[Android] Trying to scan extended ADV from the Cadence example

[Matthew K]

Hi guys.

With the nRF52840 DK(PCA10056) running the Running Speed and Cadence Service (RSCS) example,
the nRF Connect app on my Galaxy S10/Android 12 was able to scan the "Bluetooth 5 Advertising Extension".

This used the RSCS example and the S132 SoftDevice from SDK 17.1.0.

However, for my custom Android app, calling startLeScan() doesn't show the nRF52 RSCS peripheral when the extended advertising was used.
If the RSCS example is changed to advertise the legacy packets (no extension), my custom Android app can scan the nRF52.

Is there a different method I need to call from Android's BluetoothAdapter?
I hope my custom app can scan nRF52's extended advertisement.

Thanks for your help!

REF URLs:
infocenter.nordicsemi.com/index.jsp

developer.nordicsemi.com/.../README.html

developer.android.com/.../BluetoothAdapter

[Vidar Berg]

Hi,

The API documentation suggests to use startScan API instead: https://developer.android.com/reference/android/bluetooth/le/BluetoothLeScanner#startScan(java.util.List%3Candroid.bluetooth.le.ScanFilter%3E,%20android.bluetooth.le.ScanSettings,%20android.bluetooth.le.ScanCallback). This API supports the  PHY_LE_ALL_SUPPORTED settings option, which I expect will enable extended scanning.

[Matthew K]

Thank you Vidar! I think you meant to use

setScanMode(ScanSettings.PHY_LE_ALL_SUPPORTED)

for the scan settings, right?

Then if I want to set the scanner to have both

PHY_LE_ALL_SUPPORTED and SCAN_MODE_BALANCED

how can I configure both? Is it something like

setScanMode(ScanSettings.PHY_LE_ALL_SUPPORTED + ScanSettings.SCAN_MODE_BALANCED)

? Thanks for your help!

[Simon]

Hello Matthew, 

Sorry for the delay on this, I will be taking over since Vidar is on vacation

I'll get back to you tomorrow

Best regards,

Simon

[Simon]

I talked to a developer internally and got some insight.

Could you try use the following API: https://developer.android.com/reference/android/bluetooth/le/ScanSettings.Builder#setLegacy(boolean), and set legacy to false.

It is by default set to true and extended advertisement is not going to work because of compatibility reasons.

You can also use our library for scanning (wrapper around Android API). Here is a nice example that demostrates how to use this library: https://github.com/NordicSemiconductor/Android-Scanner-Compat-Library#sample

Best regards,

Simon

[Matthew K]

Thank you Simon! I didn't know this GitHub library. This is great for me.

One question from the GitHub library sample:

ScanSettings settings = new ScanSettings.Builder()
				.setLegacy(false)
				.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
				.setReportDelay(5000)
				.setUseHardwareBatchingIfSupported(true)
				.build();

As Vidar has mentioned, when using the library, does this mean 

setScanMode(ScanSettings.PHY_LE_ALL_SUPPORTED)

is not needed?

If ScanSettings.PHY_LE_ALL_SUPPORTED is required, how can I add both

setScanMode(ScanSettings.PHY_LE_ALL_SUPPORTED)

and

setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
?

Thanks for your help!

[Simon]

Yes, setLagacy(false) is needed and setting PHY_LE_ALL_SUPPORTED might be needed to find a device so the best is to set both. For scanner library PHY_LE_ALL_SUPPORTED should be set by default.

Example:

val settings = ScanSettings.Builder()
    .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
    .setPhy(ScanSettings.PHY_LE_ALL_SUPPORTED) //not needed / set by default
    .setLegacy(false)
    .setReportDelay(500)
    .build()

I'm going on vacation for two weeks now, so if you have any follow-up questions could you open a new ticket?

Best regards,

Simon

[Matthew K]

Thank you so much Simon! This last answer solves my ticket.

Have a fun vacation!