Scanning for RSSI values

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michaelmeng998
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Scanning for RSSI values

Hello!

I have a question concerning using the DA14681 and 14583 dongles to test the capturing of RSSI values. When, I open the putty program to begin logging RSSI values under the ble_central_task program, the values seem to sometimes fluctuate around -120 and stay there in that state.. While in that -120 state, any signal interference (covering the dongle) will not affect the change in RSSI as it continues to fluctuate around -120. Other times, the values are accurate and around the appropriate RSSI value corresponding a certain distance.

I am wondering what issues may be causing the large fluctuation in RSSI?

Thanks,

Michael Meng

Device:
MT_dialog
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Hi michaelmeng998,

Hi michaelmeng998,

I dont quite get the question, you are printing on the 68x side the rssi values that you get from the advertising messages from 583 dongles ?

I dont see how you get -120db as an indication for the receiving signal from an advertising device, are you sure about the values that you are printing ? At least on a BLE device i haven't seen this kind of rssi indication.

Thanks MT_dialog

michaelmeng998
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Hye MT_dialog! Thanks for the

Hey MT_dialog! Thanks for the reply. To clarify, we are trying to get RSSI values through a prebuilt function called ble_gap_conn_rssi_get. The function is defined in ble_gap.c.

MT_dialog
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Hi michaelmeng998,

Hi michaelmeng998,

Are you connected to any device in order to use that function and get proper values ?

Thanks MT_dialog

michaelmeng998
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Hi MT_dialog, I am connected

Hi MT_dialog, I am connected to the 14583.

MT_dialog
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Hi michaelmeng998,

Hi michaelmeng998,

I cant replicate the -120 value on an SDK 1.0.8 with a 583 or any other device, this is obsiously a wrong measurement but in case that there is a sync error between the peripheral and the central the device will report very small RSSI values like -110 since when there is no actual reception at that specific time and the device is receiving noise or nothing at all, so it will report that value that indicates that the last time he tried to listen he didn't hear from the peripheral or the master respectively.

Thanks MT_dialog