WiFi signals can measure heart rate

I do it using MMWave sensor, 60Ghz one. Want to have more of them but installation is a pain as these need to be mounted on ceiling so WiFi based sensor would be awesome!

Do you have a writeup about this somewhere? I'd love to know more.

You can buy them on Aliexpress for $5. YouTube and a cursory google search will give you many many options to choose from for examples and tutorials.

"Low cost mmWave 60GHz radar sensor for advanced sensing" (2025), 50 comments, https://news.ycombinator.com/item?id=44665982

"Inside a $1 radar motion sensor" (2024), 100 comments, https://news.ycombinator.com/item?id=40834349

"mmWave radar, you won't see it coming" (2022), 180 comments, https://news.ycombinator.com/item?id=30172647

"What Is mmWave Radar?: Everything You Need to Know About FMCW" (2022), 30 comments, https://news.ycombinator.com/item?id=35312351

Tell more about your setup!

Infineon 60GHz IoT FMCW radar modules have all datasheets published. That's super rare for Infineon - usually they are the worst NDA-hell on earth.

Chinese vendors sell uC+Radar-Module units on Aliexpress for around ~20-30€. They Infineon-based boards are super easy to spot by looking at the Antenna-on-Chip layout.

You can cut off their head (microcontroller) and directly attach your favorite uC onto the SPI bus to talk to them. Or use the existing one.. not overly complicated to reverse engineer the schematic.

Example: MicRadar RA60ATR2

There are a lot of radar modules out there in the wild.

But not all of them are good for doing stuff like this.

You need full raw I/Q and DAC access to sweep the frequency.

Unfortunately no. But fortunately, it isn't something new I have built. I use a Seed Studio sensor MR60BHA2 which has an ESP32 which sends the data to Home Assistant through ESPHome. Once it is in Home Assistant you can do automations and notifications. I mostly use it for elderly care. I have another DFRobot C1001 sensor but waiting for ESPHome to add support for it. It has fall detection also which is why I am planning to replace it. They are fairly accurate; ~90%; has been my experience. They work better when mounted on ceiling and have a cone like coverage.

don't get the $5 ones, they are probably just presence detector or at best distance detector and probably work on 24Ghz. Get the 60Ghz for breathing, heart rate, posture etc.

posted some details at https://news.ycombinator.com/item?id=45150761. happy to answer any additional queries you may have.