Invalid arguments in method call for SetDiscoveryFilter with RSSI

[Delapouite]

Hello

I experience a DBusError: Invalid arguments in method call when I try to specify the RSSI threshold in the SetDiscoveryFilter of an adapter:

await adapter.SetDiscoveryFilter({ RSSI: 5 });

The getDiscoveryFilters returns the following array, showing RSSI as a valid filter :
[ 'UUIDs', 'RSSI', 'Pathloss', 'Transport', 'DuplicateData', 'Discoverable', 'Pattern' ]

Is there anything that should be done to pass numbers properly? For example, specifying a boolean filter works as intented:

await adapter.SetDiscoveryFilter({ DuplicateData: true });

Thanks for your help!

[Niels-Be]

So I investigated this and it seams that there is an issue in the dbus library when encoding numbers as variants.
The library always encodes numbers with the smallest possible datatype in this case as BYTE, but bluez expects an INT16 and therefore fails with invalid argument.
This is a major issue also affecting other methods. We probably need to switch to another dbus library since node-dbus no longer seams to be maintained.

[Vishal8523]

Any updates on this one ?

I am trying to set the "adapter.SetDiscoveryFilter({ DuplicateData: true })" yet I am not able to see the devices in the scan.

What should be done ?

@WaeCo : What should be done ?
@Delapouite: Any fix that you have done ?

[Niels-Be]

For anyone interested in this to work. I rewrote the library to use dbus-next which should fix this issue.
You can find the new code in dbus-next branch.

You can now pass along the datatype as Dbus.Variant:

adapter.SetDiscoveryFilter({
        RSSI: new Dbus.Variant("n", -100), // need to use variant to set correct data type
        DuplicateData: true,
});

See: tests/discovery-filter.js for details.

[Haochen7]

Hi @WaeCo, thank you for your work. By the way, is there a plan to migrate the current master to use the dbus-next version of the repo.

Thanks again for your help.

[Niels-Be]

Still waiting on dbusjs/node-dbus-next#67 to be merged.