Wrong, most of these radars are 24Ghz and specifically designed to detect body micro movements. They specifically give both human 'occupancy' and dynamic ranging information.
I wrote low level drivers for the ESP32 for all the ones I could buy and have tested all of them. The only one that does not try to give a human occupancy position is the car speed sensor.
This sounds very interesting, how do your drivers work? I'd love to try them out, but there's no documentation. I've made a sensor board with various sensors, I could really use some occupancy detection improvements on the LD2450B.
All the boards provided by HiLink have an on board MCU and offer a serial protocol of some sort.
I wrote a finite state machine based decoder for each them from the basic info on some documents,random example code and the textual description of the protocol from the aliexpress page. They are all wrapped in an outer state machine that provides entry and exit triggers. If you can read C++ the code is nothing fancy.
I have another more complete project for just the 2450 in another repo for the esp-idf with wifi provisioning and publishes presence to mqtt. I have 3 of these around the house.
here is the ld2450 multi object tracker:
https://github.com/mianos/mqttradar
It's pretty complete. There was some other guy who wanted an ld2450 tracker so I worked with him to get it going.
I wrote low level drivers for the ESP32 for all the ones I could buy and have tested all of them. The only one that does not try to give a human occupancy position is the car speed sensor.
The ld2450 can track three people at once.
https://github.com/mianos/hk-heltec-radar/tree/main/src