minimum threshold for RSSI?

[sowmya]

Hello,

I am using S110 8.0 stack and 9.0 SDK and I am testing the signal strength. Now I am able to get the BLE_GAP_EVT_RSSI_CHANGED event after I started performing rssi start method using err_code = sd_ble_gap_rssi_start(m_conn_handle, 1, 1);.

But I could not find the documentation to set threshold and skip count. Can anyone tell me how the rssi changes if I keep the skip count very less and what should be the minimum and maximum value to be set for threshold and skip count?

Regards,
Sowmya

[Petter Myhre]

If skip_count is set to 0 and:

threshold_dbm is set to 0 you will get the BLE_GAP_EVT_RSSI_CHANGED after every sample

threshold_dbm is set to to 1 you will get the BLE_GAP_EVT_RSSI_CHANGED event after the sample if the change is +-1 dB or more compared to the sample in the previous BLE_GAP_EVT_RSSI_CHANGED event.

If skip_count is set to 1 and:

threshold_dbm is set to 0 you will get the BLE_GAP_EVT_RSSI_CHANGED after every second sample.

threshold_dbm is set to to 1 you will get the BLE_GAP_EVT_RSSI_CHANGED event if the change is +-1 dB or more on two consecutive samples compared to the sample in the previous BLE_GAP_EVT_RSSI_CHANGED event.

[sowmya]

Thank you Petter for the information. Is there any document for rssi value received wrt dB level. Suppose, if I am getting rssi value 74, what is the db level?