in nrf52SDK16.0 > ble_central > ble_app_uart_c,
scan filter have 4
1. NRF_BLE_SCAN_NAME_CNT
2. NRF_BLE_SCAN_ADDRESS_CNT
3. NRF_BLE_SCAN_UUID_CNT
4. NRF_BLE_SCAN_APPEARANCE_CNT
if iphone peripheral in foreground, now I can use name or UUID to connect.
I am confusing how to connect iphone in background.
https://stackoverflow.com/questions/39624045/corebluetooth-advertising-in-background-on-ios-10
it says that I can't find device name or UUID when ios in background, so how can I find the iphone?
iphone peripheral in background only have a special 'overflow'.Can nrf52832 find out this when scanning?
Or any other board can do this?
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This isn't anything specific to iOS 10 -- it's always been this way on iOS. On iOS, apps simply cannot send out standard Bluetooth LE advertisements when they are in the background. They have to be in the foreground to do this.
That said, there is limited support in iOS for apps advertising GATT Services in the background. This uses a proprietary technique that only works with other iOS devices that are looking for those services. (Because it uses a non-standard proprietary scheme, the same technique won't work for beacon advertisements, for example.)
Here's how Apple describes it:
...you should be aware that advertising while your app is in the background operates differently than when your app is in the foreground. In particular, when your app is advertising while in the background:
- The CBAdvertisementDataLocalNameKey advertisement key is ignored, and the local name of peripheral is not advertised.
- All service UUIDs contained in the value of the CBAdvertisementDataServiceUUIDsKey advertisement key are placed in a special “overflow” area; they can be discovered only by an iOS device that is explicitly scanning for them.
- If all apps that are advertising are in the background, the frequency at which your peripheral device sends advertising packets may decrease.
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