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Show HN: Indoor Location you can try yourself (play.google.com)
52 points by navpatel 1981 days ago | hide | past | web | favorite | 46 comments

Constructive criticism: After reading the description, I don't understand what this application does. I am not initmately familiar with indoor mapping/positioning or WiFiSLAM. The term "indoor mapping showcase" is vague to me.

I think it lets me build maps of indoor locations? Somehow? Based on the screenshots, maybe by walking around my room? It seems like it could be neat, but I don't want to go through the trouble of downloading an app if I don't know what it does.

Fair enough. We have a 90 second video on YouTube that should give you a sense of what you'll get: www.youtube.com/watch?v=B_GdXp_Swjs

But basically, yes. It lets you build indoor positioning by walking around my room.

Not everyone has time to watch videos, especially at work. A simple text description would work a lot better.

you're right. we're working on a blog post describing the app, and should probably get a better description on google play

You can add that video to your App description on Google Play also...

We built this because we felt Indoor Location technology is too inaccessible. There's lots of buzz about indoor location, and many canned demos, but very few people seem to put it out there.

We've built some cool tech, and we want people to try it out first hand.

I'd love to know a little more about what's going on here. Does it use accelerometers or just wifi signals? One key question: could I share these floorplans? That is to say, using the sensors on HTC Android device #1, could I sent a floorplan to my friend Samsung device #2 and have them be able to similarly track their location?

Does it only work indoors, or is that just for demonstration?

The floorplans are definitely transferable! Once you’ve mapped a location once, it works automatically on all devices.

In fact, if you walk into a location that someone else has already mapped, the “Where Am I” will automatically load that map up on your device and start showing your position.

If you’d like to do more advanced stuff with your floorplans, make a WiFiSLAM SDK account here (access.wifislam.com) and we can get you started.

What's in the SDK? I looked around and there was not even a mention of ios versus android. Is it a set of armv7 ndk android libraries? Or something else? Can I use it on simulators running on OS X?

The current WiFiSLAM SDK is an Android java library, available as an Eclipse project with sample code snippets that allow you to add your location to any existing Android app.

We have an iOS SDK that works, unfortunately since Apple disabled WiFi scanning in iOS 5 we can no longer publish it. It still works on jailbroken devices, but not a big target audience. We have a workaround in the works that will incorporate iOS devices

It will work wherever there are ambient WiFi signals, indoors or outdoors. This is particularly interesting indoors because it’s possible to get GPS outdoors, while you can’t indoors. We have tried mapping around Mountain View and it’s worked great

My specific use case is in tracking very small movements, i.e. ones that a GPS would not pick up. I was wondering if this would provide a solution to that, but it still seems to have a delay attached.

Doesn't take away from some very impressive tech on display. Kudos.

thanks! How small are the movements you’re trying to track? And what kind of time delays are you trying to get under? You can try mapping the same location multiple times (the more mapping the more accurate our system will be)

@untog: It's actually a sensor fusion approach that combines both accelerometers and Wi-Fi signals.

Can you guys give any insight into how you're combining the sensor data? I'm a newb on the topic, but I was trying to do something similar in a different domain and got stuck trying to make a kalman filter. I tried to get an EE friend to explain them to me, but I couldn't get it.

Multiple fields actually invented Kalman filters independently and it turns out they are all actually the same thing, they just have widely varying derivations. My personal favourite explanation comes from the textbook: Probabilistic Robotics (2005) by Thrun, Burgard, and Fox.

The explanation on the Play Store didn't make sense to me, only by watching the video could I understand what it did.

Actually, a coworker thought it worked the other way round :) (build a map by walking around).

I don't have a floor plan of anywhere, they're not required here in Uruguay.

Btw, video: http://www.youtube.com/watch?v=B_GdXp_Swjs

A lot of people just scribble down a drawing on paper, and then use the "I Want To Take A Picture With My Camera" option. The floorplan is just a reference point, so you can makeup whatever floorplan makes sense for you. For example: https://lh4.ggpht.com/Y1z9Qt5EggwNdg0Caua9dJGWV8dZmnYhioten1...

Thanks :) , I can do that :) .

Will try it out at home. Looks cool, and sounds like it could lead to interesting use cases.

If you don’t have time to try the app, watch this video instead. It’s 90 seconds. www.youtube.com/watch?v=B_GdXp_Swjs

Oh also, if you're up for learning more about the technology/platform in general, take a look at blog.wifislam.com

Sounds really great! I appreciate you put an App out there so we can try it out ourself and not just read a paper or watch a video. I tried it, but unfortunately my old HTC Wildfire is so slow that it becomes unusable. I was able to take a picture but I can't even place the cursor on the map. Of course I don't expect you to support such an old and crappy phone. I will try to get hold of a faster Android phone.

I also downloaded the SDK. Is it possible to use it on a Laptop, too? Maybe, by emulating Android? I have no clue but I would have a few ideas on how to use it with a Laptop.

As Gee has pointed out, there is also http://www.indooratlas.com/ which uses the magnetic field for indoor SLAM. Do you have any info on how your system compares to theirs?

Anyway, thanks for sharing this!

IndoorAtlas is similar, but doesn't require WiFi in the building. It utilizes magnetic variations to detect the location. http://www.indooratlas.com/

    Error reading floorplan

    There was an error reading your floorplan from storage
Nexus 1, trying Windows7 Paint generated .png and .jpg

Does it work if you try again? Looks like this is an issue with mod_python, which cannot accept chunked encoding (https://issues.apache.org/jira/browse/MODPYTHON-222)

We’re not sure under what conditions the client decides to send chunked vs not, but in our testing if you retry it should get through.

strange! we're looking into it.

meanwhile try scribbling it down on paper and taking a picture of it :)

I just want to point out that I first mis-parsed the name of the technology as "wif islam".

Heh. Not the first time it's happened :P

Aisle 411 is doing indoor location: http://aisle411.com/

Yeah, Aisle411 is definitely doing some cool stuff with indoor location, and are the types of partners that make a lot of sense for us. Indoor location is made up of two key components: Real-time positioning (e.g. WiFiSLAM) and point-of-interest databases (e.g. Aisle411)

What happens if the WiFi base station has dynamic power levels - or are most bases left with fixed power?

In our experience, we've found that most access points do in fact have a fixed power. Either way, the system can accomodate some amount of dynamic changes.

doesn't work for my on campus wifi. any requirements on the wifi network? My phone is htc one x.

No specific requirements for wifi at all. Which part didn't work exactly?

when I was walking the cursor does not move along. I think my campus wifis are using signal repeaters.

it should still work with signal repeaters. Did you map the location first? If this is a new location (i.e. someone else hasn't mapped it yet), then what you want to do is select the floorplan in "Browse Floorplans". You should see a button to start mapping, hit it & follow the on-screen instructions (basically walk around and hit the "mark point" button or the volume up/down button after positioning yourself on the map). once you are done, hit stop mapping & hit yes to upload it to our servers for processing. after some time (maybe 2-5 minutes depending on load) you should be able to hit "Where Am I?" on the home screen to have it track your position.

Let us know if it's still not working for you.

Did you write image recognition from scratch yourselves, or is it based on a lib?

It's actually based on the ambient Wi-Fi signature of the airwaves around you. There is no image recognition involved!

Ah ok, so the *floorplan you supply just acts as a "background/walking-guide" for your mapping?

yup, that's right

Ok, thanks. Was looking for a img rec lib for floorplan drawings when I fell upon your post - hence the question.

Crashes on startup. HTC Evo V 4G, Android 4.0.3. Reported via Google Play.

Thanks for the report and sorry about the crash!

Any chance your sdcard/external storage is mounted or otherwise unavailable? We're supposed to have a popup to prompt you for that, but it looks like some code slipped in before the prompt :(.

Sorry, missed this for a couple of days. Hmm, I may have been charging via USB to the computer at the time. Will try again later.

Does this adapt it's map on the fly like a true SLAM, or does it only work off the access points detected during the configuration phase?

We’ve found good results using only the configuration phase; we have versions with full SLAM but it tends to work well without it. The QuickMap app uses only access points detected during the configuration phase.

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