BLE senseing Bluetooth and dBi and using dbi level for functional condition setting

[Gillgen1]

my questions is in relation to BLE and the ability to sense RF at different distances using either dBi or RSSI(rather not use this), is there an accessable dBi signal strength parameter we can access and having BLE take an action on a peripheral with distance factor of 10" has anyone done this? what base code would be needed to find this in BLE softdevice, RSSI is relative (due to manufacturers different begin and end algorythms) does BLE identify a dBi paramater to use to set conditions on ???

[Sigurd]

You will have to use RSSI. In the SoftDevice you have functions like sd_ble_gap_rssi_get(), sd_ble_gap_rssi_start() and sd_ble_gap_rssi_stop() to measure the RSSI. You can read more about these functions here.

RSSI is used in e.g. the "Close Proximity Pairing" functionality in the Gazell library, where the host and device need to be in close proximity to each other to allow pairing. Here a -64dB RSSI threshold on the RX packet power is used to indicate if the device is within <30 cm.

[Gillgen1]

Is the -64dB RSSI threshold on RX packet a minimum of <30 cm or a maximum radius or diameter as these are both different.

[Sigurd]

When the dB is ≈ -64dB the distance between the devices is about 30 cm. So when the dB is -63 or less, indicating <30cm distance, pairing is allowed.