How to create user Service and/or modify GATT characteristc for BCM20736?

[Anonymous]

Hi,

We are trying to assign unique ID to our modules. OTA update firmware is one way. But because the update is very little change, we are thinking other way to realize it. Then comes out following question:

1. Is it possible create user service and/or modify GATT characteristc for BCM20736? I am not sure the chipset has internal memory for user, although it has the feature that support for EEPROM and serial flash interface.

2. If it is yes for the question without/ with external flash, do you have any doc provide more detailed information?

Thanks!

[MichaelF_56]

Are you asking if you can create your own user defined GATT DB?  Yes.

Are you then asking if memory is available for your custom application/GATT DB?  Also Yes.

[Anonymous]

1. Then can I modify the GATT DB after the module is built? for example, the module is already uploaded with original firmware and later want to modify one UUID. Is there a doc shows how to modify the UUID over the air(wireless) using smart phone?

2.  In case of using external memory for the GATT DB modification, do you have any doc to show how to make it happen?

[MichaelF_56]

ellenj

The GATT DB within your application is stored in the NVRAM of the module, along with the rest of your application.

I think there is a sample in this thread that shows how to change/re-define GATT attributes at runtime: How to change the GATT database after init (bleapp_set_cfg) ?

markusz  kzalkin@broadcom.com  j.t kwang

[VictorZ_46 · Accepted solution]

You can write an application that supports firmware upgrade and program it in the factory. When time comes you can write different application with different GATT DB and download it from a smartphone.