Chromebooks and bluetooth

[FCian]

Hi,

I'm working with a company that is writing an app on both android phones/tablets and chromebooks.  I'm making a new bluetooth device for them, but also helping with their current device to make sure it works with their new app. 

When we scan for devices on an android phone in the nRF Connect app, we see all the devices and see all the advertising packets.  The advertising interval is 50ms which goes down to 200ms after 5 minutes.  The problem is that chromebooks can see the devices for a  short time and then they don't see them again.  Here's what the nRF Chromebook output looks like (attached photo).  The bluetooth devices they are using are old and built on the nRF5 SDK 4.1.  I'm not sure if that is relevant, but it's running an old bluetooth stack.

Any ideas on why the chromebook is having such an issue would be great.

Thank you,

ian

[Simonr]

Hi

Can you share some details on what model of Chromebook this is? The scanning pattern seems to be similar to what you would see with a scanner that does not support scanning on the secondary channels and only scans channels 37, 38 and 39. 

Does the advertising devices have extended advertising enabled by chance? You also say that you're working on nRF5 SDK v4.1. Do you refer to the Bluetooth Mesh or Zigbee SDKs or what, since the nRF5 SDKs for BLE added support for the nRF52 series as of SDK v12.3.0.

It's worth noting that for new projects, the nRF Connect SDK is the recommended SDK to be using.

Best regards,

Simon

[FCian]

Hi Simon,

According to the testing team it is occurring on various kinds of chromebooks.  But the picture is from:

Samsung

Version 132.0.6834.154 (Official Build) (64-bit)

I have an HP I'm using here and will see if I can get you better data.

Yes, you are correct, a little brain have there.  The firmware was built with

nRF5 SDK v11.0.0 (Release data Week 10, 2016)

s132_nrf2_2.0.0_softdevice.hex

Thank you,

ian

[Hieu]

Hi Ian,

Simon is out of office, and I will continue helping you in his stead.

Could you explain a bit more about the graph and the issue? There is a gap between two clusters of lines, and then a similar gap at the end. Does the scanner app just cycle between small intervals of seeing devices and not? How long are such intervals?

What does it look like when you click on a device and go into the "More" screen?

What does it look like on an Android phone, scanning the same environment?

Does this happen only to your customer's devices, or to all BLE devices around?

Regards,

Hieu