I would like to build a blind spot detector for my motorcycle. I researched a little bit about blind spot detector technology and I narrowed down to two options: 1) use ultrasonic sensors to measure the distance of the vehicles next to the bike or 2) use radar sensors to sense moving vehicles close to the bike.
I am looking for guidance on which of the two sensors can work better with an arduino and if anyone has tried either one before.
With the ultrasonic sensors I found many examples that can measure distance and I think their implementation for a blind spot detector is pretty straight forward. The only concerns I have are that they can not differentiate between a stationary and a moving car. So they would give off a signal next to a parked car.
So I thought of trying a radar sensor. I looked online and there are cheap radar modules in the X-band, the HB100 or HB200A. I have some questions regarding radar sensors.
In the examples I read online these sensors are stationary and they can detect moving objects. Can they work well to detect moving cars if the sensors are mounted on a bike and the bike moves as well?
I also noticed that the above sensors have a wide detection angle of about 70 degrees in the horizontal? Can the angle be reduced to a more narrow range (20 degrees) or is it this strictly a function of the X-band frequency?
The above radar sensors usually have a detection range of 20m. For blind spot detection applications I would want the range to be limited to 5m or 6m otherwise I will get many false alarm from vehicles that are farther away and are not in the blind spot of the bike. Is it possible to limit the maximum detection range? If yes is it as simple as reducing the input voltage to the sensor?