AgOpenGPS - Page 5 - The Combine Forum
 2072Likes
 
LinkBack Thread Tools
post #41 of 3994 (permalink) Old 10-19-2016, 11:18 AM
Senior Member
 
Join Date: Sep 2009
Location: S. AB
Posts: 3,476
Mentioned: 6 Post(s)
Quoted: 863 Post(s)
If anyone wants information on getting RS232 GPS out of a GreenStar receiver, I can tell you how. Deere sells a $300 cable to do it, but it's not hard to splice into some wires up on the receiver and just use a cheap serial cable. And on the new GreenStar receivers, you can actually get serial from the back of the monitor I've been told.

torriem is offline  
Sponsored Links
Advertisement
 
post #42 of 3994 (permalink) Old 10-19-2016, 01:22 PM
Senior Member
 
Join Date: Sep 2009
Location: S. AB
Posts: 3,476
Mentioned: 6 Post(s)
Quoted: 863 Post(s)
So I couldn't get things to work quite right with my GreenStar receiver today. I configured it for 5 Hz update, 38400 baud, and for my other section controller I have GGA and VTG turned on. Looks like from the code you are using GGA and RMC. I turned that on too, and I can get proper data (both windows and Linux), but it's not working quite right. It takes it a couple of seconds to detect speed, and then as I drive around the yard the coverage doesn't mark like it should. In fact I can turn in a big circle and it ends up being at most a U shape on the screen. And when I stop moving, the speed remains about where it was and never goes to zero. Any ideas what is going on?

torriem is offline  
post #43 of 3994 (permalink) Old 10-19-2016, 02:14 PM
Senior Member
 
Join Date: Jun 2016
Location: Bannana Belt NW Saskatchewan
Posts: 261
Mentioned: 1 Post(s)
Quoted: 58 Post(s)
I have an old Trimble ez guide I'd like to rig for auto steer but I don't want to spend a bunch of money. Terrain compensation would be a plus but Mostly want it to steer me in a straight ab line and nothing more. My light bar has been updated as much as it can. Any thoughts.
Snapper22 is offline  
Sponsored Links
Advertisement
 
post #44 of 3994 (permalink) Old 10-19-2016, 05:20 PM Thread Starter
Senior Member
 
Join Date: Aug 2012
Location: Vermilion Alberta Canada
Posts: 5,617
Mentioned: 16 Post(s)
Quoted: 2460 Post(s)
Quote:
Originally Posted by torriem View Post
So I couldn't get things to work quite right with my GreenStar receiver today. I configured it for 5 Hz update, 38400 baud, and for my other section controller I have GGA and VTG turned on. Looks like from the code you are using GGA and RMC. I turned that on too, and I can get proper data (both windows and Linux), but it's not working quite right. It takes it a couple of seconds to detect speed, and then as I drive around the yard the coverage doesn't mark like it should. In fact I can turn in a big circle and it ends up being at most a U shape on the screen. And when I stop moving, the speed remains about where it was and never goes to zero. Any ideas what is going on?
Yes, too much data going in. Try it with RMC at 5 hz and everything else off. The serial port, and it can be changed to read faster is limited to about 8 or so reads per second. It needs the latitude and longitude from RMC and i think it keeps getting dropped. Speed also is just a direct read from RMC.

GGA is only used for elevation - which isn't used anyway. I probably should change it over to needing only GGA as that seems the most common. Thoughts?

Need to fix the serial port. Its a Microsoft Gem of misery in C#.

The speed not updating is an undocumented feature. the fix position has to move at least 0.5 meters before it will update the new position. this prevents drawing a million triangles while the GPS boffles around while you are standing still or going really really slow. I know i need to look at how that works. So there has to be a balance between recording enough positions while slow and way too many while really slow or stopped. I shall noodle on that. So good to have more eyes look at alpha version software.

Last edited by BrianTee; 10-19-2016 at 05:47 PM.
BrianTee is online now  
post #45 of 3994 (permalink) Old 10-19-2016, 05:24 PM Thread Starter
Senior Member
 
Join Date: Aug 2012
Location: Vermilion Alberta Canada
Posts: 5,617
Mentioned: 16 Post(s)
Quoted: 2460 Post(s)
Quote:
Originally Posted by Snapper22 View Post
I have an old Trimble ez guide I'd like to rig for auto steer but I don't want to spend a bunch of money. Terrain compensation would be a plus but Mostly want it to steer me in a straight ab line and nothing more. My light bar has been updated as much as it can. Any thoughts.
I have one of those too, not the most accurate. You swear your driving in a straight line but the light bar keeps telling you strange things. They are quite drifty and can vary quite a bit per pass.

But they do work for AOG. Set the serial port to RMC at 5 HZ and 19,200 baud and hook up the usb to serial cable and voila, you have mapping and a light bar.
BrianTee is online now  
post #46 of 3994 (permalink) Old 10-19-2016, 06:46 PM
Senior Member
 
Join Date: Sep 2009
Location: S. AB
Posts: 3,476
Mentioned: 6 Post(s)
Quoted: 863 Post(s)
Do you mean you should change your code to only require RMC? RMC has the speed and heading. I think it would be nice if your code could handle a data stream at 5 Hz with multiple message types enabled, even ones you don't need or care about. There's no reason the computer can't handle it if you can figure out how to make C# do it.

The Raven Smartboom uses GGA and VTG. From what I can read, VTG is similar to RMC, except that it uses metric for speed instead of knots. I dunno.

I'll give it another test tomorrow with just GGA and RMC on.
torriem is offline  
post #47 of 3994 (permalink) Old 10-19-2016, 07:34 PM Thread Starter
Senior Member
 
Join Date: Aug 2012
Location: Vermilion Alberta Canada
Posts: 5,617
Mentioned: 16 Post(s)
Quoted: 2460 Post(s)
No, the code uses RMC. Its is all it needs to map and work. Its not too hard to switch off a few sentences in the JD setup. But yes, would be nice if it could read faster.

I'm not sure where the speed limitation is. I'm using readLine() for reads of the port which waits for an entire line to be read before dumping it into a single message and then hand it off to the NMEA parser to determine if its a real sentence, what type of sentence like GGA RMC, do a complete checksum to make sure its valid, parse it, then store each item, or discard the line if its garbage or something other then GGA or RMC . That way i don't need to search a string and put together all the pieces on top of it all too.
BrianTee is online now  
post #48 of 3994 (permalink) Old 10-19-2016, 07:52 PM
Senior Member
 
Join Date: Sep 2009
Location: S. AB
Posts: 3,476
Mentioned: 6 Post(s)
Quoted: 863 Post(s)
Was just checking to see what x86 single-board computers I could find that could run Linux (wine requires x86) or Windows and found this one that will be available soonish:
UDOO X86 - UDOO

Looks very appealing for this application because it has built-in arduino-compatible circuitry for doing I/O. I assume it's a dedicated Atmel processor that you can talk to from the main OS somehow. Combine this with a touch screen in a little case and you'd have a nice unit.

Of course LattePanda is another good choice. It also has en embedded Atmel processor for doing I/O.

Time to add a 3d printer and CNC milling machine to my list of winter projects. Ha. I will never get anything done at this rate.
BrianTee likes this.

Last edited by torriem; 10-19-2016 at 07:57 PM.
torriem is offline  
post #49 of 3994 (permalink) Old 10-19-2016, 09:11 PM
Senior Member
 
Join Date: May 2011
Posts: 828
Mentioned: 0 Post(s)
Quoted: 151 Post(s)
Quote:
Originally Posted by BrianTee View Post


Perhaps I should write up an NMEA and serial port tutorial.
When you get time, that would be fantastic
adsinaus is online now  
post #50 of 3994 (permalink) Old 10-20-2016, 04:18 PM
Senior Member
 
Join Date: Nov 2013
Location: South west vic (aus)
Posts: 318
Mentioned: 0 Post(s)
Quoted: 67 Post(s)
What would be a suitable GPS receiver that isn't complete rubbish? Are you doing testing with a standalone receiver or just streaming nmea out of an ezy guide or starfire?
Thanks

Swoopa_au is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Combine Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome