Any rules or constraints for using BLE Char elements?


#1

I’m trying to clean up my application for the Hackster Rapid IoT contest and I encountered an odd but reproducible problem. I added a couple of BLE GATT Characteristic Elements and I could no longer provision the device. I get a “Device registration information not valid” error. If I reduce the number of BLE Char elements to ten (10) then provisioning works. If I add another element then I will get the failure . I have seen other programs (OOB Demo) that use many more than 10 BLE Char elements so I’m not sure what’s going on.

I just tried a simple test case, maybe there is a reason that it is not valid but it has repeatable results. I created a project with only BLE Char elements. I can connect and provision my device with 1-6 elements. With more than 6 elements I get the same failure that I see with my application. It seems like the same issue but at a different threshold. Can someone look at this?

Thanks,
Ralph


#2

@ralphjy - if you look at the BLE Chars on the OOB project, you will see that they are not all on the same UUID. The KW41Z has a limit of 10 per Service. You can make up a second UUID as they did in the OOB project. If you have a lot of Chars that are data type STRING, you could also run out of memory space. The Console from the boot/provisioning process would provide more information on the error. We have added a ticket to warn the user if they overrun the limit. Thanks for the question!