CC2652R: GapScan is hardly to find all nearby BT devices, how to change configuration/parameter to increase the chance to find all nearby devices?

Hi, 

Thank you for reaching out. 

The results you are describing are for sure not expected. Could you please share more details on the way you run this test? It would be nice if you could specify some elements such as the examples and tools used, the configuration set, the code modifications introduced. 

Best regards, 

We only enable our device to scan BT devices nearby and parse ibeacon broadcaster devices.

We use the following commands and parameters to do BT device scan.

  1. GAP_DeviceInit
  2. GapInit_setPhyParam
     INIT_PHYPARAM_SCAN_INTERVAL
     INIT_PHYPARAM_SCAN_WINDOW
  3. GapScan_enable
     duration
     max number of records
  4. GapScan_disable

There are about 4 BT devices nearby the BT scanner (Our AP).
I found that BT scanner (Our AP) hardly to find all nearby BT devices every time.
Sometimes is 1. Sometimes is 2. .....

How can I adjust the scan parameters to improve the scan performance ?

Are there any other scan commands shall I try to improve that ?

Hello Harrison,

Could you please share your configuration details, such as:

    For peripheral: Primary PHY Interval Minimum/Maximum (ms).
    For central: Scan period, Scan Interval, Scan Window and Scan Duration, Filter Policy?

As a quick example that might be helpful based on the configuration you have. Lets say you have a central that scans for 10 seconds and you have more than two peripherals advertising with an interval of say 4 seconds, then your probability of having the central hitting the channels where the peripheral is advertising is quite low. You could: 1) Increase the advertising interval or 2) Increase the scanning window and interval to increase your probability of getting detecting the peripheral and getting their adv reports.

Hope this helps.

BR,

David.

Currently, I set the following vlaue of parameters :

 1. scan interval         -- new value is 32.   (old value is 16)
 2. scan window           -- new value is 32.   (old value is 16)
 3. duration              -- new value is 1024. (old value is 500)
 4. max number of records -- new value is 512.  (old value is 40)
 5. scan 20 times
 
The scanning results are better than before, and devices with smaller RSSI values ​​can also be scanned.

I'm not sure if this is a reasonable setting and number of scans or not ?
Is there a better way ? So that the scan results can be more stable and without loss.

Hello Harrison,

What is the advertising interval of the peripherals? How many devices are you able to find now? I would like to understand where you currently stand.

BR,

David.