to android application she stops immediately because the data will be sent  very quickly . So I need to add a timer to this example to send the senor value every second . For this purpose, I copied the content of the "peripheral_timer" example into "usbd ble uart " example. I configure the "sdk_config.h" content accordingly using the timer "1" and the data still send quickly .
there is my code when I use the timer :

  /**
 * @brief Function for main application entry.
 */
   
    advertising_start();

    ret = app_usbd_power_events_enable();

    
    APP_ERROR_CHECK(ret);
   uint32_t time_ms = 1000; //Time(in miliseconds) between consecutive compare events.
    uint32_t time_ticks;
    err_code = NRF_SUCCESS;

    //Configure TIMER_LED for generating simple light effect - leds on board will invert his state one after the other.
    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
    err_code = nrf_drv_timer_init(&TIMER_LED, &timer_cfg, timer_led_event_handler);
    APP_ERROR_CHECK(err_code);

    time_ticks = nrf_drv_timer_ms_to_ticks(&TIMER_LED, time_ms);

    nrf_drv_timer_extended_compare(
         &TIMER_LED, NRF_TIMER_CC_CHANNEL1, time_ticks, NRF_TIMER_SHORT_COMPARE1_CLEAR_MASK, true);

    nrf_drv_timer_enable(&TIMER_LED);      
       
   // Enter main loop
    
    
   for (;;)
    {
       
       while(true)
        
       { 

there is the function of handler timer :

/**
 * @brief Handler for timer events.
 */
void timer_led_event_handler(nrf_timer_event_t event_type, void* p_context)
{
    
    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE1:
            sendcom(result);
            break;

        default:
            //Do nothing.
            break;
    }
}

and there is the function of sending data through the arduino 33 ble sense port :

void sendcom(char  c[]){
         uint8_t length;
         length =strlen(c);
         
         ret_code_t ret = app_usbd_cdc_acm_write(&m_app_cdc_acm,
                                                c  ,
                                                length);

        
        if(ret == NRF_SUCCESS)
        {
           NRF_LOG_RAW_INFO(" %s \n \r ", c);
        }
}

and this is how to use this function in the while true :

 /*************************port activation ********************/
       app_usbd_event_queue_process();
     /*******************************************************************/

     
     itoa(spo2,result,10);
     strcat (result, "\n \r");
     sendcom(  result ); 
     

Please I need your help 

[Einar Thorsrud]

Hi,

the "sdk_config.h" content accordingly using the timer "1" and the data still send quickly

Did you remember to remove the vall to sendcom() in your main loop?

For this purpose, I copied the content of the "peripheral_timer" example into "usbd ble uart " example.

Using a TIMER peripheral should work, but you would be much better off using the timer library (app_timer). This use an RTC so it is low power, and intended for this exact use case. See nRF5 SDK Application Timer Tutorial.

[nikola]

why am I removing this function

Einar Thorsrud said:

Did you remember to remove the vall to sendcom() in your main loop?

I firstly try with this example and it doesn't work 

Einar Thorsrud said:

Using a TIMER peripheral should work, but you would be much better off using the timer library (app_timer). This use an RTC so it is low power, and intended for this exact use case. See nRF5 SDK Application Timer Tutorial.

[nikola]

already app_timer is used to send data through the uart or bleutooth

[nikola]

when I want to test the app_timer function the debugger stops in the lfclk_request function

I have got this error 

[Einar Thorsrud]

nikola said:

why am I removing this function

 I thought the point of all this was to send only every second, is it not? If you continue calling this in your main loop there is not much help in  continuing to do so while also doing it every second. Or did I misunderstand something?

[Einar Thorsrud]

Good, then you know it. It is much better to use this here as well. Having more app_timers is no problem (there is no practical limitation to how many you can have)