How to make changed UUIDs to take effect ?

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How to make changed UUIDs to take effect ?

1,020 Views
chandramohanc
Contributor II

I am trying to change UUIDs in gatt_uuid128.h, but after changing no matter how many times i compile, i see the old UUIDs always when i discover services and characteristics using my mobile app, please explain am i missing something

FYI:

I am using the given bluetooth_wireless_uart_demo example code

I did not change anything other than the UUIDs

I am using IAR compiler

Hardware FRDM-KW40Z

Before :

UUID128(uuid_service_wireless_uart, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x00, 0x01, 0xFF, 0x01)
UUID128(uuid_uart_stream, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x01, 0x01, 0xFF, 0x01)

After:

UUID128(uuid_service_wireless_uart, 0xba, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x00, 0x01, 0xFF, 0x01)
UUID128(uuid_uart_stream, 0xab, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x01, 0x01, 0xFF, 0x01)

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4 Replies

566 Views
santiago_lopez
NXP Employee
NXP Employee

Hi Chandra,

 

Sometimes smartphone applications store the last values from the device discovery procedure. It takes some connections for these applications to update that information. I implemented the changes you mention and tried to read the UUIDS using a Motorola G. After 3 or 4 connections (without changing the FRDM-KW40 firmware) the information in the application was updated.

pastedImage_1.png

If you can´t see the change, please try with another smartphone or application.

 

Best Regards

 

Santiago Lopez - Systems Engineer

566 Views
b_manojkumar521
Contributor II

Hi Santiago

Can you explain me how to give/change the name for profiles pastedImage_1.png

I'm trying to give the name instead of unknown service and unknown characteristic 

If you know the concept please explain to me, sir

Thanks in advance .!

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566 Views
santiago_lopez
NXP Employee
NXP Employee

Hi Manoj,

Showing the name of the attributes in the smartphone application depends on the smartphone having the correlation list between the UUID and the attribute name. When the client retrieves the GATT database information from the server, it will not share service, characteristic or attribute names but UUIDs. Each UUID is tied to a specific service, characteristic or attribute, some of them defined by BLE org and some others custom (like the Wireless UART in our example)

The ones defined by the BLE org, like 0x180D for Heart Rate Service, will be already defined in the smartphone application UUID database, and once it sees the known UUID, it will report the right attribute name. For custom UUIDs, it is less likely to have the real name in the UUID database and it will report Unknown UUID.

Here is a list of the BLE registered UUIDs https://www.bluetooth.com/specifications/gatt/services/ 

Saludos

566 Views
b_manojkumar521
Contributor II

I have another issue that, 

              1. How to send data from client to server

              2. And with that data, I need to toggle an led 

Save me with giving your valuable answer 

Thanks in advance .! Sir .! 

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