How about a combination of RF and ultrasonic? RF will go on and off around 50ft unreliably. Sound will show when you're within 20ft. Less than that you can use the ping (sound) idea?
That might work. I was wondering if there was a way to use a separate ultrasonic sensor and transmitter. That way the "anomaly" is just an ultrasonic beacon, and the detector picks up the pings from it. A traditional ultrasonic rangefinder wouldn't work because theres no way to know what the sound is bouncing off of. Thats why I was thinking of using a separate transmitter and detector, and using either a RTC module or RF "packet" to sync the time between them. Ben heck did something like that for the luggage that follows you:
The player doesn't need to be able to differentiate between anomalies, they just need to know that there is one "nearby". If those RF modules have poor range, that would be perfect. The anomalies will be static, and placed by refs, so they will be set a few hundred feet apart, or more. The anomalies will also most likely be separated by some pretty RF hostile territory (thick trees, brush, swamp), but the detectors will be in the same clearing as the anomaly.
How would I get different range from different antennas? Would it be as simple as having an antenna outside the detector's box that could pick up the anomalies from much farther, and one inside the box that would only work at closer ranges?
people are much politer when you know every person is packing heat
and an interesting point about murder rates
Texas is well known for their love of guns and their willingness to use them
New York is known for having some of the most restrictive gun laws in the land
and they are both at the top of the list, lead slug or lead pipe, crazy gonna kill
I think Texas shows up because the statistics do not separate murders from self-defense. They also have a lot of drug and gang crime due to their proximity to Mexico, and a large section of the US border. California really stands out with only 21.3% gun ownership, yet 1,257 out of 1,811 murders involved a firearm. Most likely also gang related. The most interesting statistic is D.C, where it is illegal for a civilian to even own a gun. Lowest gun ownership rate in the country at 3.6%, highest gun murder rate per 100,000 people at 16.5 (also highest murder rate at 21.. Thats more than double the next highest state. You would think with all the bullets flying around there, they might manage to take out one or two of our corrupt politicians.
Yeah, that requires access to the OBD port on the car, he even says "thieves have ways to get into the car, we can't show you that part". The car thieves I am talking about are often misidentified as the car owners, because they just walk up to the car and enter it. There's no fumbling around programming a new key. They have also hit cars that are side-by-side, so its unlikely that they were hit by a shady mechanic that made a copy of their key.
guns don't kill people, people do, and if they don't have a gun they'll have a knife or a base ball bat... Cars can kill people too!
Bottom line in my opinion, the mental health system needs to be shaken up, you don't catch Gangs going into schools and shooting kids, infact gangs don't interfere with any law abiding citizen unless you get in their way or start a fight with one, so yes outlaw guns and only outlaws will have them but that's true for every major city on the planet!
It's the deranged people who have *access* to guns that concern me, and with total gun control, these crazies simply can't go into schools and parks and shoot people, obviously the determined ones who have a point to prove will, but again they fall under the mental health issues.
I'd love to see someone give me an example of where Guns are *bad* not involving a mentally ill person (Gangs, tend to target other gangs...)
I agree, Its a people problem, not a gun problem. The numbers show this. There are countries with higher rates of gun ownership, and less crime, and there are places with lower gun ownership and more crime. I live in a state with a very high number of guns per person, very lax gun laws, and very few murders. You can freely walk down the street carrying a gun in my state. There is no wait period for purchasing firearms or ammunition. There are no permits, licenses, or registrations required. There are no laws against private transfer of a firearm (you can even mail them to another person within the state). You can set off up to 40lbs of explosives legally, with no licence, "for recreational purposes". I'm legally allowed to step outside of my house and start target shooting (and many people do this in my area). The minimum age for purchasing a rifle was changed from 16 to 18 in the last 12 years.
Number of people murdered in my state last year: 24 Number of murders involving a gun: 11
The places with high numbers of gun crime tend to be places with a lot of violent crimes. Get rid of the gangs, and switch to a healthcare system (instead of our current disease management system), and we will start seeing homicide rates more in line with the first world. Banning weapons wont stop Americans from wanting to kill eachother. There are only four problem states in the US: Florida, New York, Texas, and California. They all have more than 800 murders per year.
I watched a small segment about this on TV the other day.
What they do is is lay in wait for a person to arrive home, switch on a jammer and the electronics can't pick up any signal from all the noise, the victim gets out and proceeds indoors the thief then jumps into the car, does what he needs, plants a GPS and waits.
The thief then tracks the vehicle or (going by what i remember) gain access to the car some other way (once inside the car)
I don't think it could be either of those methods, as these criminals would just walk up to a car, put a device near the passenger side door, and the doors would unlock, and lights would flash. The jammer wouldn't make the lights flash, and the spare key programmer required them to break into the car the normal way first. I still think the relay hack is the most likely.
I was hoping too. Just the thought that someone with a portable antenna walking around my building could steal my car is scary.
What if you de-solder one of the legs of the battery holder, and wire it to a simple tactile button on the back of the keyfob? Then just hold that button down to power on the keyfob whenever you want to use one of the buttons. I should patent this, lol.
How does noip.com find out if a dynamic IP has changed on the remote Arduino???
A client request is made to on-ip.com, which identifies the current IP address being used by the client/server.
I understand that no-ip.com has a Dynamic Update Client available for Windows, etc, but how do we do this with the remote Arduino? Have you written some code to do this?
Thanks and best regards
I believe there is a specific URL you can go to, so you just have the arduino make a connection. I ran into trouble with no-ip free though, my IP address didn't change for a long period of time, so they deleted my url and returned it to the pool. I started using http://freedns.afraid.org/ instead. afriad.org free DNS does have an update URL that you can use. It is available in your control panel.
I have been asked by a airsoft game operator if it is possible to create an "Echo Detector" for a Stalker, Shadow of Chernobyl scenario "cheaply". An echo detector is a device that alerts the player when an "anomaly" is nearby, and beeps more quickly as the player gets closer. So I will need to create both an "anomaly" device and a detector device. The longest range needed is approximately 50 feet (I think, still waiting on this information).
Since I havn't received any specific information about the prop, i'm going to break this into two steps. The first step is just to get the Arduino to detect when it is within about 50 feet of a device. The ideas that immediately come to mind are those cheap RF transmitter/receiver pairs that you can get on ebay for like $2, but i'm not sure of the range. There's going to be a lot of these devices on the field, so I don't want them interfering with eachother. Other options are IR, Bluetooth, and ultrasonic sensors. I don't think I could get GPS modules cheaply enough, or accurate enough for this.
The second step is getting some idea of how far apart the two devices are. The accuracy can be fairly low. If it could just tell the difference between max distance, 2/3 max distance, and 1/3 max distance, that would be good. To get an idea of the distance, the usual method is to send out a pulse at a known speed and see how long it takes to come back. I don't think the arduino microprocessor is fast enough to do this with RF or IR. Would this be achievable with an ultrasonic transmitter and receiver? I could use the RF pair to sync the time on the two devices, or a realtime clock if that would be accurate enough. Are there any bluetooth modules that can be queried for signal strength?
I'm probably going to end up building these below cost, so any help is appreciated.
I don't believe this type of censorship has any place on a technology forum. Guns and technology are tools, they are not inherently evil, and they do not cause harm by themselves. Their users determine the amount of harm or good, that come from them. Take the internet for example. Its an amazing tool that has linked the world together and allows for the free transfer on information. People in remote areas that may have never seen a library, now have access to the collected works of the entire world. However, the internet has also given the government's of the world a way to wage war on eachother with limited human casualties.
Look at GPS, the same technology that helps you find your way to a friends house, is also used to guide 40,000lb bombs to their target.
The same electricity that powers your computer, was used for electrocuting people to death.
NASA bought up a bunch of ICBM bodies and used them to launch.....atmospheric monitoring satellites, and communication satellites.
Old naval warships and submarines are routinely used as research platforms.
Nuclear power was used to destroy two cities in Japan, now it is used to provide 30% of their electricity needs.
Mortars, recoiless rifles, and artillery pieces are routinely used to prevent avalanches, saving hundreds of lives per year.
My own state uses M113 Armored Personnel Carriers to deliver firefighters and rescue personnel to hazardous or remote locations.
Censoring information is often pushed as "for the greater good", but there is nothing good about restricting information. It goes against everything the internet is. I am appalled that this is even a topic here.
They could use a wireless relay to trick the car into thinking the keyfob is closer. A second criminal would have to stand within 50 feet of the car owner/key, something that's not that hard for small city apartments or inside stores.
The video I saw showed the thieves being unable to break into a Ford and I think a Dodge? I believe they were able to get into a BMW. Another thing of note, none of the cars were stolen using this technique, items were just stolen from them. Even on vehicles with keyless ignition. So it seems they cannot trick the ignition system, only the door lock and security system. They also always used the passenger side door.
I wonder if it could be something as simple as some unscrupulous mechanics, garage employees, or valets using that BMW technique to make their own keyfobs, then coming back later.
All modern key fobs are supposed to use rolling, one time passwords, making this impossible. Thats according to the manufacturers. Its entirely possible that they decided it was cheaper just to use a unique ID and hope no one noticed.
Any ideas? There is speculation that they are using a transmitter to overpower some of the communication lines inside the car, but I would think a car would have some pretty hefty shielding to deal with all that noise. I'm wondering if they may just be using a high powered magnet to overpower the relay/lock solenoid. I don't have a keyless entry system in my vehicle, so i'm not sure if unlocking the car would also disable the security system.
You will also need an xbee explorer breakout board to make the RN-XV module work with the 5v serial lines on the Arduino.
I would just have the server save the results of that bash script to a file on the PC (using that method I linked to), then have a a little python script or something on the PC send a packet to the arduino containing the service state. The Wifly HQ library has an example that shows how to listen for a packet, and searching for "wiflyhq and python" shows you how to send the packet.
The actual lighting of the LED is trivial and covered in the playground and example sections of this site (its pretty much the first thing you learn how to do with an arduino). Thats assuming a standard 5mm LED, higher current LEDs require a little more setup.