Fast vs Slow advertising, where is the border between?

RE: Fast vs Slow advertising, where is the border between?

awneil — Tue, 23 Apr 2019 17:20:24 GMT

Yes, it does seem that there is nothing specifically fast about "fast advertising", and nothing specifically slow about "slow advertising" - they are just 2 sets of parameters which will be used in turn.

See: https://devzone.nordicsemi.com/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising

So you could actually make the "slow" advertising faster than the "fast" advertising, if you wanted.

I wish Nordic would think more carefully about naming things - so that we don't get these doubts as to whether terms are actually significant or not!

RE: Fast vs Slow advertising, where is the border between?

Valer_I — Mon, 03 Aug 2015 13:46:52 GMT

Thanks! the link was helpful. However I have no possibility to use adv module due to low memory budget. As fas as I understand this module is just CASE that calls sd_ble_gap_adv_start with regard to modes order after BLE_GAP_TIMEOUT_SRC_ADVERTISING received.

RE: Fast vs Slow advertising, where is the border between?

Petter Myhre — Mon, 03 Aug 2015 10:48:06 GMT

I haven't used the advertising module too much, but from the documentation it seems you can just enable fast advertising mode and slow advertising mode like this in advertising_init():

ble_adv_modes_config_t options = {0};
options.ble_adv_fast_enabled = BLE_ADV_FAST_ENABLED;
options.ble_adv_fast_interval = APP_ADV_FAST_INTERVAL;
options.ble_adv_fast_timeout = APP_ADV_FAST_TIMEOUT_IN_SECONDS;

options.ble_adv_slow_enabled = BLE_ADV_SLOW_ENABLED;
options.ble_adv_slow_interval = APP_ADV_SLOW_INTERVAL;
options.ble_adv_slow_timeout = APP_ADV_SLOW_TIMEOUT_IN_SECONDS;

When advertising, the module will pass through the enabled advertising modes until either a connection is made or advertising times out. The flow of advertising is Direct -> Direct Slow -> Fast -> Slow -> Idle. If you start advertising in direct mode, the module first attempts direct advertising. If no information about a previous connection is available or the previous peer is not available, the module attempts fast advertising. If no peer connects before the fast advertising times out, the application moves on to a longer advertising interval, thus slow advertising. If no peer connects before the configured time-out, advertising stops.

Disabled advertising modes are skipped.

So if you only have enabled fast and slow, you will have Fast -> Slow -> Idle.