x-band motion detector project
i want to know if there is a way to detect the direction of the moving object using parallax x-band motion detector ? the second thing if i can detect the distance of the moving object behind the wall using the same device? the third is if the device is compatible with arduino uno?
BR.
BR.
Comments
2) distance is more complex, involving timing of the return signal. This is being worked on in other areas, if you are interested to join.
3) anything is compatible with anything, it is a question of degree, as in how much work you wish to do. That being said, it is a simple serial connection, I believe arduino can do that, but I am not an arduino expert.
2) do you have an idea to detect the distance of a moving objects using RF devices?
Yes, you can, but a bunch of work need to be completed. To my knowledge, nobody has posted an easy solution yet, so this is a valuable project. This is not a trivial task. Its probably impossible, but thats no reason not to do it anyway.
Lets get started.
What you want to look at is RADAR and LIDAR. There are example of these on for example Hack-a-day
http://hackaday.com/2014/03/17/radar-imaging-in-your-garage-synthetic-aperture-radar/
The Doppler effect is "advanced" part of the project. This might be doable in software, once the detector is set up properly.
The first step might be determing DISTANCE. This might be done using down-conversion http://en.wikipedia.org/wiki/Digital_down_converter (I think thats the right link, its just for reference anyway. Its too deep for me)
Rather than re-invent the wheel, it might be possible to use an existing part to handle the timing. The timing chip that a friend made is the sequential-equivalent-time-sampling
(SETS) circuit to be available from the open source version of a laser range finder.
http://lightware.co.za/shop/index.php?controller=attachment&id_attachment=7
The laser range find can easily determine distance to target, many times per second, for distances greater then we are normally concerned with at a hobbyist level.
It might be possible to use this same timing chip for timing microwave pulses instead of laser pulses.
I've been interested in this for quite some time, but its a bit beyond my ability to do on my own.
Do you want to give it a go?
If you replaced the manual pot with a digital pot, could you automatically adjust sensitivity to get some crude idea of distance to the moving object?
DOPPLER EFFECT
Think of a horn being honked in a passing car. To the driver, the sound is constant. To an observer, the sound is high pitched as the car approaches and is lower after the car passes. That's because on approach, each successive sound wave is sent from a slightly closer position to the observer. The sound waves get compressed, resulting in a higher frequency. The opposite happens as the car moves away. It's called the Doppler effect for Austrian physicist Christian Doppler, who first put forward the theory in 1842.
The same effect applies to "pings" from the plane to the satellite orbiting in a fixed position, which would arrive at a higher frequency if the plane was moving toward the satellite and decrease in frequency when moving away.
"By analyzing that you can determine speed and direction," said Joseph Bermudez Jr., chief analytics officer and co-founder of AllSource Analysis, a commercial satellite intelligence firm. And by determining the area from which the last signal was sent, then estimating fuel left, it "could give you an approximate area of where the aircraft impacted."
http://www.hindustantimes.com/world-news/malaysianairlinemystery2014/mh370-how-classroom-physics-helped-narrow-malaysian-jet-search/article1-1200238.aspx?
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