### 1. About the STEVAL-IDB012V1 Evaluation Kit
We have purchased the STEVAL-IDB012V1 evaluation kit. On ST's official website, we found a software package for QUUPPA tag emulation using BlueNRG-LP/LPS (en.STSW-QUUPPA-ETAG.zip). After downloading, we extracted it into the BlueNRG SDK (STSW-BNRGLP-DK). However, when I tried to compile the project using Keil, I encountered errors. The error details are shown in Attachment 1.
The version of Keil I am using is 5.40, and the compiler version is 6.09.
I could not find a detailed solution to this issue in your forums or documentation. Additionally, there is no detailed explanation of the purpose of this project, only a brief mention that it is a "QUUPPA tag emulation."
### 2. About PCB Design for STM32WB09
Since the STM32WB09 is a relatively new product, I have not found much information regarding its PCB layout guidelines.
We followed the design guidelines for BlueNRG (`AN5526 - Guidelines for PCB Design on BlueNRG-LP/BlueNRG-LPS/STM32WB0 MCUs - STMicroelectronics`) to design a minimal system board for the STM32WB09.
After testing, it works well, but I would like to eliminate any potential issues arising from the subtle differences between the two chips. Could you provide detailed design guidelines for the STM32WB09?
### 3. About Antenna Array Design for AOA Base Stations
Regarding the hardware design of the antenna array for AOA base stations, there is a lack of relevant documentation from your side. I had to search for information elsewhere.
### 4. About Implementing AOA Positioning Using Code (This is the Most Important Point)
We want to design a base station using the STM32WB09 for direction finding in connectionless scenarios.
However, you have only provided a limited number of APIs, and I cannot see the implementation of these functions.
I used two custom STM32WB09 development boards to test the `BLE_Beacon_AoA_Tag` and `BLE_Beacon_Scanner_AoA_Locator` examples from the SDK.
I was able to receive IQ data via the serial port, but there is a serious issue:
After receiving a small number of IQ samples, the following error is triggered:
```c
case HCI_LE_PERIODIC_ADVERTISING_SYNC_LOST_SUBEVT_CODE:
{
APP_DBG_MSG("Sync lost! Restart the scanner device to get again the Beacon AoA Tag IQ samples !\r\n");
//device_state = START_SCANNING; //TBR???
}
```
I noticed that you might have intended to restart the scanning process, but the code is commented out, and the "TBR???" comment is left in the official SDK release. Is this a hardware design issue causing the connection to drop?
Furthermore, I reviewed the `RM0505 - STM32WB09XE Ultra-Low-Power Wireless 32-bit MCU Arm-Based Cortex-M0 with Bluetooth Low Energy and 2.4 GHz Radio Solution - STMicroelectronics` document, which describes the register design for the STM32WB09. I found some information related to AOA direction finding, but there is still a lack of detailed explanation regarding antenna switching control.
I also studied Texas Instruments' RTLS_Toolbox, where they use timer interrupts and DMA+GPIO to control RF switch toggling, as well as guard times and other AOA-related properties.
Could you provide detailed information and explanations on how this is handled in your system?
Additionally, in STM32CubeMX, I noticed that PB0-PB6 can be configured as `RADIO_ANTENNA` with very high-speed settings. These are clearly intended for antenna switching, but I could not find any documentation on how to use them.
For example, if I want to configure a 4x3 array of 12 antennas, how should I set up my code to cycle through these antennas while accounting for signal instability caused by RF switch toggling, in order to collect accurate IQ data?
I am an independent developer, and after the project is completed, I plan to open-source both the hardware and software. I welcome everyone to discuss and collaborate. My email address is 3228558272@qq.com.
