When HN users recommended it
1 HN user recommended this in 2024, in one comment.
20072026
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
1 HN user recommended this in 2024, in one comment.
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
I remember this article from the same site a while back - https://hforsten.com/heartbeat-detection-with-radar.html
I bought some cheap 10ghz and 24ghz dopper radar units off of amazon and started tinkering with them. You can absolutely pick up heartbeats and breathing just visually in the spectrogram.
Here's a few samples from that era:
10ghz pointed at ceiling fan:
https://www.youtube.com/watch?v=tIiFvByf1CQ
10ghz pointed straight up underneath a quarter that I flipped and allowed to land on the surface
https://www.youtube.com/watch?v=8riretP8ylE
10ghz pointed at a quarter spin on the surface
https://www.youtube.com/watch?v=5lnYvJoxRak
The comb filtering of the signal from the spinning surface is really cool.
10ghz module on amazon - https://www.amazon.com/HiLetgo-Microwave-Detector-Wireless-1...