gps

[Newguy2]

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?

[WhateverFits]

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.

[purps]

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.

[Marie.O]

purpse,

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

[purps]

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.

[WhateverFits]

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. 

[bongowongo]

Well my bongo is 15 meters, so for me 15 meters is localised enough.

[Schmich]

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.

[purps]

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.

[Techstyle]

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

[corrosion]

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)

[purps]

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.

[Marie.O]

Unfortunately, Bluetooth range is too good for most apartments/houses

[purps]

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.

[JoakimL]

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?