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Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 8:49 pm
by jevermeister
Hi,

I am using an OSD now and noticed that the GPS data freezes and and the whole GPS is unusable.

I wonder, what happens if the number of sats drop below 5.

Is the GPS not updating anymore?

Nils

It took my GPS very long to get a fix, is it because of the dense weather or the low temp? It was faster the last time I tried it...

Thjanks in advance

Nils

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 9:14 pm
by EOSBandi
jevermeister wrote:Hi,

I am using an OSD now and noticed that the GPS data freezes and and the whole GPS is unusable.

I wonder, what happens if the number of sats drop below 5.

Is the GPS not updating anymore?

Nils

It took my GPS very long to get a fix, is it because of the dense weather or the low temp? It was faster the last time I tried it...

Thjanks in advance

Nils


Below 5 stats GPS navigation will stop, since it won't be accurate enought to use it for navigation.... I'm planning a mod (recommended by crashlander) which still enables RTH with 4 sats, but inhibits poshold...
Dense cloud cover indeed interfere with GPS... :(

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 9:38 pm
by jevermeister
Hi,
thank you for answering Andras.
But will the coordinates be updated if I fell below 5 sats?
Nils

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 9:54 pm
by copterrichie
I have a question also, if RTH or Position holding is not desired, is it possible to have a pass-through mode? In other words, just read the GPS and make the information available in the MSP Protocol?

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 10:05 pm
by jevermeister
that was my question. will the data in msp still be updated if below 5 sats?

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 10:27 pm
by EOSBandi
With serial GPS you will got constant updates, with I2C GPS not. (this will change with the next release of I2C-gps-nav

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 10:44 pm
by carlonb
EOSBandi wrote:With serial GPS you will got constant updates, with I2C GPS not. (this will change with the next release of I2C-gps-nav

Hi Eos,
As you are thinking about a new release of your I2C_GPS_NAV, please can take a look about a strange issue that some friends of mine has with their OSD ?
They told me that using a Mobidrone OSD or Rushduino OSD with I2C GPS the Home Arrow (Direction to home) is exactly reverted of 180 degree.
They use the same OSD as me, but I'm using serial GPS and all it's ok.
One more think, I modified this line of your code in I2C_GPS_NAV.ino in order to have cm/sec:

Code: Select all

 
//************* GPGSA FRAME parsing
          case GPRMC_FRAME:
          switch(param)
          {
           //case 7: i2c_dataset.ground_speed = (atof(string)*0.5144444)*10;      //convert to m/s*100
           case 7: i2c_dataset.ground_speed = (atof(string)/0.5144444)*1000*100/3600;      //convert to cm/s my mod
           break;

What do you think ?
Thanks in advance.

Re: Questions regarding 2.1 GPS

Posted: Wed Dec 26, 2012 10:44 pm
by jevermeister
Hmm. I use serial GPS.I believe my data freezes ehen below 5 sats...

Nils

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 12:25 am
by EOSBandi
jevermeister wrote:Hmm. I use serial GPS.I believe my data freezes ehen below 5 sats...

Nils

I cannot see anything in the code which prevents the updating of gps coordinates with a serual gps as long as you have gps fix.... even with 4 sats

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 3:15 am
by copterrichie
I think the problem is related to the Mega Serial ports usage at the same time. Trying to track down the bug now. When I have GPS, GUI and the ODS all running simultaneously, the GPS seems to lock up and the GUI is slow to start.

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 8:33 am
by jevermeister
yeah richard.that seems to bw the right explanation. Sometimes it seems to wotk again... I think I will update to i2c gps. i2c osd would be nice too...

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 1:33 pm
by copterrichie
jevermeister wrote:yeah richard.that seems to bw the right explanation. Sometimes it seems to wotk again... I think I will update to i2c gps. i2c osd would be nice too...


I think the best solution is to find out what is wrong with the Serials. I had it working perfectly with the pre-2.1, I will need to back track and see where things changed.

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 7:25 pm
by jevermeister
okay I will have a look at it too. wonder why the osd works perfect...

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 7:28 pm
by copterrichie
jevermeister wrote:okay I will have a look at it too. wonder why the osd works perfect...


No, I am not stating the OSD works perfectly, what I am saying is, I did a Serial version for the per-release of the 2.1 and that worked perfectly at the time.

Re: Questions regarding 2.1 GPS

Posted: Thu Dec 27, 2012 7:34 pm
by copterrichie
Here is the link to the post: viewtopic.php?f=8&t=1516&hilit=mega+serial&start=50#p13929

I stopped updating it because on one seemed interested at the time.

I THINK (need to verify) which ever serial port gains control over the processor, it does not release control for the processor to service the other requests.

Re: Questions regarding 2.1 GPS

Posted: Fri Dec 28, 2012 9:41 pm
by jevermeister
My OSD works normal in both cases. sometimes the gps data works even works. can I do something to help you finding it?

Re: Questions regarding 2.1 GPS

Posted: Fri Dec 28, 2012 10:13 pm
by copterrichie
jevermeister wrote:My OSD works normal in both cases. sometimes the gps data works even works. can I do something to help you finding it?


I will make an attempt this evening to go through the code and hopefully, have something to test tomorrow.

Re: Questions regarding 2.1 GPS

Posted: Fri Dec 28, 2012 10:32 pm
by jevermeister
kewl. looking forward.
remember:I use stock 2.1. No dev etc..

Re: Questions regarding 2.1 GPS

Posted: Sat Dec 29, 2012 12:09 am
by copterrichie
jevermeister wrote:kewl. looking forward.
remember:I use stock 2.1. No dev etc..


It appears to be fixed in R1293.

Re: Questions regarding 2.1 GPS

Posted: Sat Dec 29, 2012 10:14 pm
by jevermeister
Hmm,
I wonder when and how this has been fixed...
I remember, I read something about multiple serial ports at the same time :-/

Nils

Re: Questions regarding 2.1 GPS

Posted: Sat Dec 29, 2012 10:19 pm
by copterrichie
It works for me, I have GPS on 2, PPM on 1, modiDrone on 3 and the GUI on 0. And now that I think about it, I may be able to use the Define PPM on Throttle freeing up one of the serial ports. Hmmm

Re: Questions regarding 2.1 GPS

Posted: Sat Dec 29, 2012 10:23 pm
by jevermeister
with post1293 or stock 2.1?`

I use the same setup mobidrone/ppm/sergps

Re: Questions regarding 2.1 GPS

Posted: Sat Dec 29, 2012 10:26 pm
by copterrichie
The most recent development, I believe I am using R1292 but R1293 should be the same.