dualsportmaps.com - Android App

[Wind-venture]

Originally Posted by craftycoder

The GPS feature does not transmit. It only listens and amplifies.

I think you mean analyze instead of amplifies. Unless you're thinking about how the receiver amplifies the signal from the antenna and pushes it into the processor?

The phone radio does not need to have anything to do with the GPS. Some software that you have used may use both, but it is not a requirement.

Most of the navigation software that I've seen on cell phones uses both. One program used the cell signal to update the location maps after the phone gave it the GPS signal. That wasn't nearly as fun because once out of the cell area you're left with a useless application.

In this application it would make no sense because this app is really for use when you are in the wild. If you are on a freeway, where the radio would help, I suggest you use Google Navigation as I assume their billions of dollars can do better than I can offer in my spare time.

Yeah, it's been a bonus for me on the roads.

If I can't make this work with real time GPS data lets assume that the project dies before anyone but myself sees it in action.

I appreciate your efforts. I'm following your website. Thanks

[craftycoder]

Originally Posted by Wind-venture

I think you mean analyze instead of amplifies. Unless you're thinking about how the receiver amplifies the signal from the antenna and pushes it into the processor?

I meant amplify because I figured that was the only place where the circuit would be consuming meaningful amounts of power. I think you are correct though, it also likely consumes a non trivial amount of power analyzing the signal as well. Still, much less than the radio. If the radio is removed from location awareness process I don't expect power consumption to be an issue.

Most of y'all have a set of experiences in your mind about how these devices work. Your experience tells you that a map application uses the cell radio and GPS to determine location. Just trust me when I tell you it doesn't need to. It is trivial to query the hardware for location updates from any 1 of 3 sources on the phone. Network, GPS, and WIFI all offer clues. I will only be requesting info from GPS because that is the only likely candidate on the trail and it should keep power consumption down.

This is why those Apps generally consumer a lot of power. A lot is going on here that won't help us out on the trail.

subscribed! good luck on getting this project on it's feet.

[Wind-venture]

Sounds like you're right on track craftycoder. Although your terminology is off a bit. For instance while your differential between the cell and the GPS is right on, the GPS is still using radio tech.

Global Positioning System

GPS frequency overview

Band	Frequency	Description
L1	1575.42 MHz	Coarse-acquisition (C/A) and encrypted precision P(Y) codes, plus the L1 civilian (L1C) and military (M) codes on future Block III satellites.
L2	1227.60 MHz	P(Y) code, plus the L2C and military codes on the Block IIR-M and newer satellites.
L3	1381.05 MHz	Used for nuclear detonation (NUDET) detection.
L4	1379.913 MHz	Being studied for additional ionospheric correction.[citation needed]
L5	1176.45 MHz	Proposed for use as a civilian safety-of-life (SoL) signal.

Check this how it works link out. Pretty decent explanation.
GPS Calculations



As opposed to the radio frequencies of cell phones. Below are the ones used in the U.S.


Frequency bands used in the United States

Current / Planned Technologies	Band	Frequency (MHz)
SMR iDEN	800	806-824 and 851-869
AMPS, GSM, IS-95 (CDMA), IS-136 (D-AMPS), 3G	Cellular	824-849 and 869-894
GSM, IS-95 (CDMA), IS-136 (D-AMPS), 3G	PCS	1850–1910 and 1930–1990
3G, 4G, MediaFlo, DVB-H	700 MHz	698-806
Unknown	1.4 GHz	1392–1395 and 1432–1435
3G, 4G	AWS	1710–1755 and 2110–2155
4G	BRS/EBS	2496–2690

[dpifko]

Originally Posted by craftycoder

...I will only be requesting info from GPS...

Hi Crafty,

This is good stuff. Keep on going!

When you request info from GPS only, how do you know it isn't using (or attempting to use) the cell phone or wifi signals to reduce the time the real GPS needs to home in? Is it a specific function call or call parameter?

Daniel

[craftycoder]

Originally Posted by dpifko

Hi Crafty,

This is good stuff. Keep on going!

When you request info from GPS only, how do you know it isn't using (or attempting to use) the cell phone or wifi signals to reduce the time the real GPS needs to home in? Is it a specific function call or call parameter?

Daniel

With most things computery, its all very specific. There isn't a "where am I method", there is a LocationChange listener and you tell it you use the network or the GPS.

I am just about finished getting the Vector OSM maps to render properly in perspective mode with the compass off 0 degrees. This is a big step in the right direction. I tested the map tiles in perspective mode following my driving (changing direction automatically such that the top of the map was my direction of travel) this afternoon and all looked nominal.

[Wind-venture]

Wheww


if it weren't for programming guys like you I'd still be navigating by the stars!

[craftycoder]

Originally Posted by Wind-venture

Wheww
if it weren't for programming guys like you I'd still be navigating by the stars!

Personally, I think the cartographers deserve most of the credit. I just love maps though. They make me feel like a kid, imagining getting into adventures in the foreign lands I'm looking at on the paper.

[dpifko]

Originally Posted by Wind-venture

Wheww


if it weren't for programming guys like you I'd still be navigating by the stars!

Here in SF there's so much fog we needed to invent an alternative.

[Wind-venture]

Originally Posted by craftycoder

Personally, I think the cartographers deserve most of the credit. I just love maps though. They make me feel like a kid, imagining getting into adventures in the foreign lands I'm looking at on the paper.

Right with ya partner!



The hours and hours spent pouring over all kinds of maps when I was a kid gave me an appreciation for the work put into it.

Imagine the effort back in first days. Now with all of the advancements and building off the work of the old timers I suppose it's easy for some to just take it for granted.

Whenever I meet someone like that i suggest a week retreat into the wilderness... well what we have left... without any sort of modern convenience... well except for the soft tissues.. that would be just too much to ask of the ladies...

Here in SF there's so much fog we needed to invent an alternative.

That is one of the few places I've not been in the lower 48

[craftycoder]

I did my first 2 wheel test of the software today. I did a 60 mile ride on a bicycle. Vector maps, in perspective mode, network radios shut off (airplane mode). Quite a bit of the course was under dense canopy. Pretty bumpy in places as well. I learned that it is important to fix the application in Portrait or Landscape mode because the bouncing confuses the accelerometer, the software had that feature already so that was a road side fix. The phones GPS tracked well in all locations. Speed seemed pretty accurate, but I don't have a calibrated speedo to verify, not that it really matters. Endurance wise, the app used 80% of my battery in 3 hours (it was not plugged in at all). There was also one area where the maps I rendered were not very good at all. I need to verify, but I believe the problem is in the source map file rather than the renderer, though that is just wishful thinking. All in all, a great first cycle test.

[beechum1]

Tracking this. Was the remote (PS controller) going to control pan/zoom etc functions, maybe some phone function as well???

[craftycoder]

Originally Posted by beechum1

Tracking this. Was the remote (PS controller) going to control pan/zoom etc functions, maybe some phone function as well???

Pan, zoom, add a waypoint. It will also probably talk to the music player.

I want to clarify that the remote is still just an idea. I have all the skills to implement it, except for producing an inexpensive weatherproof housing for it. I'm pretty sure I can find someone to do that portion so I may do it. The phone GPS was pretty good, so I don't exactly see the need to add an auxiliary GPS receiver at the moment. More testing will need to be done. The most compelling reason to create the remote though is so we can weatherproof our phones and still have access to map functions. That seems pretty important to me.

[beechum1]

Originally Posted by craftycoder

Pan, zoom, add a waypoint. It will also probably talk to the music player.

I want to clarify that the remote is still just an idea. I have all the skills to implement it, except for producing an inexpensive weatherproof housing for it. I'm pretty sure I can find someone to do that portion so I may do it. The phone GPS was pretty good, so I don't exactly see the need to add an auxiliary GPS receiver at the moment. More testing will need to be done. The most compelling reason to create the remote though is so we can weatherproof our phones and still have access to map functions. That seems pretty important to me.

agreed and agreed. What about this, and I realize the amount of work that goes into this EVEN IF you decide to do it, so i'm just spitballing..... programming some hotbuttons for say, texting, and voice command. i ahve the evo, and a bluetooth dongle for music that I would mount IN myhelmet if i felt so compelled to.

To be able to answer phone calls without stopping, touching the screen etc,to be able to reply to text messages without typing, and of course music player functions.... I like where you're going with that. if you want any help I'm in for what it's worth. If you remember, we talked about the gas station map idea a while back...

[wlightn]

Looks like this will be a great app. Looking forward to it.