I have a project where I need to detect someone, up to about 8-10m away.
But, this detection needs to be directional.
This highly important project is a Nerf sentry gun, and I would like to add a 'friendly fire' feature to it, so that if you are wearing a tag/beacon, it doesn't fire at you.
It targets using a combination of Ultrasonics at close range, PIR and camera at long range.
The main weapon runs on a 2560p, with an Uno running the camera tracker.
Any ideas? The software for the camera tracking doesn't have the ability to do anything but track you (I can't add colour or shape detection).
I was thinking of maybe a very high power IR beacon?
The gun 'sweeps' left and right, so the detection needs to be reasonably focused if possible.
As this is quite frankly, a pointless project to fill my housebound days, I don't want to spend a fortune on the idea, but any input would be great.
I have some nrf24l01 modules kicking around, but they are not going to be directional, and that I assume that would be an impossible task to achieve.
What kind of range do you think is achievable with an IR beacon in daylight?
I have a whole pile of HT12E, F, D etc IC's lying around that could possibly handle the decoding.
I am thinking the GPS I am carrying reports wirelessly to the master Arduino (2560p on the gun) its Lat/long.
The master Arduino has it's own GPS position data and a compass so it knows which way it is pointing.
I wonder if then you could deduct some kind of crude directional data from that. I don't need super accurate information, just if you are within say a 15-20 deg arc.
I have a question regarding GPS modules.... Specifically a NEO-6M GPS.
If you had two of them set up within say 20m of each other, both receiving data from what would presumably be the same satellites, would the inaccuracy/drift be identical on both of them?
Or, is the inaccuracy/drift due to something else?
RF antennas can be directional, but then again they always have sidelobes in their response pattern, and if
there are objects reflecting the signal it won't work well. So outdoors perhaps...
Building Yagi antennas is one way to occupy your time!
Even with significant drift (NEO-6M GPS is apparent 2.5m).... a pair of GPS modules would probably work.
I only need to know if I am basically anywhere in front of the other GPS module. Actual directional accuracy isn't all that important.
However, this solution falls on it's backside if it's being used indoors
phoneystark2020:
I have a question regarding GPS modules.... Specifically a NEO-6M GPS.
If you had two of them set up within say 20m of each other, both receiving data from what would presumably be the same satellites, would the inaccuracy/drift be identical on both of them?
Or, is the inaccuracy/drift due to something else?
The relative accuracy of two GPS receivers in reasonably close proximity will be significantly better than the absolute accuracy of either. If one logs the position solution of a fixed GPS over time it will appear to wander around over time, but slowly (minutes to tens of minutes). These movements of two proximate receivers will be well, but not perfectly, correlated.
On the other hand GPS antennas have some directionalilty and the one on the person will obviously not have a fixed orientation. This will degrade it's accuracy, both in an absolute and relative sense.
If you're looking for a time sink, quantitatively evaluating this might be interesting.
You wrote this:"This highly important project is a Nerf sentry gun, and I would like to add a 'friendly fire' feature to it, so that if you are wearing a tag/beacon, it doesn't fire at you.".
If you concentrate on the beacon and detecting the beacon, you will make better progress.
An IR strobe light with a known pulse rep rate might work. Or a rotating mirror laser with reflectors could work.
Paul_KD7HB:
An IR strobe light with a known pulse rep rate might work. Or a rotating mirror laser with reflectors could work.
With a strobe (IR or visible light) and a retoreflective material on the "friendly" might be a possibility. You'd probably still have to do some image processing, but it would be a matter of looking for pixel areas with sharp contrast between strobe off/strobe on.
With a pair of cameras/colocated strobes on a modest baseline one could do triangulation to get range/proximity. Probably a Raspberry Pi sort of task though.
OK. I have a 30m+ Metre IR floodlight designed for use on CCTV systems. Stripped it down a while back because the power supply failed.
So, my thinking is to make a housing for this LED panel with some cooling, and then set this up to flood my target area.
I will then add maybe some kind of overlaid supply 'pulse' to the power supply, so that is flashes 'SOS' or something, but reasonably rapidly.
Then I carry a Nano or something that does nothing but look for this IR signal with a few Phototransistors.
If it find it, it simply sends a 'hold' signal wirelessly to the gun.
May be a Laser Distance Time of Flight sensor or a Doppler Radar . May also be a camera with area motion detector.
Detection who is friend is another system.
acjacques:
May be a Laser Distance Time of Flight sensor or a Doppler Radar . May also be a camera with area motion detector.
Detection who is friend is another system.
Yes, but with deliveries taking forever at the moment, I am trying to use what I have. Plus, don't want to spend a huge budget on a Nerf gun!
I also faced the same problem. Whenever that problem occur then I uninstalled the cctv software but set up was not connect.But such types of technical issue increase our frustration. Then I tried to reinstall buT cctv installation failed. If anyone has any solution then suggest to me.
phoneystark2020:
The master Arduino has it's own GPS position data and a compass so it knows which way it is pointing.
I wonder if then you could deduct some kind of crude directional data from that. I don't need super accurate information, just if you are within say a 15-20 deg arc.
Only one way to find out I think...
If the two GPSs are outdoors, and especially if its an open area like a field, then the distance calc between the two GPSs can be reasonably accurate, 1 or 2M maybe.
However when I tried this, using the TinyGPS++ library, the direction did have a lot of variation, maybe 45degrees or so, but that might just be down to how the angle calculation is performing over small distances.
Forget it indoors of course, and probably not reliable in places like forests\woods etc.
You might want to look at „laser clay pigeon shooting“. I believe the guns are equipped with infrared beacon/sensor, the targets are reflective. Targets are quite small, distance prob around 50m with good accuracy. (Had the chance to try it once, much fun.) Recognizing a „friendly“ reflective surface should be quite doable.