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Ask Slashdot: Wireless Proximity Detection?
New submitter Cinnamon Whirl writes "As a chemist, I work in a both lab and office enviroments, and need access to data in both, without causing undue clutter in either. My company has recently purchased two Win7 tablets for trial usage with electronic lab notebooks, propietry software, SAP, email etc. These are also useful for sharing in meetings, etc. As part of this project, I have been wondering whether we can use these tablets to detect other devices by proximity. Examples could include finding the nearest printer or monitor or, perhaps trickier, could two roaming devices find each other? Although lab technology is rarely cutting edge, I can see a day when all our sensors and probes will broadcast data (wireless thermocouples are already available), and positioning information will become much more important. What technologies exist to do this? How accurate can the detection be?"
See the Wikipedia entry on Bluetooth. Listed in the use cases for 4.0 (otherwise known as Bluetooth low energy):
"Mobile phones, gaming, PCs, watches, sports and fitness, healthcare, security & proximity, automotive, home electronics, automation, Industrial, etc."
If Wifi damages sperm quality, is it wise to use it heavily in a lab with highly sensitive experiments going on?
Bluetooth is a good option, also look at RFID. There are RFID kits that are windows compatible. Check it out and hopefully this will help get you started as to some of the possibilities. http://www.trossenrobotics.com/p/RFID-experimenters-kit.aspx?feed=Froogle -cluge
"Science is about ego as much as it is about discovery and truth " - I said it, so sue me.
you can use arduino with ultrasonic range detection (serial monitor), accurate as 2mm, I hope thats enough, but beware, maybe costs a bit higher than you think.
I always just take a look at my router page to see what devices are connected. And most of the time most devices will already have software for searching for other capable networks. Maybe you could just have the routers log emailed to you regularly.
In what way is your tablet making wireless use of a monitor? Are you talking about a computer workstation, or just a standalone monitor?
I can't see ad-hoc networking being very useful for instrumentation. I would think you'd want sure fire, dedicated, reliable data capture and not random hodge-podge as far as that goes. For example, an instrument in the lab finds Tablet A and dumps its cached data to that tablet. The user of Tablet A promptly leaves the building and the data is now stuck on his device which is out of range. Worse, Tablet A is then dropped in a stream of molten lava in the field, and the data from that instrument is lost for good.
I think you need to better define exactly what you're even wanting proximity detection for in the first place - specifically, when two devices find one another, what is the point? Printers are one of the few things that makes some sense for proximity, but even in that case, how many printers are you talking about that it is too tedious to pick the desired printer from a list? What if you don't want to print to the closest printer, but the one nearest your office? Or the printer back at the office while you're out in the field? I would think printers in a lab would be part of the infrastructure, and not an ad-hoc wifi network. Further, you're usually better off with your tablet connecting to a WAP and accessing the LAN, instead of trying to wirelessly connect to individual devices like printers directly. In that case the whole concept of proximity is out the window unless your talking about PAN (bluetooth) type peripherals like keyboards and mice.
WAPs are usually strategically located for maximum wireless coverage, whereas things like printers and instruments are situated in entirely different locations where they are easy to reach (and thus suboptimal from a wireless perspective). Proximity could actually be a bad thing - it is really just a restriction. Wouldn't you want to be able to access a specific instrument whether or not you were in direct wireless range of that device?
Better known as 318230.
There are two ways to use RF signaling to gauge distances.
The easy (but not at all accurate) way is to use signal power, relating higher received power to closer proximity. This method is very inaccurate, as the shortest path might not be (in fact, probably won't be) the path with the least attenuation. You can do this sort of thing in a wide open space, but in an office environment it's likely to be all but useless. It gets even less accurate when you introduce mobile devices, since the antenna's orientation is likely to be changing depending on how you hold it, which can vary received power by several decibels.
The better way is with timing, similar to how GPS works. However, you still have the "shortest path != least attenuated path" problem. For example, consider a signal that follows two paths to reach the receiver. One travels 100' and experiences 70 dB of attenuation, the other bounces around a wall instead of going through it, and ends up traveling 150' while only experiencing 60 dB of attenuation. After ~50 ns, the signal from the first path (which accurately represents the distance) will be swamped out by the signal from the second path. In order to get the info you need, you have two options: Either use a very high throughput signal (>1 Gbps) or have a special receiver architecture that recognizes those first symbols were an earlier path of the received signal and notes the time at which they arrived.
As a few has already mentioned, Bluetooth is an appropriate technical solution to the problem described. However, the environment you propose for this to be implemented suggests compliance with cGLP (current Good Laboratory Practices). In that case, whatever technical solution you implement will need to undergo qualification/validation to various degrees. This is somewhat more involved than finding (or slapping together some code of your own to create) an app to run/manage your equipment. If a potential vendor's offering has not already been certified, you're looking at extensive software testing/auditing in order to show compliance. My background is pharmaceutical manufacturing, so I can only speak to the availability of tools/resources that are compliant with FDA guidelines to that end. Given what is at stake, the validation process I was involved in was rather tedious and expensive. It would be wise for you to have your regulatory people speak with those who control the purse strings to determine exactly how much is necessary.
========== "Hello World" in my programming language of choice: ATG - LET THERE BE LIFE - TAG ==========
Windows 7 tablet? I didn't know they made them.
And your whole company, and whatever Microsoft "partner" organized that crap.
If you actually needed a wireless client device with easy data entry, you would not use 2indows 7 "tablet".
If you wanted something useful out of your handheld devices, you would have access to printers and other devies IN SPECIFICATIONS. But then, you would not be able to sign an extremely expensive contract with whoever is supplying Sharepoint-based applications for your system.
Contrary to the popular belief, there indeed is no God.
http://en.wikipedia.org/wiki/ZigBee
Lower power and cost. Suitable for sensors, but unlikely to see it integrated into tablets or netbooks though.
While seeing the closest is a tempting thought experiment, it may not be a practical solution for your actual workday (nearest printer may be low on toner, you may want these results in someone else's hands, etc). I'd still recommend what we do in our hospital by setting the shared device name with a zone number to indicate where it is. Your idea would be a great application for an RFID system with a map feature. Anyone have an idea with an existing app?
wait what? beaming proximity data over bluetooth does not mean that bluetooth can naturally act as a proximity detector
Problem solved. They are in close enough proximety for a blue screens of death tango.
Get a real tablet. iPad 2, Android Galaxy.
Sometimes I think all computers should have autocorrect...
...Is the only way to do it. Not 100% accurate but it can be done.
I'm not entirely sure how my employer does it, but depending on what lan port or wireless ap a computer/laptop is connected to will set up the correct printers for the office floor.
It sounds like you want a Local Positioning System. Not available as an out-of-the-box solution yet (AFAIK), but will probably become popular within the next few years.
There is a really lame commercial with some mock do-gooders who recover an elderly ladies purse, then charge her for their services. Not surprisingly, they are using Windows mobile device, and print her invoice on the nearest printer.
If your lame-ass tablets don't do what the commercial says, toss them and get an iPad or two. Rendezvous/Bonjour/mDNS, as they say, "just works", without embarrassingly sophomoric ad campaigns, or blatant astro-turfing like your query.
If tossing them isn't an option, root them and put a compatible distro on them. You'll never be happy with windows.
It sounds like what he wants is wireless, bluetooth, or RFID readable sensors. If the lab employee is near the sensor it can display the data from the sensor on the tablet. Still doesn't address reliable recording of that data, although they are likely manually recording this data on notebooks already.
yeah because chemistry labs are full of bluetooth wardrivers.
retard.
Just have a look at http://sourceforge.net/projects/blueproximity/ (mac), http://www.daveamenta.com/products/btproximity/ (windows), http://blueproximity.sourceforge.net/ (linux). This will detect you when you walk by with your bluetooth device. You can trigger actions as desired when in range - http://hints.macworld.com/article.php?story=20091221173111783 . There is even a commercial alternative - http://themha.com/airlock/ .
wait what? beaming proximity data over bluetooth does not mean that bluetooth can naturally act as a proximity detector
These guys have been disagreeing with you for several years:
BtProx - Bluetooth Proximity Lock Utility
Bluemon
You never had your keyboard hijacked from 10 feet away?
Or your mouse?
Obviously you don't think.
It was a neat idea, since soda could be ordered from the vending machines over the local network, to build a robot to deliver them. Despite the advantages of a first-tier engineering college, the problem proved intractable. tl;dr warning here be dragons.
This sounds like a solution looking for a problem.
If you have a sensor then the data is important, and not just when you are looking at it with your eyeballs. Most likely the data will be logged in a data logger, historian or LIMS database. Whether you use wired or wireless sensors, you've not just going to throw them into the feild randomly - each one will be individually configured in the database and given a meaningful name/identifier. Transmitting proximity information is thus irrelevant for data storage and analysis.
The only time I can see proximity being handy is if you were walking around, and it really just seems like an overcomplicated gimick. If you cant fit enough information on small/cheap local display, then you can wirelessly connect back to the datalogger/historian with your tablet and get a chart/trend/report of those named sensors.
I used a similar Bluetooth setup in my old house with my phone system.
My VoIP setup had multiple outside lines (up to 12, fees were for usage), and numerous internal extensions.
I tossed some scripts together for my computers around the house to watch for the bluetooth signal from my cell phone, and routed the call depending on that data.
If my cell phone was in my kitchen, calls to my main # got redirected to the extension in the kitchen.
If my cell was in the bedroom, calls got routed to that extension instead.
If my cell was no where to be seen in the house, calls to my main # were forwarded to my cell phone number, under the assumption I was not in the house.
This saved me from using my cell phone battery while inside, but when I was out calls routed to me none the less with no configuration changes, or having to remember to flip some switch when leaving and returning.
It was pretty neat to have the phone in the family room ring once (as I was already walking upstairs) and have the ring "follow" me from there to the kitchen extension and finally to my bedroom before answering.
Behind the scenes it was a mess of asterisk configs/scripts, shell scripts, and some wrapped TCL executable for the windows machines.
But it was fairly straight forward work, not too difficult. This should be very doable as long as one has a little bit of programming (or really even just scripting) experience to glue all the bits and pieces together.
...these sorts of technologies in the labs: wireless is often overrated unless you really need it.
It makes sense for your tablet. It doesn't make so much sense for that balance that needs to be leveled and calibrated anytime you shift it an inch anyway. Just use reliable wired connections for these sorts of things.
That doesn't mean hooking up a wire to your tablet. If the balance is wired to a network, and your tablet is wirelessly connected to a network, then they are already connected.
And, for any kind of serious data collection you don't want the instrument directly talking to a tablet anyway. The instrument should be talking to a server somewhere that is always running and capturing data, and then your tablet can connect to that server when it needs data. Oh, and if you're at home you can connect to it as well that way.
I can't tell you how many installations I've seen where some scientist got some money to have some consultants set up some kind of fancy data acquisition system in their lab. Inevitably it stores all its data on some PC that has no backups of any kind sitting in the lab. Of course, chances are the reason that they did it that way was that they're used to people in corporate IT just impeding progress, so they work around them. The right solution of course is cooperation - let the consultants handle their software and instruments, and have corporate IT provide the secured servers that they store data on. If your IT department is really sharp maybe they can actually help you work through what kinds of data is being collected where and help get it properly connected so that you aren't drowning in excel spreadsheets on flash drives.
However, all of this is a pipe dream. Small companies often don't have the resources to do something like this right, and big companies usually have managers who are too interested in their own empires to exhibit the kind of cooperation that I describe here. So, everybody micro-optimizes their piece of the puzzle and crosses their finger that there isn't a fire.
http://www.aeroscout.com/tags
http://www.ruckuswireless.com/
t-shirt for that. Why reinvent the app? http://www.thinkgeek.com/tshirts-apparel/interactive/991e/?cpg=clrss
I think you're missing the point of what he is asking. Redesigning all the devices in his world is not an option; he needs to do proximity detection across multiple wireless protocols. You know, it's this approach that gives geeks a bad name. "Oh, that's easy, just make EVERYTHING use [new unreleased technology that isn't even available yet]!" Yeah...in the real world, you have to work within the less convenient reality that you have to buy off-the-shelf, and that you don't get to design the entire universe as it would need to be in order to make solving one specific problem easier.
For your security, this post has been encrypted with ROT-13, twice.
Bluetooth's security is terrible, even in version 4.0. If you use it for proximity detection, it would be easy to mess up the transmission (e.g. injecting new devices, removing existing devices, etc). If you also use it to transmit sensor data, all values can be altered.
I realize that this probably doesn't matter in the particular case described in the question, but I imagine that a lot of people might try to find solutions to their related problems in these comments.
You could just install a WiFi base station in the middle of every room on very low power (using OpenWRT or another hackable firmware) and depending on your location have a web server or application that shows you only the instruments in that location (given they're connecting through the network as well).
Another trick is simply to use GPS. iDevices have GPS in them, most Androids do as well. I don't know what systems exactly you have but most tablets have a GPS optional or put one in a PCMCIA/ExpressCard slot. Then simply map your lab on the GPS and you should be able to figure out very exactly what room you're located in and again with a custom application or web server that reroutes you to the closest printers.
Another option but not commonly available for scientific instruments is to only use Bluetooth but you would have to locate all devices in the middle of the lab for them to be usable and it's expensive and not very reliable.
Custom electronics and digital signage for your business: www.evcircuits.com
Location-Based Naming Convention that includes building, department, room, window/desk id can achieve this with a custom program and basic assumption of access point location. Good asset management may be needed for screens. If the tools you are using can't be programmed against or automated, your best approach may be to have an internally-hosted lookup chart and have the mobile users just reference that.
-Tres
Different vendors have different levels of support of "location services." I know Cisco at least sells a location add-on to its enterprise lightweight AP management system.
However, from the limited amount I read about it it didn't strike me as being oriented towards allowing users to see their own location, or scripting based on location. Mostly it was aimed at access control and letting security-oriented personell (and PHBs monitoring bathroom breaks) play big brother. So there would be quite a bit of local customization work involved.
Someone had to do it.
This guy made some fancy proximity detectors for a wedding: http://www.instructables.com/id/Proximity-Sensing-Pocket-Squares/
It relies mostly on RSSI to get a coarse grain approximation of distance.
Would you mind throwing those up on Github or something so Google can index it for those of use who are interested in doing that ourselves?
Thanks!
futurlec or sparkfun... all sorts of cool geek gadgets there, even if you're completely incompetent with a soldering iron, like me
if you can't see the circuit boards, its just not cool
I'm interested in this myself. I see that most people respond to the example given, and not the question. Let's try to suggest some solutions without second guessing the application of which we have a limited view. My interest flows from the fact that Android running on my phone does not support wireless hotspot roaming. I have 3 hotspots in my home, but none of them on their own covers the whole house. So during the day I will have my phone on the wireless, but then at night I will lose connectivity while the phone is in the bedroom, or vice versa. I've adjusted the wireless power of the hotspots so that the phone loses connectivity and then searches for another hotspot, which works for the two locations listed, but it also means I have a ton of deadspots in-between. I'd like to solve the issue from the router side, by measuring the signal strength to the phone at some interval, and forcing a reconnect when it's closer to another hotspot. I know this solution means any current data connections will be severed when I transition, and I know that the issue may be bypassed by getting a stronger antenna. I'm doing this as a hobby / professional interest, so no cheating allowed. ;-)
Any ideas welcome.
Citation needed
Depending on scale, access point MAC might do the trick, or you could use signal strength and MACs from nearby APs to triangulate position.
I don't know about you, but my most sensitive GPS (of several) gets in in-building resolution of about 12 metres.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Wifi really does damage sperm quality. If a lab is performing highly sensitive biological experiments then blasting it with wifi on high-beam might not be such a good idea.
This has to be the ultimate Slashdot question. On other fora, I think devices just follow their...um...BIOS.
"What technologies exist to do this? How accurate can the detection be?"
you can use older bt tech too. the range is the kincher, really. or just use nfc, but then you might be just be able to detect that the device is on top of the other device. the whole question is stupid if they have a lab etc, they should have info already about available tech - though the question is posed more like "is there sentient magic that we could use?".
(and if you need some wild ideas, how about using ultra or infra sonic?)
world was created 5 seconds before this post as it is.
There's now an iPhone / iPad app for finding your car _even if you didn't remember to start the app when leaving your car_. It uses Bluetooth 4.0 and a tiny transmitter in the car. So the iPhone or iPad will detect when it leaves the proximity of the transmitter and record the location. (It could of course detect when you get near to the car as well, but it is pointless for that app).
It's a very tough problem, but positioning can be very accurate. These guys are doing it:
http://www.locatacorp.com/
My company also does it but a weaker version of 'it'. OTOH we are way cheaper and work with commodity off the shelf hardware.
I use ipads for my system. Its an engineering outfit but the same principle applies as we need to access data on the go and keep it all synced. I use pdf forms and webdav syncing to handle the complexities of syncronized data entry and python scripts to handle database, archiving and other tasks. I then use filemaker as a shared database system to provide highly granular access to data based on user roles and vpn + radius for remote access for engineers who are off site.
There were some initial problem due to the use of COTS products but iOS developers tend to be open to suggestions on feature requests and they were quite helpful for informal support as well. The whole system cost 6000 euros and around 80 hours over 10 weeks to develop and deploy.
Put a sign on your back and wait for a hacker to find you. You'll have no problem finding other devices that want to connect with you.
look at national instruments and labview
For ipad/phone/andyroid
The Data Dashboard lets you create a custom and portable view of your National Instruments LabVIEW applications by displaying the values of network published shared variables and/or web services on charts, gauges, text indicators and LEDs.
I didn't see it listed, but there are several freeware programs available, to show the location of and approximate distance of a wireless broadcaster. Several times, during vacations, I have used free wireless, being a miserly type person, and on an allowance. They are from the windows vista era, so work well with the win 7 enviroment. There is one even approved by microsoft to use as an app, by zerus(?) (called radar), that works really nice, listing all broadcasting devices nearby. the channel they are on, and the approx strength of the signal.
They can find each other, then you just have to set permissions to allow sharing, Then encrypt you whole system after the setup to make it secure.
Paradoxically, high power does not automatically give long distance since it is usually coupled with modulation for high data rates. For device discovery low power with low bandwidth modulation techniques can give greater range. When you want to send data, switch in a LNA and change the modulation for faster rates.
Many 802.15.4 systems on a chip can do these things at $5 a pop; e.g. 250K to 2M bits per second, switchable 20dB amplifier, switchable antennas. It is just a matter of writing the software. Probably wifi and bluetooth also have such capability.
Agree that signal stength or LQI is no indication of distance indoors. Maybe the existing and proposed sub GHz bands would improve that, I only have experience with 2.5GHz. Fixed devices can report their location, "Fourth floor skunkworks chromatograph", but "Joe's laptop" is less informative.
Seconded! This is one of the coolest hacks I've heard of on /. for a good while.
It is awkward for lab workers to have their mice hijacked, and even more so to lose control of their monkeys.
Always mount a spare monkey.
Check out this old google tech talk:
http://www.youtube.com/watch?v=6PiMimSrP7A
The old fashioned way? Why not have all phones ring in the house at once and pick up the phone nearest to you?
I've had call forward no answer, ever since... Say 1998 and it works great. Home phone rings 4 times no answer and the phone company forwards it to a number of your choice. You can even remotely change the forwarding number. It is one of my free options.... Works well. No need for a bunch of computers with multiple lines and lots of shell scripts.
There used to be an old yarn about being an engineer at Apple. If you were on the elevator and happened to be lucky/unlucky enough that Steve Jobs stepped onto the elevator with you, by the time the elevator reached your floor you would either have been promoted or fired. Whether true or not, it was very well known that Steve Jobs was very tough and demanding on engineers. He would routinely prowl through the engineering departments to surprise people with spot checks.
For creative people, this kind of intrusion can be very disruptive -- even the possibility can keep someone from entering "flow state", the scientific term for a mental state creative people enter when they are at their most creative and productive. This in turn, creates a great deal of stress on an individual.
So, a few years ago, not long after Apple added Bluetooth to their computers, another story began to circulate. Jobs started noticing that his surprise spot checks didn't seem to be as much as a surprise as he thought. Engineers would be conveniently on a coffee break, stepping out to go to the bathroom, etc. For some odd reason or another, they just wouldn't be at their desks when he thought they would be. It wasn't just engineering. The effect began to spread to other departments in the company. Jobs began to suspect something after a while, but couldn't quite put his finger on it.
Eventually, the "something" became so widespread, that it was due that someone would slip up, and Jobs discovered what was going on. One of the engineers wrote a program that would listen for the bluetooth transponder in a cellphone and query its serial number. Then, by propagating the program onto computers throughout the company, the system would track Jobs by the serial number of his cellphone via bluetooth. Every time Jobs walked past a computer with the software on it, the computer would send out a signal showing Jobs' position within the company, and that was displayed on a window on any computer listening for the signal. This way, engineers knew when Jobs was on the prowl, where he was, where he was going, and they would know when to clear out to avoid getting blistered by the boss!
The legend ends with Jobs ordering that the software be removed and the engineer who came up with it was given a raise for creative thinking outside the box.
Are there any Apple engineers out there that can prove or disprove the validity of this tale? I did a quick search on Google, but came up bupkis.
Whew! This water sure is cold!
You should read Apple's spec for Bonjour, their implementation of Zero Configuration Networking.
I'm curious how this really made it to "Ask Slashdot" when a quick Google Search shows that this kind of tech has been around for some time (though not always setup or implemented well).
well thats all great and fine and good but the use of bluetooth in this MESH NETWORK is purely convenience it could have been any radio system, and I still stand behind my original statement
buzzword or not having a transmitter on you does not make it an instant proximity detector, you could make it into one like above using a mesh network, or you could triagulate it, but it doesnt fucking matter if its bluetooth, wifi, xbee or a fucking AM radio source playing Hank Williams
mount: wrong fs type, bad option, bad superblock on /dev/monkey91, or too many mounted file systems
And they told me that this is where AIDS came from... pfft!
Bravo. Best lighthearted comment i've read all day.