Advanced advertising mode

[hathach]

https://developer.apple.com/library/content/qa/qa1931/_index.html

For discovering your accessory successfully

You must follow the general advertising guidelines in the Bluetooth Accessory Design Guidelines for Apple Products when constructing your advertising packets. A common mistake is to use improper advertising intervals, either due to misconfiguration or in order to save battery usage on the peripheral. Improper intervals are the most common reasons for your app to not be able to discover your accessory in the field, even though you may have observed discovery working properly in your tests.

The advertising interval of your peripheral affects the time to discovery and connect performance. Outside of ideal conditions, for example when your app is no longer active in the foreground, the time to discovery becomes longer. To maximize the probability of being discovered, the accessory must advertise at one of the listed intervals exactly.

The recommended advertising pattern and advertising intervals are:

• First, advertise at 20 ms intervals for at least 30 seconds
• If not discovered after 30 seconds, you may change to one of the following longer intervals: 152.5 ms, 211.25 ms, 318.75 ms, 417.5 ms, 546.25 ms, 760 ms, 852.5 ms, 1022.5 ms, 1285 ms

Important: These specific intervals are the ones to be used exactly! Even the slightest deviation from these actual intervals may dramatically increase your time to discovery.

Note: The above advertising intervals are only for non iBeacon BLE peripherals. For iBeacon advertising, you must follow the iBeacon Specifications, which you can find in the iBeacon for Developers page