Stop advertising is blocking?

[bart]

I'm trying to regularly change some advertising parameters (ble_gap_adv_params_t.type). The only way i can see to do so, is by stopping and starting advertising. However, I noticed that stopping advertising (sd_ble_gap_adv_stop()) takes about 5-30ms. I didn't expect this call to be blocking and take this long.

Are there any suggestions as to how to update the parameters in a quicker way?

[MartinBL]

How do you measure this? There is not supposed to be any blocking code in sd_ble_gap_adv_stop().

One tip is to use sd_ble_gap_adv_data_set() directly to immediatly set the advertising packet without stopping and starting advertising.

EDIT: I didn't read your question carefully enough. If you change the type parameter from e.g. connectable to unconnectable you cannot use sd_ble_gap_adv_data_set().

But I'm also curious about what advertising interval you use?

[bart]

I added gpio_set and gpio_clear around it, and measured the pin with a logic analyzer. Interval is set to 160 (100ms).

[MartinBL]

I tried it with SDK 11 and S132 v2.0.0 and v2.0.1. The longest execution time I measured was ~55us. The time seems to vary slightly depending on compiler optimization settings and whether the advertising has already been stopped. I got 55us with optimization set to -O0. The code I used was the BLE template example. And I simply added this code in main() right before the main while() loop:

nrf_delay_ms(500);
nrf_gpio_pin_clear(LED_4);
sd_ble_gap_adv_stop();
nrf_gpio_pin_set(LED_4);

Where in your code do you measure the time?

[bart]

Hmm, for me, the function gets executed in an app_sched_execute(), in the main loop. I also measured it like so:

nrf_gpio_pin_set(TEST_PIN);
err_code = sd_ble_gap_adv_stop();
nrf_gpio_pin_clear(TEST_PIN);

Optimization: -Os

A lot of other things are happening too in the meanwhile though, like meshing. I guess I'll try to pinpoint when it takes so long to execute.