nRF52 BLE central auto-reconnect to iPhone

RE: nRF52 BLE central auto-reconnect to iPhone

Fred — Tue, 16 Apr 2019 17:33:07 GMT

Ah, I see.

Regarding the point of the iPhone not advertising when it is locked (i.e. the app moved to background processing), I myself only did this for the iPhone being a Central, but this link from Apple explains that this should be possible.

RE: nRF52 BLE central auto-reconnect to iPhone

vincent.golle — Tue, 16 Apr 2019 17:05:15 GMT

Hi,

And thanks !

The iPhone needs to be the peripheral because it contains several 3rd party apps that i want/need to connect to.

Hence I am stuck being the central device

RE: nRF52 BLE central auto-reconnect to iPhone

Fred — Tue, 16 Apr 2019 16:46:41 GMT

Per the BLE specification, a peripheral can only connect when it is 'connectable advertising'. This is because right after sending an advertising it starts the receiver to listen for a response for a possible scanner. This is a really short period. If nothing is received in this period, the peripheral will shut down (after it did the same on the other two advertising channels) and wait for the next advertising interval. So, if the peripheral is not advertising, no connection can be established.

Just out of curiosity: is there a reason why you want the iPhone to be the peripheral? If you make the iPhone the Scanner/Central you can configure it to work even if locked by setting the application to update on the background.