I ordered two HB100 Doppler radar modules from China. They arrived and I took them down to the lab for a quick test. First off, the boards look nice. Good solder masks and silkscreens. On the surface they look of good construction and materials. Quickly soldered some leads to the 5V, Gnd, and IF connections. To these I applied my power and connected the IF lead to my scope. Powering up the unit appeared to work. It is always a good think not to see smoke. Now I waved my hand in front on the unit and and did not see any response on the scope. Now I read the documentation I was able to scrounge and found that the signal would be a sin wave in the micro/millivolt region with a DC offset.
So I adjusted the scope for AC coupling, cranked the sensitivity up and waved my hand again. Success, but only just when the object is a few inches away from the sensor. The document talked about a range of 20 meters! So I gave up, and went upstairs to pout. Goggling I did find a reference that might indicate the sensor is not good in tight confines (like my lab). Next step if to take the rig outside.
Although this is a Doppler sensor and only reports speed of an approaching object, I still hope to use it for AVC obstacle avoidance. My hope is pinned on the fact that the amplitude of the sin wave output is inversely proportional to object range. With an appropriate comparator, I might be able to sound an alarm for objects closer than some panic distance.
I have one of these for the same purpose. Hope it works a bit better outside. Haven’t experimented with mine yet.
The documentation for these things is pretty awful. After an hour of Goggling I did find what passes as a datasheet and a user manual including a few circuit designs. The big take away is a significant amount of amplification is needed as well as some filtering. Hope to give it a shot this weekend.
Any progress with it? Cheers
As the summer winds down (where did it go?) I have less time. Right now I am getting the kids ready to go off to college. I hope to get back to this soon.
openimpulse.com/blog/products-page/product-category/hb100-microwave-sensor-module/
have links to HB100_Microwave_Sensor_Module_Datasheet.pdf and HB100_Microwave_Sensor_Application_Note.pdf
As in the Documentation said you should use AC-Ampilifer-System … to Scale the Signal to whatever ..
Here for example you can buy a hb100 with ampilifer .. scaling the output-signal to 0..5v … baseline is at 2.5v
http://www.sunrom.com/sensors/speed/microwave-doppler-radar-sensor-for-motion-and-speed-sensing?currency=EUR
in their datasheet (with images) (http://www.sunrom.com/files/1195-datasheet.pdf) you can see how good that works
…
well i personally think .. buying a HB100 without having a OpAmp doesnt make sense cause you can’t sense long ranges … its like trying to receive a sat.tv-signal with a rod