Pleasantly surprised to see electronics parts manufacturers on front page HN. The advancement of sensors nowadays is staggering - I'm reminded of the recent airborne dust sensor that's literally orders of magnitude smaller because it uses a new backscatter detection mechanism. All this technology available at very reasonable prices too.
I’ve played around with this (the KIT-CSK-BGT60TR13C). It is a very interesting gadget and the kit doesn’t need much configuration. In an afternoon I made a car detector for my bike that detects the presence of an approaching car from behind. I thought I had a winning startup idea then found out this idea has existed for years. :(
Tie that chip to a beamformer (silicon labs have a few) and you have a phased array radar, which is a radar that does not move at all (pretty cool in my opinion)
Also, 15usd is not cheap for this kind of chip. You can buy a full wifi 7 rf/modem or a 4 core arm64 soc with this kind of money.
You can't use an external beamformer with this chip; it has the antenna built into the package itself. The chip doesn't have pins for RF input/output to bypass the built-in antenna.
60GHz radar is very different from WiFi. 15USD actually seems about right for the functionality this chip offers.
What's cute about this is how far they went to make hobbyists happy. There's a way to connect it to Bluetooth and WiFi, and an Android app. There's compatibility with some Adafruit products. That's unusual for IC data sheets.
This is a phased array device. Angular resolution 20 degrees, range resolution 1 meter.
It's not a Doppler radar, so it can detect fixed objects. So if you're using it for people detection, you have to tell it where the fixed objects are. A ceiling mounted unit will see the floor. OK for people counting and such. Range is only 10 meters.
If you just want a motion detector to turn on a light, and IR isn't working for you, there are cheaper microwave detectors.
> What's cute about this is how far they went to make hobbyists happy.
Professionals are using hobbyist tools more and more, since these tools are just so much easier to use and don't require wading through datasheets which is like filling out tax forms.
Also IoT usecases require flexibility in connectivity.
As far as seeing and ignoring fixed objects, you can also remove any returns that have a near-zero velocity in radar and focus only on those objects that are moving.
Of course, indoor settings have a lot of non-stationary objects as well that might not be targets of interest to you, like fans, curtains blowing in the breeze, etc. So you can also develop algorithms to remove those signatures too.
Seeing fixed objects can be beneficial as well, for example, if you have a sensor deployed in a room but you don't know a priori what the room looks like. Longitudinal results and long range statistics can take you pretty far in seeing the room extents and layout and furniture, etc. Though a lidar sweep is better if you can get it
> Regulatory issues were likely a major factor that led to the demise of Soli and Motion Sense on future Pixel models. Soli operates in the 60GHz frequency, which is reserved for military and government use in India.. Many of the Google Pixel 4's Motion Sense gestures are available.. Nest Hub's Soli radar extends far enough to detect when you're sleeping, and to track your breathing.
Have a look at Hi-Link from China (on Aliexpress).
They offer 50GHz, 10GHz, 24GHz and 60GHz FMCW radar module boards for 10-30€ which are easy to reverse engineer on firmware and PCB level.
A lot of them are CW radars, a few FMCW and they also use the Infineon 60GHz radar chips. Very unusual for Infineon: with all tools and datasheets available without signing a NDA. Down to the register level.
There's an interesting Chinese company around (ICLink with their ICL1122/ICL1112) which offer highly integrated radar ICs. They can spit out raw ADC measurements of their downmixed baseband using Quad SPI at 20 or 40MHz when switching on their debug mode. Price range: ~10€. But datasheets are difficult to find. Example board: LD2410S.
The analog ones are easy to play with. You just need a DAC to drive their VCO and then can sample the I/Q pins with an ADC. That how a lot of the 24GHz modules (like the LD1125H) work.
> The analog ones are easy to play with. You just need a DAC to drive their VCO and then can sample the I/Q pins with an ADC
Do you have any reference or notes on how to access the IQ pins on one of these devices (ideally one of the FMCW ones)? I've been wanting to play around with one of these 24 GHz or 60 GHz units for coherent radar but it seems like most of the boards only report on distances over serial links. If there's an easy way to tap into the analog IF signal after down conversion I'd love to see how to do that!
I got one of those cheap waveshare 60GHz modules with heart rate detection a few years ago. My goal was to build a sleep tracker - stick it under the bed pointing up, detect getting in and out of bed and falling asleep.
Unfortunately even just pointed straight at me with no obstructions and nobody else in the room the data was more or less random noise...
I wonder if now (after few more years of development, more reputable manufacturer and more money) it is worth trying again?
Thinking of starting a project to detect rainfall/snow/mist - has anybody used those mmWave sensors in a similar application? I've researched some of those and seems many are build for specific application, like a car rain sensor, which hardly provides broader output to apply further modeling.
obstacle avoidance for rc airplanes would be nice, maybe combine it with one of the autopilots out there. Learning to fly rc airplanes is pretty easy these days, the flight controllers can hold your hand through just about everything.
I built a FT Explorer with their FT Aura gyro system and it's so much more fun flying in a gentle breeze when not having to worry about keeping the plane upright and level. Radar ground detection and obstacle avoidance would be a crazy cool addition.
27 comments
[ 3.2 ms ] story [ 55.3 ms ] thread"Inside a $1 radar motion sensor" (2024), 100 comments, https://news.ycombinator.com/item?id=40834349
"WhoFi: Deep Person Re-Identification via Wi-Fi Channel Signal Encoding" (2025), https://news.ycombinator.com/item?id=44685869
Also, 15usd is not cheap for this kind of chip. You can buy a full wifi 7 rf/modem or a 4 core arm64 soc with this kind of money.
60GHz radar is very different from WiFi. 15USD actually seems about right for the functionality this chip offers.
This is a phased array device. Angular resolution 20 degrees, range resolution 1 meter. It's not a Doppler radar, so it can detect fixed objects. So if you're using it for people detection, you have to tell it where the fixed objects are. A ceiling mounted unit will see the floor. OK for people counting and such. Range is only 10 meters.
If you just want a motion detector to turn on a light, and IR isn't working for you, there are cheaper microwave detectors.
Professionals are using hobbyist tools more and more, since these tools are just so much easier to use and don't require wading through datasheets which is like filling out tax forms.
Also IoT usecases require flexibility in connectivity.
Of course, indoor settings have a lot of non-stationary objects as well that might not be targets of interest to you, like fans, curtains blowing in the breeze, etc. So you can also develop algorithms to remove those signatures too.
Seeing fixed objects can be beneficial as well, for example, if you have a sensor deployed in a room but you don't know a priori what the room looks like. Longitudinal results and long range statistics can take you pretty far in seeing the room extents and layout and furniture, etc. Though a lidar sweep is better if you can get it
https://en.wikipedia.org/wiki/Pixel_4#Motion_Sense
> Regulatory issues were likely a major factor that led to the demise of Soli and Motion Sense on future Pixel models. Soli operates in the 60GHz frequency, which is reserved for military and government use in India.. Many of the Google Pixel 4's Motion Sense gestures are available.. Nest Hub's Soli radar extends far enough to detect when you're sleeping, and to track your breathing.
They offer 50GHz, 10GHz, 24GHz and 60GHz FMCW radar module boards for 10-30€ which are easy to reverse engineer on firmware and PCB level.
A lot of them are CW radars, a few FMCW and they also use the Infineon 60GHz radar chips. Very unusual for Infineon: with all tools and datasheets available without signing a NDA. Down to the register level.
There's an interesting Chinese company around (ICLink with their ICL1122/ICL1112) which offer highly integrated radar ICs. They can spit out raw ADC measurements of their downmixed baseband using Quad SPI at 20 or 40MHz when switching on their debug mode. Price range: ~10€. But datasheets are difficult to find. Example board: LD2410S.
The analog ones are easy to play with. You just need a DAC to drive their VCO and then can sample the I/Q pins with an ADC. That how a lot of the 24GHz modules (like the LD1125H) work.
Do you have any reference or notes on how to access the IQ pins on one of these devices (ideally one of the FMCW ones)? I've been wanting to play around with one of these 24 GHz or 60 GHz units for coherent radar but it seems like most of the boards only report on distances over serial links. If there's an easy way to tap into the analog IF signal after down conversion I'd love to see how to do that!
Unfortunately even just pointed straight at me with no obstructions and nobody else in the room the data was more or less random noise...
I wonder if now (after few more years of development, more reputable manufacturer and more money) it is worth trying again?
What steps did you take to limit the detection bandwidth? SNR is often a bandwidth problem, not a sensitivity problem.
Could it be used as a "life" detector in collapsed structures after earthquakes?