Hello STMicroelectronics community,
I'm currently working on a project involving the BlueNRG-2N Bluetooth Low Energy (BLE) module, and I'm looking to reduce the Bluetooth range to approximately 1 or 2 meters (means over 2 meter, I want my bluetooth server side = a BlueNRG-2N chips inside a board not detected by the client BT side = Smartphone ). The BlueNRG-2 module offers an extended range, and for my specific application, I need to limit the range to this shorter distance. After going through the BlueNRG-2 documentation and software development kit (SDK), I have identified that I should adjust the transmit power level to achieve this goal.
I have already located the aci_hal_set_tx_power_level function in the SDK, which allows me to set the transmit power in dBm.
I tried :
aci_hal_set_tx_power_level(0, 0); // Disable high power mode and set low power level
However, still Bluetooth can be detected from 4 meters !!! I'm seeking further guidance and best practices on how to configure this function optimally for a range of 1 to 2 meters. Additionally, if there are any other relevant parameters or settings that I should adjust to achieve this reduced range, please kindly advise.
To provide context, I have considered lowering the transmit power, adjusting the advertising parameters, and using non-connectable undirected advertising to limit the range, but I would appreciate your expert insights and recommendations on how to fine-tune these settings.
Here a resume for my research :
To reduce range :
* Lower Transmit Power (I tested with lowest parameter but still up to 4 meters !!)
*Antenna Design (Use an Antenna with Reduced Gain): I cannot control this parameter at this moment !
* Modify the Bluetooth Advertising Parameters : I need more info about this !
Thank you in advance for your assistance. Your expertise will greatly contribute to the success of my project.
Best regards,
