Gadgeteer GPS Module failure

Archive
61

Good decision! The design is poor. The external interrupt feature is not implemented, and the time pulse, which is necessary for precision timing, is not connected.

62

I just got mine today. I checked the sticker on the module and it doesn’t appear to be the same run as the original ones with the issue.

What is a normal time to lock onto a satellite?

While sitting outside in my screened enclosure (with an otherwise clear sky), it took approx 480 seconds to get a single satellite.
The second time it took 450 seconds.

So I went outside the enclosure (braving the mosquitos of FL) and it took 167 seconds. 2nd test was about 42secs.
But I’m still only getting 1 sat. That can’t be right … can it?

My code (in part) to show sats:


if (nmeaSentence.Substring(0, 6) == "$GPGGA")
            {                
                string[] stats = nmeaSentence.Split(splitArray);
                if (stats[6] != lastSateliteCount)
                {
                    lastSateliteCount = stats[6];
                    display.SimpleGraphics.DisplayRectangle(Colors.Black, 0, Colors.Black, 10, 50, 150, 10);
                    display.SimpleGraphics.DisplayText("number of sats - " + stats[6].ToString(), smlFont, Colors.Cyan, 10, 50);
                }

I only have the DP, Spider, T35 and the GPS connected. Could it be a power issue? I’m using the USB from my lappy.

I would hate to think that I flushed my money down the toilet.

The GHI stuff I got works great. This so far has left me underwhelmed … but I could be doing something wrong.

@ ransomhall - any eta on your module?

63

140 seconds on a cold start is perfectly acceptable. Cold boots on some modules can take between 30 seconds and 20 minutes.

64

@ mhectorgato - I’m using with a SP red module only with US powered. We don’t have a DP here to rest on the wall outlet.
If you can test it I really appreciate. Maybe it can help GHI guys to diagnostic the problem.

Thanks!

65

@ Skewworks - But why in my tablet and cellular that uses same chip are so fast? Excuse me about this dumb question, I just don’t understand why the module is so slow(if it works…).

Thanks

66

That’s crazy – 20 minutes!

If I wanting to use this develop a commercial product, do I tell my customers … after turning on my device – take a nap, get a cup of coffee or read a chapter out of their favorite book – before it’s ready to use?

67

Will do. But according to Skewworks (who usually makes sense :slight_smile: ) it will take a while for it to get a satellite fix…

68

@ mhectorgato - Yeah, its completely insane has to wait for 20m for a FIX. I know that my cel and tablet uses AGPS from wifi, 3g, etc, to help the GPS get first fixes but, while they take nothing more than 2-5s to get my current position, my spider+GPS past today 4 hours on, outdoor during the day at clear sky(no clouds) and… nothing…

Just curious, any one in this forum is from Seeed team? If yes, is there any explanation for it?

69

Here’s the differences:

  1. Your cell phone can hit the cell towers to grab data that assists in fixes.
  2. Your tablet/cell have more power behind them
  3. Better antennas

There’s a huge difference between whats in cell/tablets and the $40 GPS modules you pick up for experimentation. More powerful options exist, but expect to pay more for them.

70

How about doing a WARM boot on the module? Keep a constant power to it, that helps GREATLY. The module from Adafruit supports this and even has a coin cell holder attached.

71

@ Skewworks - Yep, I know and agree with you.

I’m just asking cause I did go to nokia and Samsung tech centers, and both GPS chip for my tablet/cell are ublo as this module. Like I said, I know they have a little help(AGPS) to get a fix in seconds. But 4 hours and no fix? Something is very wrong right?

And, regarding the Antenna, anyone ordered another more powerfull antenna to test? Is there any other antenna that works with this module so I can buy it for test?

Regarding the power, I was thinking that the USB power is enough for those modules, if not, @ mhectorgato here told that will test with a DP power on it and let us know.

72

can you provide links to this other gadgeteer modules?

Thanks!

73

Community member shred a design with us on a gps module with battery for warm boot. Not sure of his plans yet.

Of course gps is very important and we are seriously looking into a better alternative. Note that any rs232 gps module will work easily with any gadgeteer main board.

74

Adafruits module isn’t gadgeteer (Adafruit Ultimate GPS Breakout - 66 channel w/10 Hz updates [PA1616S] : ID 746 : $29.95 : Adafruit Industries, Unique & fun DIY electronics and kits) but Architect is working on one based on that module.

4hrs is unacceptable for a fix, but I believe there is not only an issue w/ the Seeed module but there is a related power issue on the Hydra. I haven’t personally tested this, so don’t take my word on it.

You could easily connected it w/ GHI’s $4 extender module: http://www.ghielectronics.com/catalog/product/273

75

@ Gus - Humm minteresting… Maybe this design can be used to you guys provide your own GPS module better than this Seeed one? Nice.

Also, I tried 2 GPS sticks that is a USB-to-Serial port and on PC is on COM8, but it is not detected when I’m using the USBHost class… Is there any sample Gus about using a Serial GPS on Gadgeteer here?

Thanks again!

76

Nice. Lets hope Architect releases it soon! :slight_smile:

But just to let you know, as I said, all this test was with both Hydra and Spider. Since people told that Hydra is with problem, I’m waiting for the problem be detected by GHI and for a recall and I’m only testing from today on, with the Spider that Gus/Joe told that is working, for me still same problem.

THanks

77

Correction: Ransom is working on the module.

78

That would be ransomhall.

79

Try to use USB host class directly, no gadgeteer and see what device it detects.

80

Beat you to the correction :stuck_out_tongue: