905nM Laser Sensor

[fritz42_male]

Hi all,

Just wonder if any of you have come across any sensors that are specific to the 905 nM Laser frequency. I'm fed up of getting low level speeding tickets for accidental lapses and am looking at knocking up a basic sensor that would bleep in the event of detecting a laser.

Yes I know someone will say don't speed but you try it in WA - they are going to ridiculous extents to maximise revenue from tickets - got my last one as I was decelerating into a school zone - they pitched the trap just past the speed reduction sign. I've now switched logging and speed warnings on on my GPS but it only warns you of speeding on a few roads and I can't get the school zones list for my GPS

Thanks

Fritz

 

[Dippy]

A photodiode will detect 900nm and they come with all sorts of filters - go through photodiode specs frpm places like Farnell, Digikey , Rs etc etc.
Read up.

Surely if you detect a beam then it's too late?
It's not like they radiate all over the place like microwave.

Sorry, no sympathy, if you break the law then tough titty.
You should decelerate down to the correct speed before entering the zone.
I know it can be a pain.
Yes, I've been done before. Hands up , surrender, it's a fair cop Guv. Lesson learnt and move on.

 

[hippy]

It's probably better to buy a commercial detection unit as this will have been tested to work with the speed guns used; there isn't usually a lot of options for testing a DIY solution with real speed trap equipment without going through one

If commercial units are not available that's probably because they are deemed illegal in your jurisdiction.

Surely if you detect a beam then it's too late?

One theory is that it allows the driver to detect when they've trained a speed gun on the vehicle whilst still outside the limited zone so the driver knows they are being monitored and can slow down for the limited zone ( which they should be doing anyway ). If already over the limit it's probably of little help.

 

[Dippy]

Oh I see.

Are we meant to wear laser-filter goggles nowadays then?
I'd hate to be blinded -and I bet they are a little bit more powerful than the 1mW or 3mW that is commonly around

How wide are the laser beams they use?
How do I ensure my sensor gets hit?
Is it all a waste of time?

 

[manie]

Probably a wste of time....... I've slowed down naturally nowadays..... the little 1500cc car is quite happy at 120KmH on the highway and the fuel consumption is GOOOOD ! So why bother ? Here in RSA they only accept b--bes...... its the culture........

 

[SAborn]

In today's age of electronics i would like to see intelligent road signs that transmitted to the vehicle a speed warning, this would have a far bigger safety aspect than some over eager cop with his hair drier on revenue razing duty.

It is something i have discussed with other electronic minded persons on a method to achieve this. (any ideas here?)

With mass production of sign transmitters and small solar systems the cost per sign would be small.

As many of us now have a GPS device or similar in our vehicles the interface could be introduced without an issue, and I'm sure new cars would incorporate the system as a standard safety feature.

The amount of road signs in use here in Oz is becoming outrageous, to the point ones eyes are watching the pavement for signs more than the road.

If the powers were serious about fixing the problems rather than revenue razing than systems like this would be put in place in the name of safety, but as speeding fines generate $ billions of revenue, why would they want to kill off the cash cow.

 

[hippy]

In today's age of electronics i would like to see intelligent road signs that transmitted to the vehicle a speed warning

The UK has a simpler low-tech solution; speed signs which monitor approaching cars and warn those going too fast by lighting up "slow down" warnings and showing the required speed. Quite effective in influencing driver behaviour by most accounts.

The ultimate high-tech would be a system which knows the limit and either enforces it, reports breaking of it, or fines on the spot. I'm not going to get involved in any debate on the merits of that, but that's the sort of thing which is meant by "social issues" on technology curriculum.

 

[Dippy]

Yes, I have seen quite of few of those "Slow Down" and sign-post-speed indicators near me in (ooh arrr) rustic Dorset.
From casual observations they seem very effective.
I'm not sure how much they cost but I bet they are in the thousands.

"The ultimate high-tech would be a system which knows the limit and either enforces it,..."
- yup, it's called Gatso !


Yes, the argument in UK is also about using fines as a fund raiser.
Blame everyone except yourself is the usual recourse.
If you don't want to contribute to the fund then don't speed. Easy.

In UK Gatso (fixed ones) machines are
1. Painted bright yellow/orange.
2. Usually road marked
3. Numerous warning signs 100s of metres either side.
4. Co-ords listed on Internet.
5. Audio Warning on most vehicle/portable GPS.
In UK, if you can't notice all that lot then you are too blind to drive.

 

[papaof2]

The UK has a simpler low-tech solution; speed signs which monitor approaching cars and warn those going too fast by lighting up "slow down" warnings and showing the required speed. Quite effective in influencing driver behaviour by most accounts.

Those signs are in other countries as well. I did some PDA development for a company in the Atlanta, GA, area that builds these signs - including solar powered stand-alone versions. They wanted to use the IR interface of a Palm PDA to configure the sign (speed set point, type of indication, display brightness - including off when just collecting data, hours of operation, maximum displayed speed, etc) and to download the collected data (traffic count, speeds by time of day, number over speed, etc). They've since changed to a Bluetooth interface and no longer need me (sigh) It much nicer for the users to sit in a car on a rainy day and use a laptop than to stand in front of the sign in the rain for a couple of minutes to use the IR interface. The speed detector is a small radar unit with a microprocessor (programmed in compiled Basic the last time I saw their code) with a micro-SD card for data storage , plus some serious LED drivers to handle seven segment displays about 8" - 10" inches high (made up of very large individual LEDs). The cases are machined aluminum and "ball bat proof" - the LEDs are recessed behnd a clear panel to protect them. The ability to set the maximum displayed speed keeps people from using the sign as their "How fast will my car go?" indicator. In a 35MPH zone, the display might go into "flash" mode (flashing "--" or "88" or turning off) at 50MPH (or whatever the user chooses). The SD card gives the ability to collect data for long periods between visits for dwnloading, depending on amount of traffic and hours the sign is in operation. The last time I talked with them (couple of years ago) they were considering adding a cell phone module for problem reporting plus remote configuration and data collection. And you probably thought it was just a speed display ;-)

That company has some figures on how much speed reduction the signs produce on their site: http://www.radarsign.com/

John

 

[hippy]

I'm not sure how much they cost but I bet they are in the thousands.

Apparently cost around £5,000 plus installation, then annual electricity plus servicing costs which are around £1,000 per year, according to our local Police Community Safety Officer. So costed over 5 years that's around £6 per day.

Gatso's and similar cost £20,000 and upwards plus installation, higher running costs, but do recoup revenue or, more correctly, need to to be self-financing.

 

[Dippy]

Blimey, I made a basic one with a £3 dsPIC!

I'm in the wrong business again

 

[SAborn]

So whats the cost of a simple bluetooth module to interface with a passing vehicle to inform you that there has been a change of speed limit, in the case one has missed the sign.

My point is not for the go fast speeders but the average citizen that missed the posted speed sign and gets pinged by Mr. Plod with his speed gun.

We have for ever changing speed limits on average roads/streets here, there's the 25kph in school areas, followed by either or all of 40, 50, 60, 70, 80kph on and average road, miss one sign and Mr Plod has you.

We once had 60kph for the around town roads with the odd 80kph on faster flowing roads, simple and no real excuse for being over the limit, but 5 different limits on one stretch of road is a joke and also the Mr. Plod hot spots.

If the revenue raised was put back into fixing the problems i would not have such a problem with it.

 

[Dippy]

Changing speed limits is a Pain I agree.

But if a speed limit is not clearly signed then you can use that as mitigation (and win) in court.

Then with technology you'd get the whingers saying "Who's going to pay for my dongle? Not me, not me!"

I'd be very surprised if someone got 'done' for 35 in a 30 - especially as your average speedo is 5% to 10% fast.
I know there are some officious Constables about but I feel people are a little paranoid generally.
But if you can prove invalid / unclear signing then you'll escape.


My Tom Tom GPS allows nerdynet connection for road/zone speed limit updates (downloads).
Obviously I have to TRUST that someone has done it all correctly at their end - but then YOU would have to trust that little RF device on the side of the road.
Can you imagine the visits to court if that made an error or conked out?
For now, forget all that WIBNI stuff and keep your eyes peeled

 

[John West]

Police in Colorado USA are also in a money bind and are setting up all sorts of interesting traps. I was caught in one a couple of months ago.

They set up at rush-hour on a rural highway between two fair sized cities with a lot of commuter traffic between the two. They sat off on a side highway and watched for cars swinging onto the wide paved shoulder around the cars backed at a stoplight in order to get into the right turn lane.

Three of us pulled around an SUV that was just sitting there after the light had turned green (he was probably texting.) We were on the paved shoulder of the road for about two car lengths before the white line turned it into the right turn lane.

Didn't matter that the maneuver was small and safe. Didn't matter that the vehicle in front of us was obstructing traffic. The cop wrote each of us up for a $113 ticket.

The cop even seemed embarrassed by the trap. But I had to pay up nonetheless. It's the first ticket I've had in 30 years. I avoid them buy driving safely and legally. But this time they were lying in wait for a known situation where even a careful, reasonable driver could be tripped up.

It's getting nasty out there.

 

[Dippy]

Nasty.
Get a newspaper reporter on the case.
Embarrassment , publicity and humiliation can often cure a canker.

 

[Jaguarjoe]

Here's an interesting article about what's happening around the D in this regard:

http://detnews.com/article/20100427/METRO05/4270380/Many-speed-limits-set-too-low

 

[John West]

I was born and raised around Flint, MI, Joe. But I've been to Detroit exactly 3 times in my life. I'm hoping to keep it from ever reaching 4 times. Flint is bad enough. Detroit has become a national tragedy.

Sorry to be so OT so early in the thread, but the situation in Detroit is just sad.

 

[John West]

Nasty.
Get a newspaper reporter on the case.
Embarrassment , publicity and humiliation can often cure a canker.

I was contemplating a 1X4 with roofing nails driven through it, buried right where the patrol cars back in to hide. But as I'm a law abiding citizen I was only contemplating it.
However, I don't think police forces realize just how much respect and public support they lose each time they play highway robber. I told this story to at least a dozen other people in the last few weeks, and now I expect they all have a lower opinion of our "public servants."

But, back on topic...

 

[Dippy]

What was the topic? I've forgotten. Oh, detecting laser.
I don't think it's practical , it'll never get done. Just buy one, they're cheap.
So let's get back to designing a PICAXE based Stinger.

 

[fritz42_male]

Cheap? A Vitronic detector jammer will cost you about $800+

Don't speed? Last but one offence was for doing 63Km in a 60 and I was in a solid stream of traffic. They don't accept the 10% potential speedo error in WA - in fact one official was quoted as saying they want to make 1KM above the limit an offence.

WA police are required to generate substantial revenue from speedcams - I've seen cameras on motorway feeds and offramps. They are extremely underhand about camera positioning and it's usually in locations where they will generate greatest revenue - rarely on blackspots.

I have no problem with not speeding providing the law is sensible. I'm more than happy to have my GPS alert me or have warning signs or whatever but the GPS maps for WA have speed limits enabled on about 10% of the roads so a GPS won't warn you most of the time. Seriously, if you think the UK is overburdened with speed cameras then you ought to try WA - at least the UK police aren't sneaky about it (well most of the time).

Re the Detroit article - I love the way they say 'the community wants us to do this' - a survey of the community would probably result in a massive 'NO' to these situations. I would say that the best cure for safety is alerting road signs and accurate GPS maps. Especially put alerting and flashing signs in school areas.

Re the sensor, I'll take your advice though. As you said, by the time you detect it, unless you are jamming it's probably too late (unlike radar).

 

[eclectic]

snip

Don't speed? Last but one offence was for doing 63Km in a 60 and I was in a solid stream of traffic. They don't accept the 10% potential speedo error in WA - in fact one official was quoted as saying they want to make 1KM above the limit an offence.

WA police are required to generate substantial revenue from speedcams - I've seen cameras on motorway feeds and offramps. They are extremely underhand about camera positioning and it's usually in locations where they will generate greatest revenue - rarely on blackspots.

Assuming all the above facts are correct,
then how about mass action, rather like the French lorry drivers?
All of you join together and convoy
at say 58 Kmph


e

OR, adjust your brain by -10%
Whan you see a 60 sign,
drive at 54.

 

[fritz42_male]

Well we have already had 'road rage' attacks where an irate motorist will damage a camera. One of the latest developments is a camera that can get you for 5 offenses in one picture - speeding, arm out of the window (yes, that is illegal in WA how pathetic is that), dangly on your rear-view mirror, on the phone and smoking). Mind you, I agree with all of these apart from the arm out of the window - I see no harm in that.

I do think it will come down to pressure from motorists in the end. Maybe even give motorists the option of automatically limited vehicles.

Re dropping the speed automatically - I do anyway but sometimes my brain goes into automatic and I don't notice when the speed creeps up a bit. I drive several hours each day so I suppose it's one of the risks. I don't use my speedo anymore - I use my GPS to monitor my speed.

 

[Minifig666]

I'm still shocked that there still hasn't been a compusary device fitted to cars that allerts you or limits your speed depending on the zone you are in.
I'm not sure how arquard this could be, I don't drive so my opinions are null and void, but the only problem I see is if you needed to avoid a possible accident.

 

[Jaguarjoe]

I was born and raised around Flint, MI, Joe. But I've been to Detroit exactly 3 times in my life. I'm hoping to keep it from ever reaching 4 times. Flint is bad enough. Detroit has become a national tragedy.

Sorry to be so OT so early in the thread, but the situation in Detroit is just sad.

I haven't been on a "nonfreeway" city street in D in years. My ahole puckers up even when I'm on the major expressways just passing through.
It has more burned out or vacant land than the entire area of the city of Buffalo, NY, that's 52.5 square miles!

 

[papaof2]

Don't speed? Last but one offence was for doing 63Km in a 60 and I was in a solid stream of traffic. They don't accept the 10% potential speedo error in WA - in fact one official was quoted as saying they want to make 1KM above the limit an offence.

You need to get the manuacturers involved - I complained about the speedo in my Toyoyta truck reading 5% high and got the response "Factory limit is +/- 7%".

I take it the officials are appointed and not elected? The voting public is aometimes good about getting expensive annoyances out of office ;-)

Unless their radar has had recent calibration, it may not be capable of 1Km resolution. LIDAR on the other hand may stay in calibration better because it consists of smaller pieces mounted on a circuit board and less subject to alignment problems.

Perhaps you should run for national office on a platform of traffic reform - with a major item being jail time instead of fines for speeding. Jail time is very expensive for local law enforcement, so it's likely they'll only be after those at least 15 - 20Km over the limit.

If speed control is the issue (instead of revene) they could do what Nevada State Police do for people travelling from California to Nevada to gamble - they make a convoy with police vehicles in all lanes and interspersed with the convoy vehicles if needed. There's no way the drivers can go faster than the police vehicles - instant speed control ;-)

John

 

[boriz]

“as speeding fines generate $ billions of revenue, why would they want to kill off the cash cow.”

It’s happening right now in the UK. Some councils are removing speed cameras or just not servicing them because all the proceeds go to central government, but the local council is expected to stump up for all the running and servicing costs.

 

[fritz42_male]

There's no way the drivers can go faster than the police vehicles

Unless they are suicidal you mean.

I believe the inaccuracy of speedos was tested in court and the plaintiff was told 'you should have played safe'

Simple fact is that WA won't get rid of them in the forseeable future. They are already trying to ban alerting systems which proves conclusively that these are revenue raisers no matter what the politicals and police say.

As for running for office? No thanks. I'm not corrupt. I've always thought that the phrase 'corrupt politician' is a tautology.