Show HN: FIND – an indoor positioning system for smartphones and laptops

by qrv3w • 10 years ago

183 72 10 years ago

logibly• 10 years ago

Awesome, I wonder what this combined with some electronic automation can do. Eg, I walk into a room and lights turn on, i walk out, lights turn off (depending on time of the day etc).

pavs3• 10 years ago

Motion sensored room light has been available for at least 15-20 years.

zyxley3• 10 years ago

Sure, but with this you've got less hardware involved in total, and more flexibility for programmed responses.

fabulist7• 10 years ago

This is billed as a replacement for motion sensors in home automation. Though it does beg the question, "what if someone moves their router?"

glibgil• 10 years ago

At least sixty years http://www.google.com/patents/US2655645

laumars5• 10 years ago

Yeah, but do any of those motion sensor systems detect if a person is still in the room but motionless? Eg if you're sat reading.

I ask because Ive had to wave my arms about far too often in public restrooms due to motion sensors deactivating the lights when spending too long on the toilet. Having that happen in my own home would be annoying enough to warrant the additional complexity of FIND (or ditch home automation entirely)

magic_man• 10 years ago

Once finger printing has been done can that info be shared with other cell phones?

Sanddancer• 10 years ago

I don't see why you couldn't. You're just shipping serial numbers through the air at that point.

rasz_pl5• 10 years ago

devices have different antennas, in different places and with different orientation.

iamflimflam1• 10 years ago

Yes according to the FAQ:

"The WiFi fingerprints are also the same across all devices so that learning using one device is guaranteed to work across all devices."

https://github.com/schollz/find/blob/master/FAQ.md#doesnt-th...

qrv3w13• 10 years ago

Yes you can! Just share the "Group" name that you used for the fingerprinting.

fabulist7• 10 years ago

For those of you curious how it works, it's a parasitic radar system using the wireless APs of you/your neighbors to triangulate it's own position.

https://github.com/schollz/find/blob/master/FAQ.md#how-does-...

rasz_pl5• 10 years ago

no, its nothing like radar. it uses labels and signal strength.

RottenHuman• 10 years ago

And how does this exclude it from being called radar?

fabulist7• 10 years ago

https://en.wikipedia.org/wiki/Passive_radar

lhaussknecht3• 10 years ago

As far as I understood, it's not using triangulation. It's using machine learning to classify wifi fingerprints.

mikecb• 10 years ago

To map the area. And then it uses signal strength to determine relative location.

qrv3w13• 10 years ago

it's a parasitic radar system

That's an accurate description, though I'd avoid the negative terminology. The system does derive its data from nearby WiFi routers, but it is in no way exploitative, like real parasites. WiFi scanning is something all smartphones do all the time, so this system merely tries harnessing it into something useful at the same time.

As for the technical side - this system uses a Naive Bayes estimator for the signal levels from mac addresses, as well as the presence of mac addresses it sees during scans. Before it can be used it needs to "learn" by visiting all the locations you want to identify. After learning it "tracks" by classifying the location used the Naive bayes estimators.

fabulist7• 10 years ago

Parasitic is a technical term.

OrangeTux• 10 years ago

I've looked through the code to get a better understanding of this process, but I couldn't get my head around it. Could you give a more detailed description of this process?

zyxley3• 10 years ago

For this to replace motion sensors for home use, I think it'd have to run on an Android smartwatch, and one of the ones that's slim enough that you'll actually wear it all the time.

It still wouldn't work so well, though, for basic use cases like "turn on the dimmer lights to 40% if I enter the bathroom in the middle of the night".

qrv3w13• 10 years ago

That's an awesome idea! I'll look into that!

zyxley3• 10 years ago

The closest to 'ideal' would probably be one of those fitness band form-factors that can be and is intended to be worn at all times, but I don't know if any of those can run general-purpose Android without having a terrible battery life.

ccozan• 10 years ago

What is wrong with inertial navigation? Just need to mark a starting poing ( like, your house door ) and then just walk around and mark the places.

I've seen in the past some Android apps that do this, not sure now what's the situation.

EDIT: found some paper about it and how it worked: http://hkr.diva-portal.org/smash/get/diva2:475619/FULLTEXT02...

hansjorg• 10 years ago

The problem is integration drift. I don't think it's really feasible to do inertial navigation with a smartphone.

The paper you linked is also discussing use of WiFi and Bluetooth.

Edit: here's a good overview: http://stackoverflow.com/a/7835988

creshal2• 10 years ago

If I had to guess I'd say most phones (esp. cheap Androids) have too shitty sensors for this to work reliably enough.

woodcut• 10 years ago

There was a startup in Berlin called 42 Reports that was built around this idea but for tracking people in shops and malls, word is it bombed owing to the technology just not being accurate enough, i think now they've pivoted and scraped an exit.

PakG1• 10 years ago

Isn't this why beacons and iBeacon are supposed to be the next big thing in retail? I've got a friend who just got hired to do sales in Asia for a beacon company. Apparently, they're blowing up (or trying to)?

roel_v• 10 years ago

This would be a valuable addition to other methods of determining presence in building automation systems. What would it take/cost to build a tiny dedicated device that would wake up every, say, 5 seconds, analyze wifi signals (what's called the 'fingerprint' in this system if I understand correctly) and ping the server with that data? More concretely, would it be possible to build such a device for low prices (<50USD) with > say, a month, of battery life?

jakobegger2• 10 years ago

It would probably be best to use a microcontroller instead of a full cpu. I really like the Particle Photon. It costs $20 and is a joy to work with. It barely needs any power in sleep mode, and you can set it to wake up at scheduled intervals. Depending on the battery you use, a month of battery life shouldn't be an issue if it sleeps most of the time.

There are other microcontrollers with Wifi and similar capabilities that are even cheaper, like the ESP8266 at around $5, but I haven't worked with those before.

EDIT: I just saw you want it to wake up every five seconds --- in that case sleep won't help much and you'll need a big battery for a month of use, since wakeup and scanning for networks takes a few seconds. Waking up less often (eg. every 15min) would be more feasible, but it really depends on your intended use.

qrv3w13• 10 years ago

Home automation has always been my main goal. I've been working with some electronic devices as you mentioned. For those interested, Sparkfun has "The Thing": https://www.sparkfun.com/products/13231 which is a good way to get into the ESP8266. I've also tried using Raspberry Pis, which works pretty well but are still too big with the battery to go carry around a building. I'm hoping to try the Pi Zero in the future with a small LiPo battery.

lhaussknecht3• 10 years ago

They claim a typical accuracy of 10 square feet (< 1 square meter) which would be really really good. Even systems with beacons are not better.

creshal2• 10 years ago

Well, since this turns wifi APs into beacons, it's not surprising to see comparable results.

qrv3w13• 10 years ago

Don't take my word for it, you should try it out!

It really depends on how many routers are in your area. For places in cities, there are tons and tons of routers so its very easy to get pretty good resolution. For places more remote, you might not see many routers and then you would be for more limited in your resolution.

thenomad• 10 years ago

Assuming you wanted to very precisely map a small area (50mx50m or so) to the maximum resolution possible, and you had a budget sufficient to buy and place 20 or so wifi routers, what sort of resolution could you get?

I'm looking at this for gaming applications. Don't need milimeter accuracy but +- 30cm would be good.

asadlionpk• 10 years ago

Cool project. I have tried using both wifi and IMU motion sensors for mapping indoor and it's not really that impressive yet. This is still a very hard problem to solve. Google seems to be working on it: https://www.google.com/atap/project-tango/

There have also been many other projects like http://wearnotch.com/

For now, External distance cameras (Kinect-like) seems to be the most accurate and usable method. Something like what these quadcopters use: https://www.youtube.com/watch?v=AiCFtmdrvHM

qrv3w13• 10 years ago

Thanks for the links! I haven't seen those.

I know that this already exists in many variations: https://github.com/schollz/find/blob/master/FAQ.md#doesnt-th...

Still, I've never seen one that is open-source that works pretty well, so I thought I'd put mine out there.

greggman• 10 years ago

~10sq feet in resolution

Seems like that should be in the first 3 lines of the description, not near the end of the FAQ.

Very cool project.

onecooldev24• 10 years ago

Can some one explain me, why just not use bluetooth LE? I understand you need BLE beacons, but any other reason.

lhaussknecht3• 10 years ago

No, you don't need beacons here. It works using "fingerprints" (and machine learning) of nearby APs.

qrv3w13• 10 years ago

Right. Bluetooth beacons are a piece of hardware you would have to buy. Basically this tries to accomplish the same thing with just software. Here there is no hardware other than the server (which is provided) and a client computer (which you probably already own).

11thEarlOfMar• 10 years ago

Thinking about corporate applications...

Does it accommodate mobile APs on smart phones or personal hot spot devices? Seems those might confuse it in an enterprise setting.

Also, I would assume that the software will differentiate APs with the same SSID as in an enterprise situation and rely on MAC IDs. But just so I don't have to assume, can you confirm that it does?

qrv3w13• 10 years ago

can you confirm that it does?

Yes, it will differentiate APs with the same SSID as it relies on MAC IDs. I use it at my university with no problem (which is an enterprise situation).

Does it accommodate mobile APs on smart phones or personal hot spot devices?

It uses mobile hot spot information, however if the hot spots disappear it will not affect the results too badly, as long as there are some permanent AP fixtures. Anecdotally, I've used this system in airports (which house many personal hotspots) and it still has good recognition.

pavel_lishin• 10 years ago

Awesome. I tried creating something like this to help get around our very confusing corporate headquarters, but gave up. I will almost certainly use this now!

Show HN: FIND – an indoor positioning system for smartphones and laptops

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