altitude in gpsapp

In the satellite view of gpsapp, is the number right above the speed the altitude? This number never changes and is always dim. I thought that if you had 4 or more signals, then gps could give your altitude as well as coordinates. Do not all gps recievers give altitude or is there an option I have to set for this or what? And also what do all the other numbers on this screen stand for? From top to bottom... coordinates, then I think the altitude, then speed, then something that has a number then says HD, then something that says 2D, then i think the number of sattelite signals and SV. What do all these things mean?

I seem to recall that GPSapp has no trouble displaying the altitude from my receiver.

I think that not all GPS units will give the altitude, and that's probably what you're running into. I don't remember where on the screen the altitude is, though, so I can't help you decode that screen.

For GPSAPP the display area between the satellite signal strength bar graphs and the polar plot of satellite elevations and azimuths has the following information:

The first line shows the altitude in feet or meters and is dim when the position data is derived from a 2 dimensional solution (2D) and bright when the receiver provides a 3 dimensional solution (3D). Your receiver will typically use 3 satellites and the last known altitude or a user entered altitude if it is set to 2D or has only 3 satellite signals available.

The second line shows your GPS measured velocity if it is available from the GPS receiver.

The third line shows the HDOP (Horizontal Dilution Of Precision) as provided by the receiver. This is a guide to the degradation in horizontal position accuracy that can be attributed to the geometric relationship of the satellites (being used for the solution) to the user's receiver.

The fourth line shows whether the GPS receiver is operating in 2D mode or a 3D mode. and also the number of satellites being used to compute the solution. This number can be more than 4 if the receiver is able to compute an "overdetermind" solution.

Lynn

Thanks, that is just what I was asking for. So even when I have 7 satellites being used at one time, and it is still in 2D, does this mean my reciever doesn't send the altitude. Or is there an option I have to set to make gps app do 3D.

I doubt it has to do with GPSAPP. It sounds to me like your receiver has been set to 2D altitude hold mode by some other application. What kind ot receiver is it? It could be that GPSAPP is not sending your receiver the initialization string that would forced it to return to 3D if it has somehow been set to 2D.

Lynn

It is a radioshack digitraveler. There are no options on it or anything. Not even a display. it is pretty much just a plastic disk/ball with a serial cord attached to it.

Google led me to this:

http://www.zauruszone.com/wiki/index.php?SerialPort

Which says this:

Using the Radio Shack $99 DigiTraveler? (PC edition)

Note: much of the weirdness discovered during this adventure has been documented above.

Walking into the Rat Shack one day I discovered the Radio Shack's DigiTraveler?, a $99 GPS receiver with no display that hooks up to your laptop. It came with DeLorme? software, which made it a better deal than when DeLorme? offered a similar packet with their EarthMate? or TripMate? receivers. Better yet, the Rat Shack model outputs NMEA using a serial cable, instead of Rockwell Binary, so it will work with more apps! I had been looking for a battery box to bolt onto a ETAK Rockwell Binary receiver I had for a number of years, and not relishing having to build a Rockwell Binary decoder (kind of dead-end) I jumped on the Rat Shack model.

The DigiTraveler? runs on 3 AAA batteries for, it claims, 12 hours. When hooked to a PC it uses the PC's TxD line (from PC) to detect whether or not it is connected to the PC, and turns itself on.


lots of Zaurus related stuff in here!.


As far as this receiver is concerned, I cannot say how good it is. I just gotten it working. It attempted its first fix with the assumption that it was located somewhere in Asia, which probably slowed down this first fix. However, after leaving it "off" for about half an hour, and plugging it back in, it seemed to remember where it was, and also seems to store an almanac. I would bet this is forgotten when the batteries are pulled. I'll either post more later, or let someone else add to this.


Which implies a DeLorme/Rockwell core receiver. I am not familiar with the command structure for these but perhaps someone else who is, can point you to the init strings.

Lynn

but perhaps someone else who is, can point you to the init strings.

Anyone?

Not really sure, but according to what I have found here, it should be possible to clear a fixed altitude setting by adding the following fragment to nmea_init (gps_nmea.c, line 432) after the other zodiac init strings.

memset(buf, 0, sizeof(buf));
dat = (unsigned short *)buf;
dat[0] = 3; /* serial number, should increment XXX */
zodiac_send(1219, dat, 6); /* 11 - 5 */

Ok, so what does that mean in english?

Add that code fragment and rebuild gpsapp.

FWIW my Garmin StreetPilot ColorMap (not a StreetPilot III, sadly) will output a valid altitude, but never reports a 3D fix, so GPSapp keeps the altitude dimmed.

I admit it's a bit odd to see "2D 8SV"

That's another thing...it's a 12-channel receiver, and will claim 9 or 10SVs on it's own display, but still only reports 8 through NMEA.

No matter, if I ever get time to work on the TINI gps board, I'll stop needing the StreetPilot in the car. (Who'd have thought I'd have *less* time since I got laid off. )

Who'd have thought I'd have *less* time since I got laid off.

You were laid off?

Yeah, let go on the 22nd. Lots of irons in the fire at this point, which is why I don't have any time. At some point, I'll need to take some time and enjoy the severance package but that hasn't happened yet. -Z

Well, best of luck to you with whatever irons you've got in the fire.

I've been dealing with some distasteful political stuff at my job and I'm feeling disillusioned at the moment. Perhaps we should do a start-up?

Perhaps we should do a start-up?

I thought about mentioning that when I was unemployed a few months back. With all the killer talent in a variety of different fields we have here (myself probably not included ) we could make one kick-ass gaming company; just as an example. We'd kick-ass doing anything, really.

This is the best guide to doing a start-up I've ever seen: The Beermat Entrepreneur

I'm an angel investor in a bunch of start-ups, and if I can contribute, I'm more than interested in whatever you come up with

Perhaps we should do a start-up?

I'm in for that. I haven't done anything useful in the last four months here (unless you count the random shuffle simulator I did for the bbs). I keep thinking how great it would be to have a job developing software (which is what my job description implies).

Very interesting. I've been wanting to start a local, permanent, lanparty place here. Basically a place for people to come to hangout and play games, and have organized events, etc. Of course, the actual plan was a lot more complicated. It had all kinds of great ideas in it. However, like many other things, it just never went anywhere.

I really wanted to do a LANParty place too at one time, and even drafted a proposal for my former finance professor (who has funded many startups). Then I found out someone had already done it in our area, so I gave the idea up. Not sure how well the place worked out, though.

I keep thinking how great it would be to have a job developing software (which is what my job description implies).

Yeah, when I said "gaming company" up there I meant developing games. Seems like everyone else is doing it, so why not. Probably not the best place to start considering all the competition, but it sure would be fun.

Yeah, without having actually done it (I've heard it can be a LOT of work) I think developing games would be awesome. The idea of creating interactive worlds for other people is just so appealing. As for the competition, come one . . . we're empeggers!

I've been wanting to start a local, permanent, lanparty place here.

That's the only kind of startup that I'll actively avoid. I personally know someone who tried it and it didn't work out for him.

Now if you've got a business model where a lan-party "section" is part of a larger business, such as a nightclub, a computer store, a conventional arcade, or a pizza parlor, then maybe we can talk. But as far as I know, no one makes money on just LAN parties.

Yeah. Like I said, it was a lot more complicated. It had an arcade, a console gaming section, a pizza parlor and a separate "business" section for people to come in and "rent-a-cube" (kind of like Kinko's) for a flat rate per hour where they could use the internet, send/receive faxes, etc. It was basically turning into a Dave & Busters on crack. Lots of kewl ideas, but the whole thing never went anywhere, like I said. Around here I think something like that would really take off.