Espruino web IDE struggles at discovering custom BLE device and displaying it in the scanned list

[yerpj]

I have ported Espruino on some NICE!NANO boards having a NRF52840 on it. While nRF Connect is totally fine with scanning this board (see screenshots below), Espruino web IDE takes tens of seconds being able to see it and struggles at connecting to it.
I was wondering how Espruino IDE was applying filters while scanning?

[gfwilliams]

The IDE filters devices based on the name and the Nordic UART service in the scan response packet.

Since you've given your device a custom name it's not filtering based on the name, but only on the scan response - which can take a while to work in areas with a lot of BLE signal. You could rename your device "Espruino abcd" and it'd pick up much quicker.

Also - just moving this to the 'other devices' section of the forum

[yerpj]

Got it. It makes sense after all. I will change its name in the python description file. Thank you for your support!

[fanoush]

Maybe the IDE could also filter on manufacturer id which is maybe directly in the advertising packet? Restriction on naming device "Espruino" is not ideal. Also maybe there could be something in IDE settings to show all devices unfiltered?

[gfwilliams]

That's a good idea - I'm very happy to filter on manufacturerData as Espruino has its own now (0x0590). I'm not sure why that didn't happen originally - I think initially it might not have been part of the Web Bluetooth spec so I couldn't do it?

[fanoush]

I'm not sure why that didn't happen

maybe it is not there? just checked from Bangle 2 via

NRF.findDevices(function(devices) {
 console.log(devices);
}, {timeout : 2000, active: false}); 

and got 52840 dongle with Espruino in the middle here

  BluetoothDevice: {
    "id": "57:20:9e:04:2d:c2 private-resolvable",
    "rssi": -80,
    "data": new Uint8Array([2, 1, 26, 26, 255, 76, 0, 12, 14, 8, 62, 25, 236, 80, 7, 55, 149, 174, 104, 82, 162, 58, 51, 16, 5, 75, 28, 4, 233, 20]).buffer,
    "manufacturer": 76,
    "manufacturerData": new Uint8Array([12, 14, 8, 62, 25, 236, 80, 7, 55, 149, 174, 104, 82, 162, 58, 51, 16, 5, 75, 28, 4, 233, 20]).buffer
   },
  BluetoothDevice: {
    "id": "ea:57:0c:57:1f:60 random",
    "rssi": -72,
    "data": new Uint8Array([2, 1, 6, 12, 9, 68, 111, 110, 103, 108, 101, 32, 49, 102, 54, 48]).buffer,
    "name": "Dongle 1f60"
   },
  BluetoothDevice: {
    "id": "23:16:27:7f:5f:a6 private-nonresolvable",
    "rssi": -90,
    "data": new Uint8Array([30, 255, 6, 0, 1, 9, 32, 34, 100, 27, 10, 83, 154, 44, 218, 145, 83, 123, 193, 50, 225, 162, 144, 69, 210, 186, 231, 124, 190, 172, 169]).buffer,
    "manufacturer": 6,
    "manufacturerData": new Uint8Array([1, 9, 32, 34, 100, 27, 10, 83, 154, 44, 218, 145, 83, 123, 193, 50, 225, 162, 144, 69, 210, 186, 231, 124, 190, 172, 169]).buffer
   },

then tried the other way and got Bangle 2 as

  BluetoothDevice: {
    "id": "de:2b:1b:9e:09:cf random",
    "rssi": -74,
    "data": new Uint8Array([2, 1, 6, 15, 9, 66, 97, 110, 103, 108, 101, 46, 106, 115, 32, 48, 57, 99, 102]).buffer,
    "name": "Bangle.js 09cf"
   },

so others have the manufacturer field (and data) there but the dongle has not, so looks we put just the name into advertising packet and manufacturer data is in the scan response too together with service guid, perhaps to allow longer name?

But anyway, if the filter is there in IDE (maybe it even already is?), one could still set custom advertising packet with manufacturer in the advertising packet to solve this issue.

[gfwilliams]

Yes, I don't even put the manufacturer ID in the packet at the moment (or even scan response) - but I guess I could start putting it in by default...

[yerpj]

Well, turns out that it is not working as well as I imagined.
I changed the board file with 'DEFINES+= -DBLUETOOTH_NAME_PREFIX=\'"Espruino"\'',, but it is still very slow at discovering it. On my Android phone, Espruino Web IDE discovers it in a few seconds but on my Windows 10 desktop it still struggles a lot.
Any idea about why the scan procedure may give different results between WIN10 and Android?

[gfwilliams]

I'm afraid I don't, no... You could try some of the Web Bluetooth examples online but I imagine you will find they behave the same as the Web IDE doesn't do anything special.

You could try just restarting the Windows 10 PC and see if that makes any difference?

[fanoush]

Any idea about why the scan procedure may give different results between WIN10 and Android?

I noticed that with some very cheap BT dongles I only see first few (4 or 5?) devices and just changing the dongle in same PC to something better helps. So that is one difference - the hardware in your phone and computer. Second is software - the BT stack itself and the OS too.