When HN users recommended it
1 HN user recommended this between 2018 and 2019, in 2 comments.
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 between 2018 and 2019, in 2 comments.
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.
Newer version in this post - http://hforsten.com/third-version-of-homemade-6-ghz-fmcw-rad...
An interesting application of CW radar - http://hforsten.com/heartbeat-detection-with-radar.html
At 45 years old I feel like I've learned quite a bit, but when I read stuff like this I wonder if there are enough years left in my life to learn what to takes to put something like this together.
I will say that the little CW doppler radar boards are fun to tinker with. You can get them on amazon for <$10 shipped, power them with 5 volts and just wire the output to a microphone jack.
https://www.amazon.com/SMAKN-Microwave-10-525GHz-Doppler-Det...
This is what a coin toss over a 10GHz doppler device sounds like: https://www.youtube.com/watch?v=8riretP8ylE
The HB100 [0] and CDM324 [1] are very inexpensive little CW doppler radar modules at 10GHz and 24GHz respectively. Feed them 5v and send the mixer output to a small microphone amp/input jack and you can record the frequency beat of most objects in motion.
[0] https://www.amazon.com/dp/B00FFW4AZ4
[1] https://www.amazon.com/dp/B07WH67J9W
This is what it sounds like when you toss a quarter in front of an HB100. https://www.youtube.com/watch?v=8riretP8ylE
The bowtie looking part is the actual flight, the other part right after that is it bouncing off the counter.
Spinning same quarter - https://www.youtube.com/watch?v=5lnYvJoxRak
Shining it at parts of a ceiling fan - https://www.youtube.com/watch?v=tIiFvByf1CQ