It has been a while but I am wondering if there still is a group in or near Atlanta GA that I could test my little home brewed lidar jammer.
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It has been a while but I am wondering if there still is a group in or near Atlanta GA that I could test my little home brewed lidar jammer.
Any Jpg's of it?
:geekon:
Pix or it didn't happen. :lol:
I will get some pictures of the unit here as soon as the resin hardens around the Jamming heads ( 6, 230mw Ir Leds 880nm ) I still need to pick up a project box
for the Pulse sweep generator.
I don't actually have a detector circuit for it yet. I plan to try and tie it into an cheap radar/lidar detector just to test. I figure if the Laser led lights on it I can pigtail off of it to fire the sweeper.
Just curious if 15 bucks+time has any effect at all on jamming a gun. the system as it is drives my current laser/radar detector nuts. so, Meh it may or may not work Just curious though.
I will get photos up as soon as I can. just I have a business to run and this has been a little side project from 2 years ago when I first posted here .
We are around! category4 and M6D have the guns, and rsatmans can invite you into the Georgia Testers social group here.Quote:
Originally Posted by Solion
Here are a couple of photos of the IR leds now suspended in alumalight resin casing Should be pretty rugged and waterproof to boot.
more photos to come as soon as I rebuild the pulse sweeper to fit something allot small than the breadboard.
Let me know when your next meeting is. It should be fun to see how big a FAIL this will be.
Solion
A little link to you tube videos of the head units actually working. I am actually hopeful some of my programming sweeps of various PPS might actually work. Instead of a solid stream of pulses, a sweeping or stuttering changeup of pulses may be the trick ( wont know till I test)
youtube(dot) com/user/thundolis#p/a/u/1/uvUgW7qA5d4
youtube(dot) com/user/thundolis#p/a/u/0/yOIfaRTLOgk
But the big thing is the shear burnination of my output. no they are not laser diodes but hell, the combination of output of all of them is.. epic? won't know if it means a thing till I get to test my mad science budget toy . Tell you this much. If it works I promise to post the schematics for everyone to enjoy.
There is something that has been grinding on my brain. I have to be honest here as I am a little confused about something and perhaps someone can set me straight on it. and it concerns the actual pulses from a lidar gun and what was told to me about the brand name expensive jammers.
Here is what I was told, the expensive units sense the lidar pulse then sends the same pulse (rate/width/time) back to the gun thus confusing it. Now I probly heard the sales guy wrong on this so feel free to correct me. But those pulses used and the rate they are emitted are the property of the lidar gun Manufacturer.
Scientific Atlanta cannot use the same pulse structure as lets say that of LTI (they would get sued) . So it stands to reason that neither can Blinder, Laser Star or anyone else recreate the pulse information EXACTLY because they would get sued. Now this is where it gets funkadelic as an engineer. Can I accidentally get sued for building my own toy? If by tweaking some programming and giving out what I find is a "best jam code " for my basement build of a lidar jammer.
I am not here to make any money. I am part of OSC (Open Source Circuits )
and wonder if I stumble on a jamming rate that works and give it away without knowing that it is the property of someone else. will I loose my home? Scary idea since all I wanted to do was make Lidar guns useless for 15.00 and a soldering iron.
Just questions from the world of maaaaaadd Sccciiieennceee
Solion
No, you can't get sued for single, personal use, with no profit motive, and no commercial connection at all, of a patented idea, in general terms. I am not a lawyer, and don't give legal advice. That's just my understanding of it based on reading a lot of intellectual property laws over the years (due to my line of work).
I don't think pulse rates are patentable. That would be akin to Ford patenting 55 mph. How a gun determines speed (specifically), how it detects JTG, its strengths, etc., those are patentable.
Now, looking at your videos, it seems you're on the right track. If you can get it to pulse back correctly (and that will be tough, because there is actually one brand which sends out one pulse rate then switches to another to fool older jammers), then it will work but its a matter of how well. In other words, you might need to add several more LEDs to each head, and keep adding until you get a number which works well at a significant distance.
Cool stuff! :)
I am no engineer, and I'm truly weak on the technicals, but I do wanted to wish you best of luck! This is definitely something to keep my eyes on!
Great .
From the smallest seed grows the tallest tree :)
Just some ideas : using those clusters of ir leds
from night surveillance camera ?
Or cluster :
LED High Power Illuminators
L850-66-60 consists of 60 chips of 850 nm wavelength mounted in a TO-66 package.
L850-66-60-550 consists of 60 chips of 850 nm wavelength mounted in a TO-66 package assembled with a heat sink, lens and short wiring harness.
They have 810 nm cluster !
With cluster like those , your car will appear brighter than sun
to the laser's eye :cool:
As for the patenting of a digital pulse rate. I am willing to bet I am okay for fair use to build something for myself and don't share. But the question is if the claim by the manufacturer is that this is encrypted data coming from the gun data. they may have a case.
this smacks of the same sort of thing DVD decrypters have gone through in recent years, and lawsuits flew out the doors like the wind. so .. who knows. the schematics of the finished driver and heads , that's a given. so I suppose I could give that away and let people find their own PPS rates.
As for the Leds, the ones I am using are leftovers for the illuminators I used to install in my other work . so it was a no money out project. the PIC controller is the most expensive item in this build (5 bucks) . The leds are 220mw 880nm. To put it in terms of what I have seen in other expensive units, I am right now 15X brighter with just what I have. (in IR terms, one of these leds is as bright as a mag light flashlight)
Again it means nothing till I test and test various generic jam rates. I may be completely off track as I don't have a spectral meter to test and see what the professional heads are putting out. As for the guns it also depends on their Ir receivers. If the slice of the IR spectrum pie they see is very very slim I may have to go to laser diodes to have the level of impact I want.
However I cannot see a lidar gun Mfg doing this due to drift in output Nm over time and age with the gun. filter too much at the aperture and you risk blinding yourself some. also there is the matter of detection distance and laser output. you would have to throw out a hefty Death star beam to get enough back to overcome IR clutter and other sources in the Nm you want.
While I don't really expect this to work first time out . it may make a nice hobby over the next few months to see what can can be achieved on the cheap
Solion
You're safe there as nothing from the gun is encrypted. The light pulses contain no data. Each pulse return is measured for time (distance) unlike radar which measures speed through a Doppler shift. The LIDAr gun then compares the distance between two or more pulses and computes speed from that.Quote:
Originally Posted by Solion
why don't you replicate what the LE-10 did, pulse them really fast in the KHz range (if they can handle it), yes you will get jam codes on the guns but you can't expect not to on a home made jammer. Basically make a brute force jammer out of LED's. I'm not sure how high you have to go but I would say at least 2000 times per second is a good starting point.
As long as you don't sell it, you might be able to use these patents to see how they did it.
lidatek - Google Patent Search
I have 3 lidar guns if you want to test your jammer. Let me know and I'll be glad to help with the testing.
Sounds like a plan then, as soon as I get back from my next convention I would love to take you up on that offer, I plan to make another set of jammer heads on the "hey look its the SUN!" principle (10 watts dead on the 905nm)
I could just brute force it. Thats a real possiblility. however the class of leds I am working with top out at about 1khz. and the trick here is the "el'cheapo beats the expensive guns" I promised myself I would not go over 50.00 in parts and see what
happens.
Right now I have a couple sweep programs that spin up and down from 40 to 500 PPS , 30 to 450 and 60 to 550. plus a whole shedload of different rates of those sweeps. Ill pick the top 10 I think may work. I am looking to try and force error codes or just to prevent lock.
If it turns into a complete EPIC FAIL to generate error codes with with fancy pulse sweeps and stuttering
then i will just retool to the higher end IR leds and give it a go again at a sweep between 1k and 2 k
So I am all for getting together for a test perhaps after thanksgiving. thanks for the offer
Solion
yup, brute force is basically the only way to go in a home made jammer, anything else requires too much work and money and you would be better off just buying a jammer. Maybe you could over drive them that high for a short period of time without them burning up, that is what lidatek did, that is why they only jammed for 5 seconds.
It will be interesting to see how this works. Brute force worked for the LE-10.Quote:
Originally Posted by Solion
I think all the pulse rates on the US lidar guns are between 100 and 400, but some here smarter than I can say for sure.
Sweeping pulses at those rates would possibly jam the Jenoptik LaserPatrol (and clones) with an E14 jam code, but it won't have any effect on any US guns. I'm sure you'll have a lot of fun testing it out though :)Quote:
Originally Posted by Solion
I think it will be as well. I can program the PIC with alot of different rates and see if anything works. It all depends on how much time I have. I may bring the lappy to program it on the fly and see if any of my IR madness sticks. But I think I am just going to run the "best outta 10" so I don't take up this guys whole day.Quote:
Originally Posted by jimbonzzzSweeping pulses at those rates would possibly jam the Jenoptik LaserPatrol (and clones) with an E14 jam code, but it won't have any effect on any US guns. I'm sure you'll have a lot of fun testing it out though :)Quote:
Originally Posted by Solion
The driver I have right now (if the leds could take it ) could drive as high as 10 khz and as high as 25v / 5 amps if I wanted to. so there should be a few options there if I have time to build the second set of heads for the HULK SMASH sort of jamming.
Do you have any suggestions on possible rate combination that might work?
Solon
Since you are using a pic maybe you could design a pattern that would be resonant at certain freqs and when you needed rates higher than 1K you could alternate multiple patterns of specific sets of diodes to get to 2K an above. You may loose some power but thinking from the suns point of view you may get away with it.Quote:
Originally Posted by Solion
You may get a pulse rate operating at some algorithm that could address multiple pulse rates of pulses per second at the same time. 5x400= 400,800,1200,1600 and 2000 pps at the same time. Slight variances could be more fun 4x500=500,1000,1500 and 2000 pps. And so on...
I am very interested in your project as I can see something like this being installed within the headlights and taillights for maximum effectiveness. Imagine receivers all over the car right where they try to get reflective speed :)
Same here.Quote:
Originally Posted by WRX STiMULi
Looks like you are off to a great start.
If you can post vids of the testing.
If they could be put in the head lights and tail lights that would be great.Quote:
Originally Posted by WRX STiMULi
But what about the reflectiveness on the outside of the lens?
well back in 2007 I posted here about making the socket housing for headlights a transmission medium. In a word, machining or casting in plastic IR Leds or laser diodes. as part of the socket assembly or a ring to go around the base of the bulb.
Sent Roy and others emails about my Idea with no response. all I really needed was an old blinder 20 or 25 to see how effective it would be. soooo if this works at all that will be my next step.
On another note, since I dont have my hands on a lidar jammer I am wondering about the JAM code and if there my be a little trick being played on us on how it determines a jamming source vs noise/lack of lock.
sensing cycle vs pulse cycle. I may be wrong in my guess but lets consider this as a possible way to determine a jam. that the sense cycle (for determining distance) is extended in a gap between pulse cycles while the laser is being fired. Now this part of the cycle does not happen till a timer error says 'hey still no distance reading" there may be a gap in a train of pulses inserted at that point where the gun looks for pulses that shoulden't be there. it sees something that is not random Ir noise. JAM
This is where I guess the expensive jammers may earn their keep. That when there is a gap in the pulses, The jammer is not putting out anything OR shows up as noise.
But I could be talking out of my ass , I have no clue without taking one apart
Solion
Fun stuff.
Solion
If all goes well this weekend I should have a Blinder 20/40 controller unit to donate for a period of time. I hope that some one has a Blinder 20 head they don't anymore to assist in your efforts.
I will post a thread to see if it draws any products...
http://www.radardetector.net/forums/...tml#post637829
I think the Lidatek switching frequency is in the MHZ range. This insures that a jam pulse is ALWAYS overlapping the lidar gun return pulse. More power to you and I hope the home brew system works, but I don't think switching at a few KHz will affect to much if its used as a standalone system.
Mating it to an older blinder head sounds interesting though.
Cool project. Those are HUGE LEDs you're using. Or you have really small hands. :)
What PIC are you using? I've done a few PIC projects myself. My latest is a laser tester that I currently have programmed with a bunch of different pulse rates, ranging from 100pps (Ultralyte) to 3.2KHz (some overseas gun), plus LA stealth mode. The timing algorithm I wrote can generate up to a 10KHz pulse rate with a 4MHz PIC.
As for patents, a pulse rate can't be patented (it's just a pulse every so many microseconds/milliseconds), no real data there. The patents are in the hardware and software design of the jammer, in particular the algorithms used to effectively jam guns without throwing jam codes.
Yeah that's another thing I was thinking about. I woulden't dare do it to a system still under warranty , but there is absoluty NO reason I cannot pigtail off of one of the LEDs in a blinder head with a transistor to run the massive 9mm Ir leds or laser driver with another power source.Quote:
Originally Posted by thx1138
It would be very cool if there was some tap point on some of the professional unit heads that would allow you to add on new IR arrays. I know for cars with large shiny grills that might be helpful.
Solion
[quote=WRX STiMULi;637828]If all goes well this weekend I should have a Blinder 20/40 controller unit to donate for a period of time. I hope that some one has a Blinder 20 head they don't anymore to assist in your efforts.
I will post a thread to see if it draws any products...
Thanks I really appreciate that. let me know what happens
Solion
Check your PMs as you have already had an offer on the other thread
WHOOT ( rubs hands together and cackles madly ) Thanks so much for your help!
this will be a real kick in the right direction
Solion
I am using a Pic18 I picked up few some years back. neat thing it had was a full USB supported interface for programming. I think You can still buy them for about 3-5 bucks now but there is allot better out there. the one I am using has a meg of flash on itQuote:
Originally Posted by kpatz
Solion
I just thought of something. Some part of me wants to call it the "Spyder system"
Lets take 1 Blinder.(check)
Take a handful of IR photo transistors or photo diodes (whichever they use) and pigtail out sensors for every light housing and possible "hit" point on a car.
Mmmmm me thinks this will be an interesting year
Solion
:)
Solion just touched on a thought I had while reading this thread.
First off, some background. I just finished a (partly successful) MIRT build involving 144 high power IR LED's, a constant current source, and a PICF184550 (plus a bunch of nice goodies like an LCD, etc).
My thought was why not use a photodiode as a receiver and use it to trigger your LED array. The key here is to appropriately filter the output of the photodiode to remove DC bias (from the environment) and external light sources. Since we know that the pulses we are expecting are square wave, a highpass filter with a high corner frequency should do. Stick the output of the filter to an interrupt pin on the PIC and have it pulse the LED for a short duration (couple mS maybe). Since there will be a brief delay to handle the interrupt (usually 5-8 instructions which = 3.5 uS) the LIDAR gun will receive two pulses for every one that it sends. The second pulse will be about 3.5 uS delayed.
It was my understanding that LIDAR guns take several samples for each distance reading. Since the gun now receives two valid pulses (the 3.5 uS delay equates to an added distance of about 500 m, which is within acceptable limits) it has to throw out that sample.
If you upped the clock speed of the PIC to 24 mhz (easily handled by the PIC I am using) you could return the pulse as quickly as .875 uS later for an equivalent added range of 125 m.
This is how I understood the ZR3 to work...
Actually for the test, I have hacked the laser trig from my old cheap laser/radar detector for for my jamming array. It gives me an isolated 1.43v to flip a transistor (2n4401) seemed to be an easy way to do it without having to design a detection circuit.
As for what you are saying about the delay. Yeah, that was one of my concerns as well, I think however I will probly drive the clock higher like you suggest. 3.5us may not seem like allot, But int he world of computing it's forever.
What I think I may do ( and still keep it under budget ) is setup a secondary array of IR photo-diodes that when hit will flip the jammer heads to an ultra simple 1kz pulser (always on) then roll back to the PIC when it executes.
However, before I do that I will be testing to see if I gain any success at all at jamming. short of the brute force 2khz omygodIamlookingintothesun I may be outta luck.
Really cannot wait to see if I can have any effect on Lidar guns. this really is the 15.00 and a soldering iron sort of project.
Thanks for the input
Solion
I've built a detector front end using the LT1328 IrDA receiver chip. So long as the photodiode has decent optical filtering for 900nm-ish peak efficiency there is very little noise. It is possible to make GHz bandwidth receivers with a few high grade, low bias current op-amps for even better detection. The 1328 gives a full scale output so it would be pretty easy to scatter a bunch of these detectors all over the car and trigger the jammer heads already installed on the car.
I wouldn't be too concerned about the interrupt handling delay. You want a certain amount of delay - its the presence of a second delayed signal that confuses the LIDAR gun. You just need to ensure that the delay is not so much that the gun can filter it out as a "jammer". My rough calculations based on 8 mhz would cause a secondary pulse to arrive 3.5 uS delayed which, based on the speed of light, works out to be the same as if the LIDAR was ranging a car that was an added 500m away.
I'm sure this is close enough that it will not be filtered out as Jammer noise.
Another concern is if the LIDAR detects the LENGTH of the pulse as well. If you are sending a 2 khz Brute-Force signal, what duty-cycle will you use? The advantage of using an IR photodiode and the interrupt pin is that you could trigger on the rising and falling edge - reproducing the source signal precisely.
UPDATE: Scratch that, research tells me that the LIDAR pulses are extremely short. On the order of a few nS! I think it is unlikely that the guns would do any sort of measurement on the duration of these pulses. Based on this, the interrupt handler for the pulse should be nothing more than turning the LED on and then immediately turning it off. This is good news; LED's can be overdriven substantially when run at low duty cycles. The duty cycle for a single instruction LED pulse (based on an 8 mhz clock) on a 1khz freq would be .05%!!!
An LED designed for a current of 100mA could easily handle 1A - substantially increasing it's output.
Right on brother. Im an engineer as well and this project intruigues me! I built an OBD-I reader with the help of other guys and love it!! I would be very interested in learning more and helping if I can.Quote:
Originally Posted by Solion
Im with an optical networking company that produces MEMS devices, CW light sources using laser diodes. We throw the things away by the case full due to hermeticity issues etc. Im going to dig around and find out the specs on these things.
What I dont understand is why you are trying to find a pulse rate? Why not swamp out the receiver circuit of the gun? Is it to avoid jamming notification at the gun? Your LEDs laser or not will always be brighter than the reflected signal.
I feel stupid potentially having throw away diodes that can build jammers. Im hoping they are closer to the 902nm that is needed.
Please keep posting on the DIY project! This is exciting.
The biggest problem with swamping out the receiver rather than pulses to trick it is the amount of light output required. You're broadcasting light out in a general sweep of an area to overcome the reflection of something which by comparison is more focused. I saw a web page, a little dated by still relevant which contained all the light output calculations and requirements for such a device and it can and has been done but its much more expensive and more prone to failures.
I'll see if I can dig it up, it was great article.
If you use delayed return pulses they'll have to be extremely close to the gun's returned pulse, as the gun itself only responds to the first returned pulse. So if the gun's own pulse returns before your jammer's pulse, guess what, the gun ignores your jammer's pulse!
You need to use an algorithm that anticipates the arrival of the next pulse (by determining the pps rate) and then sending pulses out AHEAD of the gun's next pulse. That way the gun measures based on your jammer's pulses instead of the gun's pulses and you can achieve a successful jam by varying the timing of the return pulses.