topic Re: eatt_central in kw45 in MCX Microcontrollers

eatt_central in kw45

Chan_17 — Tue, 19 Aug 2025 17:40:11 GMT

Hello nxp team,
I am using eatt central example to receive multiple sensor data from (eatt peripheral) i am successfully able to connect 2 devices but when I am seeing the data in uart teraterm at 112500 baud rate there is so malfunction in data received like for I device i am able to get data from some time than other device for sometime

Re: eatt_central in kw45

luis_maravilla — Tue, 19 Aug 2025 21:55:55 GMT

Hello,

What are the differences in data shown with the example photo from Bluetooth Low Energy Demo Applications User’s Guide in Chapter 5.4 EATT Central?

Could you help us describe your setup to try replicate the scenario?

[What are the 2 devices? KW45B41Z-EVK / Custom board]

Did you implement modifications on the code from the SDK? and which SDK version is the example from?

Could you help us sharing the log in teraterm please?

Any other information would be highly appreciated.

Best Regards

Luis

Re: eatt_central in kw45

Chan_17 — Wed, 20 Aug 2025 11:59:19 GMT

HI Luis

1.Yes we modified SDK example code of Eatt_central for multiple connections.

2.two devices means 2 KW45B41Z-EVK board as peripherals and we used SDK example code without any changes.

3.For central we used KW45B41Z-EVK board, we modified SDK code for multiple peripheral connections.

Problem : its not going to write descriptor A , I attached screenshot of tera term,

SDK version :24.12.00

manifest version : 3.15.0

Re: eatt_central in kw45 multiple connections

Chan_17 — Thu, 21 Aug 2025 05:46:40 GMT

SInce it was not working for Service A , i tried with Service B and connected 2 peripherals( KW45B41Z-EVK board) and same for central. But we are getting only one peripheral data.we are not getting 2 peripherals data even after updating eatt_central for

multiple devices.

Re: eatt_central in kw45

luis_maravilla — Thu, 21 Aug 2025 23:37:28 GMT

I would strongly recommend updating to latest SDK version [25.06] and updating the NBU from newest SDK to each KW45B41Z-EVK. [Updating NBU for Wireless Examples]

In Bluetooth Low Energy Application Developer's Guide Chapter 9.10 is described how the Multiple connections work for BLE demo applications and the considerations need to be taken.

Consider that gAppMaxConnections_c contains the maximum connections "tested" by the application. As this is not just related to the app, it is involved the memory, security, and environment of the device, this will be different in each application. If you want to modify to a higher value for multiple connections to be supported, every customer will need to implement by their side the modifications for their application; I would recommend adjusting gAppMaxConnections_c on both codes for central and peripheral.