BLE Default Connection Interval

[gocchan]

I'm developing with an STM32WBA2.
I want to communicate via Bluetooth every 10ms, but where in the source code should I modify the default connection interval?
I couldn't find a relevant item in CubeMX's STM32_WPAN.

[Imen.D]

Hello ​@gocchan ,

The default connection interval is defined in app_conf.h.

This ST wiki will help you to define the BLE general parameters: STM32WBA Bluetooth® Low Energy – Power consumption applications - stm32mcu

 

[gocchan]

Hello ​@Imen.D ,

Thank you for your comment.
I checked app_conf.h but couldn't find a definition related to the connection interval (I've attached the file).
I also checked the STM32_WPAN file but couldn't find the symbol CONN_INT (I've attached this as well).
The project I'm currently developing was created using CubeMX 6.18.0 with STM32WBA23KEU7 specified in the MCU/MPU Selector. The CubeIDE version is 2.2.0.
 

 

[jackwatsan]

Hi @gocchan, since app_conf.h doesn't have it for STM32WBA, try looking in app_ble.c instead — the connection interval min/max is usually passed as a parameter when the connection request is made (e.g. in the aci_gap_create_connection or hci_le_create_connection call), not defined as a standalone macro. Search for "conn_interval" or "Conn_Interval_Min/Max" in that file. For 10ms you'd want both min and max set to 0x0008 (8 × 1.25ms = 10ms).

[Andrew Neil]

the connection interval min/max is usually passed as a parameter when the connection request is made

​@gocchan Note that this is just a request: there is no guarantee that the Cenrtal will give a particular value - especially if it’s a phone/tablet or similar ...