How to make nRF52832 communicate with Movesense device?

[DimitraN]

I would like to create a project that my custom board of nRF52832 will communicate with Movesense device (which also is nRf52832) over BLE, to collect data from the sensors of this device. 

I have downloaded the custom_gattsvc_app with DFU in Movesense, which creates a custom Thermometer Service (uuid 0x1809). It is a sample code the company provides to get familiar with developing a custom gatt service. 

The problem is that when I connect with my phone with nRF Connect App, in the scanning page it says that the Movesense device has "incomplete list of 16-bit UUID: 0xFDF3 and 0x1809" 
What does this mean?

Then, after connection, the 0xFDF3 Service appears, but the 0x1809 the Thermometer one doesn't. 

Any ideas what does that mean and why the app cannot recognise this service? My goal is to test it first with app and then develop code with my custom board as a central that it will connect with Movesense.. 
Any ideas will be very much appreciated. (I have also asked question in stackoverflow, hoping I will get an answer from Movesense too, however I thought I should give it a try here too). 

Thank you

[Sigurd]

Hi!

The problem is that when I connect with my phone with nRF Connect App, in the scanning page it says that the Movesense device has "incompatible list of 16-bit UUID: 0xFDF3 and 0x1809" 
What does this mean?

Could you add a screenshot of how this looks like on the phone?

[DimitraN]

Yes sure, 

this is the message of "incomplete list of uuids" in the scanning page 
and when I connect with the device,

 

The 0xFDF3 Service appears which in my understanding should not, as it is not part of the firmware and the 0x1809 doesn't.

In this link /samples/custom_gattsvc_app/CustomGATTSvcClient.cpp  it shows the service and characteristics.. 

Maybe I have done something wrong, I have no idea, but I thought connecting to the device with nRF Connect would give me some help and understanding on how I will then develop code for the nRf52832 to connect as a central. 

[Sigurd]

Hi!

The Service UUID Advertising Type can contain either full or partial lists of service UUIDs. This allows other devices to understand what services the peripheral device offers without needing to create a connection with it. So "incomplete list of 16-bit UUID: 0xFDF3 and 0x1809" means that the GATT server have 0xFDF3 and 0x1809, but that this list is incomplete, and that it have other services as well.

If you after connection, don't find the 0x1809 service, i.e. Health Thermometer service, then this seems like a bug on the Movesense device. It should either implement this service, or stop advertising that it has it.

[DimitraN]

Ok thank you very much for your insight!

So, one last clarification, this couldn't be caused from your application (nRF Connect) due to any limitations regarding the form of the UUIDs?

Because, on the other example, /samples/gatt_sensordata_app if I download the firmware in Movesense, which also uses gatt service to communicate, 

the screenshots is this:  

The 0xFDF3 remains (the 0x1809 doesn't cause it is not in this example) in the list of incomplete UUIDs, and after connection 

the same characteristcs and services are included. 

But, as the example suggests, when I run index.html in Google Chrome (gatt_sensordata_app/web_client/) my computer connects successfully and discovers the Service "34802252-7185-4d5d-b431-630e7050e8f0" as expected (as I can see in the code of the sample code). 

(code in Google Chrome when I run index.html there).

So, could it be because of any limitation of nRF Connect of the kind of discoverable UUIDs, that it cannot recognise it and not of Movesense? 
Maybe, if this is the case, I should try it directly to connect with my nRF52832 board and give up the idea of testing with nRF Connect.

[Sigurd]

Hi!

DimitraN said:

So, could it be because of any limitation of nRF Connect of the kind of discoverable UUIDs, that it cannot recognise it and not of Movesense? 

I don't think so. But you can try to Refresh services, and see if doing a new service discovery changes anything.

You can also test with the nRF Connect for Desktop Bluetooth Low Energy app

https://www.nordicsemi.com/Products/Development-tools/nRF-Connect-for-Desktop

https://infocenter.nordicsemi.com/topic/ug_nrfconnect_ble/UG/nRF_Connect_BLE/nRF_Connect_Service_discovery.html

[DimitraN]

Thank you very much for your help!
I did refresh Services and indeed the correct Service appeared. 

Unbelievable that this didn't happen during the multiple connections/disconnections I did but thankfully it works.