Is it possible to connect without using GATT ?

[Roger Clark]

Is it possible to receive connections without setting up a GATT service

For security reasons, I would prefer if generic apps and also the new Web BLE API could make connections to my BLE device.

I would prefer to just advertise a service and handle the connections at a lower level using a custom protocol

Is this possible using S130 SD2.0.1 (SDK 12.0.1) nRF51822 ?

[Petter Myhre]

As far as I know, that is not possible.

I'm not sure what your product is, but maybe you can limit the advertising (and connection requests listening) somehow? Maybe you can activate advertising with a button? Or maybe by movement (if you have an accelerometer)? Maybe you could stop advertising for a certain time if many unwanted devices tries to connect?