Storing adv data

[PKSHER]

Hi. My application is scanning ble beacons for 1 sec every minute, and I want to store this data in an array to be sent every 10 min. I am getting the data in BLE_GAP_EVT_ADV_REPORT in p_ble_evt->header.evt_id, then I am printing to verify what I have received, and then I am storing the data using  the following

for (int i=0;i<p_gap_evt->params.adv_report.data.len;i++)
{
    devices[k++]=p_gap_evt->params.adv_report.data.p_data[i];
}

Then in repeated timer handler, I am sending the devices array that should contain all the beacons 30 byte data. At this time I have 5 beacons, so I declared array of size 200. In timer handler, I am doing this.

static void repeated_timer_handler(void * p_context)
{
    for (int i=0;i<sizeof(devices);i++)
    {
        app_uart_put(devices[i]);
    }
}

My main function looks like

int main(void)
{
    // Initialize.
    log_init();
    uart_init();
    power_management_init();
    ble_stack_init();
    scan_init();
    
    app_timer_init();
    
    create_timers();

    scan_start();

    app_timer_start(m_repeated_timer_id, APP_TIMER_TICKS(15000), NULL);

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}

But I am not getting anything on console, and if change my first snippet like this

for (int i=0;i<p_gap_evt->params.adv_report.data.len;i++)
{
    devices[i]=p_gap_evt->params.adv_report.data.p_data[i];
}

devices [k++] to devices[i], then in timer handler I get data in devices array but the last data that is stored, not all the data. I want to store the data for 10 scanning instances (1 sec scan every 1 min), then the timer handler will be executed every 10 min to send the data, and the process repeats.

Kindly suggest suitable way to achieve this.

I appreciate your suggestions.

Regards,

[Edvin]

Hello,

 

devices [k++] to devices[i], then in timer handler I get data in devices array but the last data that is stored, not all the data

 Does k get incremented every time this handler is called? You can try to print it while you get the data, to see why only the last device is stored, and not all of them.

Is your k variable volatile? Maybe it starts on 0 every time it is called?

[PKSHER]

Hello,

Thanks for you reply. Yes I am able to store data and later in the timer handler, prints the data on console. But the thing is I have not changed anything. Sometimes the data prints, sometimes do not. I do not know what is causing this issue. I was not getting data at first, but when I uploaded the program again, I got the data. Then after letting it run for 1 hour, it stopped the data. Now it is not showing the data. I am not sure if need to post another question for this. I am using nrf52840 dongle. Maybe this was the reason I was not getting the data and I thought that I have done something wrong in my code.

[Edvin]

I really recommend you to use a DK if you do development. Things are a lot easier when you have a debugger so that you can see what's going on, either through debugging or via logging (the USB is not a supported log backend at this point in time). 

The symptoms you describe looks like an APP_ERROR_CHECK(err_code) receiving an err_code != 0, but that can be literally anything. Either some issues with the USB, timers, softdevice, flash, you name it.

[PKSHER]

Yes you are right. I will definitely use DK next time, but I have to complete this project with the dongle. I have already ordered these and the hardware is ready that uses the dongle. So cant change this time.

Well I have checked by making green led on & off when it goes in ble_evt_handler, and blue led when it goes into timer_handler. The code snippet for both are following.

But All I see is green LED is continuously ON, which means it is always in ble_evt_handler, and it is not going into timer_handler, that is why it is not sending any data.

Now, I know the problem. I do not know why is it happening?

static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context) {
  ble_gap_evt_t const *p_gap_evt = &p_ble_evt->evt.gap_evt;
  uint8_t uuid[30];
  uint8_array_t adv_data;

  switch (p_ble_evt->header.evt_id) {
  case BLE_GAP_EVT_ADV_REPORT: {
    nrf_gpio_pin_set(LED2);    //Green LED
    if (p_gap_evt->params.adv_report.data.p_data[0] == 0x02) {
      if (p_gap_evt->params.adv_report.data.p_data[1] == 0x01) {
        if (p_gap_evt->params.adv_report.data.p_data[2] == 0x06) {
            for (int i = 0; i < p_gap_evt->params.adv_report.data.len; i++) 
            {
                devices[deviceLength] = p_gap_evt->params.adv_report.data.p_data[i];
                deviceLength++;
            }
            devices[deviceLength] = p_gap_evt->params.adv_report.rssi;
            deviceLength++;
        }
      }
    }
    nrf_gpio_pin_clear(LED2);
  }
  default:
    break;
  }
}

static void repeated_timer_handler(void *p_context) {
    nrf_gpio_pin_set(LED1);       //BLUE LED
    for (int i = 0; i < sizeof(devices); i++) {
      app_uart_put(devices[i]);
      devices[0] = 0;
      }
      deviceLength = 0;
      nrf_gpio_pin_clear(LED1);
}

[Edvin]

Hello,

I am not saying you can't use the dongle in the product, but you should write your application on a DK, and when everything is working, you can program it on the dongle. Not too late to do this.

If the LED is on, it means that the pin is low/cleared. It is active low. This means that you are not in the BLE_GAP_EVT_ADV_REPORT. You may get the adv reports, but it is difficult to see that the LED turns off for a couple of ms every now and then.