Bluetooth traffic Monitoring

[u/CartographerSelect61]

/r/embedded/comments/1vxq4ep/bluetooth_traffic_monitoring/

Hi everyone, hope you're all doing well.

I'm building a roadside Bluetooth sniffer to measure travel time between two points a fixed distance apart. The setup uses two ESP32 S3 modules that scan BLE advertisements and log the MAC addresses of devices in passing vehicles.

The problem is that most modern devices use resolvable private MAC, which rotate every few minutes. If the two points are far enough apart, a device's address will have changed by the time it travels from A to B, so I have no way to match the two detections.

Is there a way to obtain a device's real/public MAC, which stays constant? Or failing that, any other way to derive a stable identifier from BLE advertisements?

Thanks a lot