WAAS and Magellan GPSr's

[+RRLover]

So what this is all telling me, is that if I have a Explorist 500 and it is trying to get a fix on sat 120 & 122 it will never get WAAS ever again right?

Update to european firmware 2.57 you'll get WAAS back. Backup your basemap first though.

 

Tried the european update but am still reading sats 120 and 122. anyone have any tips?

Which model?

Which firmware was on it?

Which serial # brackets is it in.

I don't think there's a serial # issue w/XLs but the numbered series eXplorists sometimes get 'bricked' if

they're too high! Sorry don't remember the good or bad number series though.

 

Did you do a "reset all" before doing the firmware up-date, and then again, afterwards?

 

Norm

[+CipparroneClan]

So what this is all telling me, is that if I have a Explorist 500 and it is trying to get a fix on sat 120 & 122 it will never get WAAS ever again right?

Update to european firmware 2.57 you'll get WAAS back. Backup your basemap first though.

 

Tried the european update but am still reading sats 120 and 122. anyone have any tips?

Which model?

Which firmware was on it?

Which serial # brackets is it in.

I don't think there's a serial # issue w/XLs but the numbered series eXplorists sometimes get 'bricked' if

they're too high! Sorry don't remember the good or bad number series though.

 

Did you do a "reset all" before doing the firmware up-date, and then again, afterwards?

 

Norm

 

eXplorist 500 didn't do the reset but will try that tonight when I get home to my pc and try to find the basemap to back up first.

[red1one]

In each unit, AFTER the wipe, there were two files in the unit's memory: an approximately 16MB file that is the basemap, and a much smaller file (approximately 256KB) with a name like CRITMEM.MEM (The names were different for both units, but the sizes were very close.) It has occurred to me that if I, as a programmer, had to keep track of what satellite is sending a WAAS signal, I would probably store it in a file with name like CRITMEM.MEM. I would also probably store tracks and user-preferences and such in there, and it might get bigger with continued use. (I'm wondering if there are more files are stored in a unit that hasn't had a memory wipe, and what they are.)

 

So here's my suggestion: what if that small file were copied from a unit that got the WAAS-change notification to a unit that didn't? (Your post mentioned a friend with a more accurate GPS.)

and my request is that anyone with a WAAS-working Meridian send me a list of files and their sizes living in memory on their unit. (That data has to be in there somewhere, it's just a matter of finding it.)

 

I have a Meridian Color with v5.36 and another with v5.40 and I would be willing to update to another firmware if need be and if available. Does someone out there have a MeriColor with 5.40 or 5.36 and working WAAS (correct satellite numbers)? I would be willing to try uploading a CRITMEM.MEM file into my unit to see if this takes care of the WAAS-satellite problem.

There are numerous links to the How-to-backup-a-basemap on the web. Just make sure to ignore the part with Clear-All.

 

GWPouch

 

I tried replacing the CRITMEM.MEM and FIRMWARE.BIN files with versions from my friends Explorist XL but it did not work. The old and new CRITMEM.MEM files were of different size. After restarting the file was always back to it's old size. The european firmware update 1.55 fixed the problem for me. Good luck.

That sounds like the software detected that the format of CRITMEM.MEM was wrong for its platform or version and re-wrote the default values.

 

If they are storing the binary information in a way that's close enough to the original WAAS almanac messages, I might be able to poke around in those files and find something to tweak. If anyone's interested, I can send you my email address.

 

But if it has some kind of checksum or security/integrity protection in there, I'm probably out of my league.

 

Were you ever able to retrieve anything from the CRITMEM.MEM files?

 

I am currently looking at them on a binary level, and trying to decipher them. Any luck at all?

 

Thanks

[+trainlove]

Were you ever able to retrieve anything from the CRITMEM.MEM files?

 

I am currently looking at them on a binary level, and trying to decipher them. Any luck at all?

 

Thanks

No info, no time. I think that finding 600 caches since then was more important to me, and screwing up my ratios of 'other than traditional finds' vs traditional finds.

I don't think anything important s.i.c. is stored in Critmem.mem, but could be wrong. At least there seem to be no PRN numbers in there.

I may re-partake in my mission to solve this (unimportant) problem once again. Unimportant since loss of WAAS Iono corrections does not seem to really matter at all. More important is to not have the GPS clock time be far off from WWV master time, and/or not to have BadRTCR in secret menu [00] when it alternates showing that and other things.

 

Ray.

Edited October 23, 2008 by trainlove

[+Frodo_Underhill]

While I was walking to from one cache to another this afternoon I was thinking about the WAAS problem with the pre-Triton Magellan GPSr. As I understand it, if the GPSr was on-line when the WAAS satellites where changed and it received the updated satellite info from the old satellites and its memory has not been rest since that time, then it is capable of receiving the WAAS corrections from the new satellites. Now if the memory is cleared on that GPSr, the factory defaults from ROM are loaded into memory and the GPSr will not recognize the new satellites.

 

There is something in the memory of that WAAS capable GPSr before it is reset that allows it to identify the new satellites. It is doubtful that anyone will ever be able to reverse engineer the firmware – just too complicated. However has anyone ever thought of dumping the entire contents of the GPSr memory to a file of a GPSr that recognizes the new WAAS satellites and then taking that memory dump and loading it into a GPSr that does not recognize the WAAS satellites? It’s a brute force memory. Might be crazy enough to work. You would need a program to access all of the memory within the GPSr. None of the built in functions are going to handle this. We would need a small program that could be loaded into the GPS to dump the data to the serial port and then another to receive the data in the next GPS.

 

Some one a while back worked on porting uClinux to the Magellan Meridians and got as far as getting a program to read the buttons to run. However the site with this information is no longer active so that is gone.

 

So the vision would be to dump the data from one WAAS capable GPS and package it with a program to install this data on a non-WAAS capable GPS and restore WAAS. Crazy idea or not? What do you think? And is anyone capable of pulling this off?

[+Klemmer]

Definitely not a crazy idea. I still use my old Maggy Meridian for certain tasks (e.g. multiple 500 waypoint files), and would love to have it capapble of using WAAS corrections once again.

 

I would support such an effort. I'm not capable myself, unfortunately. I know a couple hot-shot young software techie types that might help. Is uClinux the operating system that the Meridians used? Or is it just one that will run on that hardware (so I can ask the right questions of my software types)?

 

Obviously, I would be OK with beta testing. I have other primary GPSr's I could use (Garmin, Delorme). If my maggy got permanently "bricked", I wouldn't cry for too long.

[+RRLover]

Definitely not a crazy idea. I still use my old Maggy Meridian for certain tasks (e.g. multiple 500 waypoint files), and would love to have it capapble of using WAAS corrections once again.

 

I would support such an effort. I'm not capable myself, unfortunately. I know a couple hot-shot young software techie types that might help. Is uClinux the operating system that the Meridians used? Or is it just one that will run on that hardware (so I can ask the right questions of my software types)?

 

Obviously, I would be OK with beta testing. I have other primary GPSr's I could use (Garmin, Delorme). If my maggy got permanently "bricked", I wouldn't cry for too long.

PM Trainlove and see how his efforts are going, last I read he was taking a hiatus.

 

Norm

[+GeoDad6]

It Worked. A while back, my Explorist 210 locked up, and after getting it re-powered, I lost everything, including my WAAS. I just downloaded and installed 2.57 and it worked. I got my WAAS back as well as some really cool new screens that look somewhat similar to those I have seen on Garmin E-Trex models. I gotta say, Thanks to everyone here for the workaround.

 

Some points to not:

Please back-up a copy of your Basemap.mgi file from your explorist before doing this. Once the new file is uploaded, just explore the GPSr device , basemaps, and remove the basemap that was installed with the new firmware (unless you're actually in Europe, then keep it as is). Now drag the old basemap to your basemaps folder on your GPSr and SheBangs!!!

[+trainlove]

Good news everyone.

Check http://forums.Groundspeak.com/GC/index.php?showtopic=210652 for details.

Info and links will be provided when I'm satisfied with the ease of this fix.

 

Since it's you peronally modifying your firmware, it can be dangerous and you might make a brick out of your GPS. But I'm testing completely before I supply any details, and there will be grave warnings on all the possibilities in whatever I publish.