LinuxMCE Forums

General => Users => Topic started by: Newguy2 on October 03, 2011, 06:34:37 pm

Title: gps
Post by: Newguy2 on October 03, 2011, 06:34:37 pm
Gentlemen, being that I am clueless in regards to this, I have a question for your brilliant minds. What is the feasibility of using GPS for proximity detection. Taking into consideration the conflicts that arise from using multiple Bluetooth dongles in close proximity, would GPS be more usable in terms of location accuracy? Perhaps entering a predetermined GPS area can trigger commands from a cell phone Orbiter to lmce? I was wondering this for a while, but I never was going to ask until I came upon several android apps such as tasked and automatit that does this, but i don't know if it would be possible or useful for lmce?
Title: Re: gps
Post by: WhateverFits on October 03, 2011, 06:51:35 pm
GPS accuracy on your average handheld device is around 15 meters so if your house is absolutely huge, then I guess this might work. Also GPS is nearly useless indoors due to antenna interference from the building.
Title: Re: gps
Post by: purps on October 03, 2011, 07:37:00 pm
It's not as much as 15 metres, more like 1.5 metres, but yeah it wouldn't work well in the house.

RF tags would be the best thing I reckon!

Cheers,
Matt.
Title: Re: gps
Post by: posde on October 03, 2011, 07:40:50 pm
purpse,

where do you get 1,5m accuracy with GPS using civil equipment? I rarely get the 15m
Title: Re: gps
Post by: purps on October 03, 2011, 08:01:53 pm
Well maybe not 1.5, but certainly better than 15. Basic devices will be around 10 m, but I'm sure my phone can do better than that.
Title: Re: gps
Post by: WhateverFits on October 04, 2011, 05:54:00 pm
http://www8.garmin.com/aboutGPS/

Scroll down a third of the way down the page. Specialized technology can get it down to three meters but fifteen is the norm.

Have you ever actually verified the accuracy of your GPS using known coordinates? I haven't but now I'm curious. Mapping software gives hints as to where you are so the GPS device itself appears more accurate than it is. I'm going to find some GPS coordinates of an exact spot near me and test out my GPS ASAP.  ;D
Title: Re: gps
Post by: bongowongo on October 04, 2011, 08:07:01 pm
Well my bongo is 15 meters, so for me 15 meters is localised enough.
Title: Re: gps
Post by: Schmich on October 05, 2011, 07:28:58 pm
When using my smartphone for biking or cycling recording it's pretty damn accurate. At worst I'd say it's about 5meters inaccurate, most times it's right on spot to ±2 meters. I'm not sure how much the software helps but I don't exactly follow roads when I run for example.
Title: Re: gps
Post by: purps on October 05, 2011, 10:45:51 pm
Yeah you are quite right, I use my phone for running as well, and it knows which side of the road I am on at any given time. I always thought it was accurate when driving as well, but as you say, this software can sometimes "snap" to known roads.
Title: Re: gps
Post by: Techstyle on October 06, 2011, 09:47:28 pm
is it absolute or relative accuracy that you are interested in? anyway relative is much better, agricultural vehicles use this for slip control by checking ground speed vs wheel speed
Title: Re: gps
Post by: corrosion on October 08, 2011, 09:49:03 pm
Hmmm... Bluetooth might be a good one, have a bluetooth dongle in each room that syncs to your phone.. bluetooth has a very short range.

Another idea if your the only one in the home you could use a laser tripwire at the entrance of each room (ir light rather than a laser)
Title: Re: gps
Post by: purps on October 09, 2011, 01:08:27 pm
Hmmm... Bluetooth might be a good one, have a bluetooth dongle in each room that syncs to your phone.. bluetooth has a very short range.

Another idea if your the only one in the home you could use a laser tripwire at the entrance of each room (ir light rather than a laser)

This is how it has always been done.
Title: Re: gps
Post by: posde on October 09, 2011, 01:52:00 pm
Unfortunately, Bluetooth range is too good for most apartments/houses
Title: Re: gps
Post by: purps on October 09, 2011, 02:00:04 pm
I wonder if there is a way to "fine tune" the range by shielding the dongle in some way?

RF engineering is a bit of a black art unfortunately, but I will ask the boffins at work if there is a way of modifying/shortening the internal antenna. Might be worth experimenting with foil to begin with though.

Cheers,
Matt.
Title: Re: gps
Post by: JoakimL on October 09, 2011, 06:50:57 pm
There ought to be a way to restrict the amplification power of the bluetooth dongle, I know I've seen it in some software. Problem is that it might be buried in the hardware driver. Anybody who knows?
Title: Re: gps
Post by: uplink on October 11, 2011, 03:07:07 am
purpse,

where do you get 1,5m accuracy with GPS using civil equipment? I rarely get the 15m

My HTC Wildfire seems to hit me right on the head each time... while outside... in an open parking lot. Well... it hit me right on the head in London, ducked behind tall buildings too. And while moving at 100 km/h by train. I must have the military version :)
Title: Re: gps
Post by: uplink on October 11, 2011, 03:12:27 am
Anyway, I guess a starting point would be Wikipedia: http://en.wikipedia.org/wiki/Indoor_positioning_system and there's a lot to read there.
Title: Re: gps
Post by: posde on October 11, 2011, 10:07:54 am
Turn of GPS-A and your head will be save.
Title: Re: gps
Post by: davegravy on October 11, 2011, 04:17:11 pm
I wonder if there is a way to "fine tune" the range by shielding the dongle in some way?

Most definitely. It's called a Faraday cage, and you could construct one around each room to contain its local bluetooth signal.

Oh wait, you wanted a *practical* solution...  ;)
Title: Re: gps
Post by: uplink on October 12, 2011, 03:17:04 am
From a theoretical point of view, at one point I wanted to know about a GPS-like solution where you put your own "satellites" around your house, say... one in each corner of each room... 4 per room if your rooms are shaped like a regular upright parallelepiped. I haven't quite found an answer, but somehow I know an amateur radio-electro-geek could build a HPS (Home Positioning System) with stuff from Radio Shack. :) It can double up as a GPS jamming device if you use the same frequencies, and enough power and error correction to overcome the HPS jamming signal coming down from orbit.
Title: Re: gps
Post by: Techstyle on October 12, 2011, 05:58:20 am
seeing as we are looking at options that are 'outside the box' you could set yourself on fire and use a 1-wire temperature sensor to detect you presence.
Title: Re: gps
Post by: uplink on October 12, 2011, 06:10:03 am
seeing as we are looking at options that are 'outside the box' you could set yourself on fire and use a 1-wire temperature sensor to detect you presence.

We need a Slashdot style "Funny" button :D
Title: Re: gps
Post by: purps on October 12, 2011, 10:45:06 am
seeing as we are looking at options that are 'outside the box' you could set yourself on fire and use a 1-wire temperature sensor to detect you presence.

Lawl. Motion sensors combined with the continuous waving of your arms might be less painful. At least in the short-term.
Title: Re: gps
Post by: posde on October 12, 2011, 05:45:34 pm
It is quite obvious, that all you need is a kinect in every room, which has learned all occupants of the house, and LinuxMCE is using it for follow me.
Title: Re: gps
Post by: locutus on October 12, 2011, 06:09:11 pm
could you use wifi antennas at each corner of house and triangulate your phones position?
Title: Re: gps
Post by: bongowongo on October 13, 2011, 10:04:52 am
It is quite obvious, that all you need is a kinect in every room, which has learned all occupants of the house, and LinuxMCE is using it for follow me.

How feasible is this?
Title: Re: gps
Post by: purps on October 13, 2011, 10:25:54 am
http://nitrogen.posterous.com/home-automation-and-lighting-control-with-kin
Title: Re: gps
Post by: uplink on November 14, 2011, 11:34:36 am
If your house is full of iPods, iPhones, and so forth, here's something interesting from Slashdot today: http://apple.slashdot.org/story/11/11/13/1841204/ios-app-acoustically-measures-distances-up-to-25-meters

As is customary with Slashdot, I haven't read the article, so it may not even be on topic :P