I was wondering if any one might know of a way to detect the presence of a human or animal wirelessly regardless of if they are moving or not.
The catch is I do not want to use IR, PIR or Ultrasonics. What got me thinking about this was at one point I had messed some thing up with an electronics project and I noticed that when ever my hand would come with in an inch or two of this wire it would start to light an led.
I would like take that idea and expand on it and make it longer range (12 foot diameter would be nice). If any one has any suggestions I would love to hear them. I think that it was acting as a capacitive sensor and detecting my capacitance as a change but I could be very wrong about that.
Sorry I forgot to mention I don’t mind if it detects things like cars or bike or what ever if it comes into the sensors field. That is actually preferable.
I will research into the doppler motion detectors but would prefer it if the sensor could detect things not in motion.
The idea is to turn on the sensor. Adjust it to the point where when you leave the field it turns the led off and when you or any thing else for that matter enters the field it turns the led back on.
hcker2000:
I will research into the doppler motion detectors but would prefer it if the sensor could detect things not in motion.
The idea is to turn on the sensor. Adjust it to the point where when you leave the field it turns the led off and when you or any thing else for that matter enters the field it turns the led back on.
If nothing is in detection field of the sensor and then something enters it, the object is in motion. Likewise, if the object is in the sensor’s field and leaves, it is in motion. A motion detector sounds like what you need. Your sensor just needs to make sure that catches the transistions.
You didn’t tell us any specifics like range, detection area, location (indoors/outdoors), and other information that will be crucial to provide any sort of useful advice.However, I’ll add two other ideas:
Microwave motion sensors are also something to investigate. Those are the types of sensors our local grocery stores use to automatically open the doors.
A video camera and software to examine the captured frames. If the frame contents change materially (and materially is the operative word), then an object has been detected. This approach requires additional considerations such as adapting to temperature and light conditions. However, it arguably is the most flexible approach.
Sensor range of 12 radius from sensor as the center point.
Simple to build
indoor/outdoor usage
I am hoping for some thing capacitive or inductive sensing that will sense animals or metal objects (cars for example).
PIR would be acceptable but the cost is prohibitive. I would like to eventually build 10 to 20 sensors. I just thought of what does some thing similar and that is a theremin. I want some thing like that but with longer range.
hcker2000:
Sorry I forgot to mention I don’t mind if it detects things like cars or bike or what ever if it comes into the sensors field. That is actually preferable.
I will research into the doppler motion detectors but would prefer it if the sensor could detect things not in motion.
The idea is to turn on the sensor. Adjust it to the point where when you leave the field it turns the led off and when you or any thing else for that matter enters the field it turns the led back on.
I think you want a video camera and a polygon region for change detection using video analytics.
Otherwise, you must simplify this to being a motion detector, sensing either infrared (commonplace PIR) or RF doppler.
Camera won’t work. Forgot to mention one of the requirements is it work complete darkness.
PIR is the easiest option to go with and it is passive which is a major bonus. Doppler would probably have longer range but would also chew threw batteries I would guess and it can be detected.