Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Jul 28, 2012, 03:23 AM
Registered User
Joined May 2011
3 Posts
I am using the OSD for a FPV balloon tracker. I have 2 questions.
1. Is there a way to display the GPS coords, that can be displayed in top left just below the battery voltage while flying?
2. The GPS coords are out by 3-7 minutes. Is there any way to correct these incorrect GPS coords.
Randyy is offline Find More Posts by Randyy
Last edited by Randyy; Jul 28, 2012 at 03:25 AM. Reason: typos
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 28, 2012, 03:37 AM
Registered User
Joined Apr 2012
68 Posts
I'm just getting started in FPV and purchased the G-OSD when I bought my video transmitter etc. After setting it all up I decided that it was not a very good device and put it in the cupboard. After seeing this thread I have re-flashed it and it is soo much better. Has all the basic features I need which is awesome. The only thing I am having trouble with is the refresh rate.

I've got is setup on a Tricopter and when I go vertical it takes a very long time before it updates with the altitude and usually I am already on my way back down. It is still 100% better than stock but I think I need to invest in something with better hardware to give me better resolution.

Any ideas?
pjman is offline Find More Posts by pjman
Reply With Quote
Old Jul 28, 2012, 04:40 AM
FPV only!
YureZzZ's Avatar
Russian Federation
Joined Dec 2010
71 Posts
Quote:
Originally Posted by Randyy View Post
2. The GPS coords are out by 3-7 minutes. Is there any way to correct these incorrect GPS coords.
That GPS is kind low quality, I've tried filtering its data with no good results. Mine sometimes doesn't even find any sats! So if you really need precise coords - get MTK GPS module and connect it instead.
YureZzZ is offline Find More Posts by YureZzZ
Reply With Quote
Old Jul 28, 2012, 06:09 PM
Registered User
Joined Dec 2010
124 Posts
Quote:
Originally Posted by YureZzZ View Post
That GPS is kind low quality, I've tried filtering its data with no good results. Mine sometimes doesn't even find any sats! So if you really need precise coords - get MTK GPS module and connect it instead.
Will the MTK GPS work with CL-OSD?

Someone says here:

http://www.rcgroups.com/forums/showt...490446&page=95

That it will not.
damage2008 is offline Find More Posts by damage2008
Reply With Quote
Old Jul 30, 2012, 03:06 PM
Registered User
Joined Dec 2011
138 Posts
wohoo, after using my g-osdII with stock firmware for months, i finally got around to flash it! i made a flashing jig so i didnt have solder on any leads that will add to the wire rats nest in my fpv backpack. i have not tried it in the field yet, but worked beautifully on my porch.

i'm interested to see if by any chance reflashing the osd will improve the GPS accuracy. for some odd reason this osd has always indicated my altitude as being about 900 feet, actual value is over 1100. same with lat/long coordinates: even when entered properly in google maps, it is consistently off by about 3000 feet. it couldnt be the GPS unit itself being off, could it? i've assumed its some sort of bug in the OSD itself, or in the communication betweeen the GPS and the OSD.
fpvwannabe is offline Find More Posts by fpvwannabe
Reply With Quote
Old Jul 30, 2012, 03:15 PM
Way to many airplanes!
Canada, QC
Joined Oct 2009
5,453 Posts
G-OSD display lat/lon in GGA format. Check for the different ways to display GPS coordinates. To use google, you have to do a translation. (basically, one way is decimal, and the other one is minutes seconds etc)
RealGambler is offline Find More Posts by RealGambler
Reply With Quote
Old Jul 30, 2012, 03:40 PM
Registered User
Joined Dec 2011
138 Posts
Quote:
Originally Posted by RealGambler View Post
G-OSD display lat/lon in GGA format. Check for the different ways to display GPS coordinates. To use google, you have to do a translation. (basically, one way is decimal, and the other one is minutes seconds etc)
gambler,

i was aware of the different formats, although i am not 100% i did the translation properly. nevertheless, the format issues can hardly explain the altitude consistently being off by 200+ feet, can it?
fpvwannabe is offline Find More Posts by fpvwannabe
Reply With Quote
Old Jul 30, 2012, 03:52 PM
Registered Aircraft Offender
Truglodite's Avatar
Carmichael, CA
Joined Feb 2007
3,513 Posts
I have been meaning to try this (config.h):

//GPS
#define GPS_GOOGLE_FORMAT
//#define GPS_DIYD //Use DIYD/APM binary protocol (Thanks to David Collett)

I haven't had time to test it, what I am after is having Google GPS coords displayed at all times, just in case something happens and I need to use my phone and DVR to locate an aircraft. I know it's already been discussed here... there's even compiled versions, but I want to learn the how/why.

callelj or whoever knows... regarding TEXT_COMPASS_ENABLED... is it big or what?:

My m88pa chip is 98.4% full with the following changes: NTSC, Volt2, GSODII fix, Imperial, commented out RSSI sensor, home_set_at_fix, time_hour, and callsign. When I add the text compass, it goes to 100.2%. Close, but no cigar. I tried commenting out the RSSI sensor to make room, but no effect. I suppose I'd be willing to give up time and callsign for the compass, and maybe even have to press a botton to set home. But that may not be enough, and I'd rather keep those features if possible. Any ideas on how I can save that 0.2% to squeeze in the text compass, without chopping down my current feature set?

Thanks,
Kev

[edit: I answered my own question. I have to choose between TIME_HOUR_ENABLED or TEXT_COMPASS_ENABLED, because both won't fit on the chip together. I'm using a Sony NTSC 520TVL ccd, so we'll see if my compass hex shows garbage without changing to 22 chars... which I understand also shifts the display to the left.]
Truglodite is offline Find More Posts by Truglodite
Last edited by Truglodite; Jul 31, 2012 at 08:54 PM.
Reply With Quote
Old Jul 30, 2012, 04:00 PM
Registered Aircraft Offender
Truglodite's Avatar
Carmichael, CA
Joined Feb 2007
3,513 Posts
Quote:
Originally Posted by fpvwannabe View Post
gambler,

i was aware of the different formats, although i am not 100% i did the translation properly. nevertheless, the format issues can hardly explain the altitude consistently being off by 200+ feet, can it?
I think GPS data needs to be accurate for altitude calcs, unless you use something else to measure, like a baro and/or sonar.

Kev
Truglodite is offline Find More Posts by Truglodite
Reply With Quote
Old Jul 31, 2012, 01:38 PM
Registered User
Argentina, BA, Martínez
Joined Apr 2010
88 Posts
Hello

I have trouble with TEXT_LINE_MAX_CHARS , I have an NTSC 540tvl camera and seems only to be stable with 22 chars (but coordinates show truncated amd text compass too, its too short line), anything else is garbage like in attached video... (i uncommented line COLORSYSTEM_NTSC because needs ntsc)
what can i do in the code to show NTSC as expected?

I had to compress all the info to the left , because wanted (compass and lat lon coordinates always present) just because can only use 22 chars ... as shown in second video..


thanks a lot!!

cl osd error (0 min 13 sec)


CL OSD coordinates and compass always ON but compressed to 22 chars NTSC GOSD2 (0 min 19 sec)
marce002 is offline Find More Posts by marce002
Last edited by marce002; Jul 31, 2012 at 03:31 PM.
Reply With Quote
Old Jul 31, 2012, 02:45 PM
Registered User
cyhyam's Avatar
Highland, CA, USA
Joined Jan 2001
1,108 Posts
I have the G-OSD II. Will changing the GPS module to this one, 10Hz GPS LS20033, (BEVRC) improve the update speed or accuracy. Is there anything in the code that will improve it?
cyhyam is offline Find More Posts by cyhyam
Reply With Quote
Old Aug 02, 2012, 04:21 AM
Registered Aircraft Offender
Truglodite's Avatar
Carmichael, CA
Joined Feb 2007
3,513 Posts
GPS Calibration

I noticed my GOSDII with closd is actually decent as far as the precision goes, only the displayed coordinates were consistently off by the same amount, which was about a mile away (good luck recovering with a DVR if it gets lost!!!). I fixed this with the following changes, and now have the real position displayed on my screen. Now I'm a happy boy to spend $50 on another!

Insert the code at line 256 of text.h so it looks like this:
Code:
#ifdef GPS_GOOGLE_FORMAT
  uint32_t min = number - (hour * 1000000);
  min = (min * 100)/60;
//Calibrate Google GPS Coords
  if (numberLat) {
	  min = min + FUDGE_GOOGLE_LAT;    //Local calibration of Google GPS Lat (Truglodite)
  }
  else {
	  min = min + FUDGE_GOOGLE_LON;    //Local calibration of Google GPS Long (Truglodite)
  }
Also add this at line 146 in config.h:
Code:
//GPS
#define GPS_GOOGLE_FORMAT //**
//#define GPS_DIYD //Use DIYD/APM binary protocol (Thanks to David Collett)
#define FUDGE_GOOGLE_LAT 7382 //Local calibration of Google GPS Lat (Truglodite)
#define FUDGE_GOOGLE_LON 4728 //Local calibration of Google GPS Long (Truglodite)
...my GOSD II required +0.007382*N, and +0.004728*W of correction. You will likely have to change those numbers to match the error on your particular unit. I'm curious to find if others have the same GPS error. You can tell I'm a newb, because I didn't use #ifdef in text.h.

I attached a zip of my CL-OSD directory. Compiled GOSDII hex+eep files are in the G-OSD folder. Basic features are NTSC, imperial, V1, V2, home set with button only, no rssi, Google GPS with my personal error corrections, 20sec stats delay, coords always on, 10.8V alarms (both), 1mile ALT & SPD alarms, 70mph alarm.

Oh yeah, I've searched this and nothing came up. So if you want Google GPS coordinates always displayed, insert this in line 131 of layout.h (doesn't work with TEXT_COMPASS_ENABLED):
Code:
#ifdef TEXT_COMPASS_ENABLED		  
		  printCompass(gText[textId], 7, gGpsLastValidData.angle, 19); // Lower compass part
#else 
          pos = printGpsNumber(gText[textId], pos+4, gGpsLastValidData.pos.latitude, 1); // GPS position in place of text compas (Truglodite)
          pos = printGpsNumber(gText[textId], pos+2, gGpsLastValidData.pos.longitude, 0);
#endif //TEXT_COMPASS_ENABLED
DJI 450 FPV Quadcopter (3 min 4 sec)


Hope this helps a fellow newb,
Kev
Truglodite is offline Find More Posts by Truglodite
Last edited by Truglodite; Aug 03, 2012 at 07:40 PM.
Reply With Quote
Old Aug 02, 2012, 06:11 AM
FPV only!
YureZzZ's Avatar
Russian Federation
Joined Dec 2010
71 Posts
Quote:
Originally Posted by damage2008 View Post
Will the MTK GPS work with CL-OSD?

Someone says here:

http://www.rcgroups.com/forums/showt...490446&page=95

That it will not.
Then why do we have this line
Quote:
#define GPS_DIYD //Use DIYD/APM binary protocol (Thanks to David Collett)
in the source code?
YureZzZ is offline Find More Posts by YureZzZ
Reply With Quote
Old Aug 02, 2012, 12:43 PM
Registered Aircraft Offender
Truglodite's Avatar
Carmichael, CA
Joined Feb 2007
3,513 Posts
YureZzZ, are you using a MTK GPS? I'll put a DIYD GPS on my list if I know I can get it to work right. Just wire it up and uncomment the line? Wiring pics would be great too, but I can probably figure that out myself.

Kev
Truglodite is offline Find More Posts by Truglodite
Last edited by Truglodite; Aug 02, 2012 at 12:48 PM.
Reply With Quote
Old Aug 02, 2012, 01:01 PM
Registered User
Joined Dec 2010
124 Posts
Quote:
Originally Posted by YureZzZ View Post
Then why do we have this line
in the source code?
Dunno...... I'm a noob at this and was just restating what I read!

So will a MTK GPS work?
damage2008 is offline Find More Posts by damage2008
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Super OSD ($90): Open Source Graphic OSD: Vario, 6xADC, Games, Datalog, Dual Video tom66 FPV Equipment 1928 May 24, 2014 11:07 AM
Discussion Open Source Remote Control System (OSRC) Gizmoman31 Radios 152 Apr 24, 2012 06:01 PM
Discussion Open source OSD for FPV UFO_MAN FPV Talk 75 Sep 07, 2011 02:03 PM
Question Open Source Octo Design Available...Looking for someonw who can cut a copy for me... Schatham421 Multirotor Talk 14 Apr 12, 2011 05:22 PM