GPS RocketLocator offline map

Wayco said:

Reading Kurt's comments, I'm not even going to try to add maps to my Android phone. There are probably plenty of others here that feel the same.
Fantasiio, if you are having some trouble understanding the technical comments ksaves2 posts up, you are not alone.
I'm just glad my Rocket Locator app works, and I appreciate all the effort you have put into this product. Changing the altitude from meters to feet is a great idea, now if you could change the letters on the screen from white to black, I might be able to read them while walking across the desert in the AZ sunshine....

Click to expand...

Actually Wayne the way Francois has it setup it's pretty easy to do and from the looks of it, one doesn't have to use the caching feature. You wouldn't want to attempt to add many maps to a phone if the memory space is limited. If one has an
unlimited data plan, as long as they're in tower distance they'll have maps for tracking.

Francois gets this pulled off and I'll consider it as radical as when ham radio APRS/GPS tracking became available 17 years ago followed by some small trackers a few years later. Only problem with APRS tracking is one was looking
at $1000 to $2000 with all the bits and pieces it required back then. Kurt

ksaves2 said:

Francois gets this pulled off and I'll consider it as radical as when ham radio APRS/GPS tracking became available 17 years ago followed by some small trackers a few years later. Only problem with APRS tracking is one was looking
at $1000 to $2000 with all the bits and pieces it required back then. Kurt

Click to expand...

We've used APRS/GPS for our HABs for years. This past weekend I had a chance to put the EggFinder we've been using in the small scale 75mm Sugar Shot to Space sustainer that we've flown over 30,000'. We stopped receiving the EggFinder above 80,000'. We saw the balloon burst later when it reached 100,000' and regained contact with the EggFinder below 60,000' as it came down on chute.

Three possible reasons for losing reception:
1) We had been using Rocket Locator and were directly under the balloon when we lost contact...the antenna were now vertically aligned.
2) Even though I put the EggFinder in a styrofoam 'brick', it had been up in the subzero temperatures for over an hour.
3) At 80,000', it was too high up for the 3db gain antenna
and maybe 4) To save weight, we used our smallest 2s lipo battery to save weight since we were doing a ride along with a much larger experimental payload.

High Desert Rocketry said:

We've used APRS/GPS for our HABs for years. This past weekend I had a chance to put the EggFinder we've been using in the small scale 75mm Sugar Shot to Space sustainer that we've flown over 30,000'. We stopped receiving the EggFinder above 80,000'. We saw the balloon burst later when it reached 100,000' and regained contact with the EggFinder below 60,000' as it came down on chute.

Three possible reasons for losing reception:
1) We had been using Rocket Locator and were directly under the balloon when we lost contact...the antenna were now vertically aligned.
2) Even though I put the EggFinder in a styrofoam 'brick', it had been up in the subzero temperatures for over an hour.
3) At 80,000', it was too high up for the 3db gain antenna
and maybe 4) To save weight, we used our smallest 2s lipo battery to save weight since we were doing a ride along with a much larger experimental payload.View attachment 296814

Click to expand...

If the cold didn't get it, could be the 100mW output couldn't cut it. The treaty limits are 60,000 feet or greater than 1000knots/1200mph. Some chipsets will stop decoding above 60,000 feet even if they aren't moving fast. If you were still receiving at 80,000 feet, I'd think maybe it was the power output, antenna, cold soaked battery or any combination thereof that accounted for the problem. With a balloon perhaps a 900Mhz Yagi on the receive end might be doable
or get some gain with a patch antenna.

With the first version of the EggFinder a Ublox GPS could be easily substituted by accessing the 3.3V terminals on the board and soldering one wire to the pad where the Sirf IV module sat. I've done that with a circularly polarized Ublox chipset. Ublox has been known to work reliably above 80k. That wouldn't remedy the power output/antenna or cold soaking issues. A chemical hand warmer may or may not help. Kurt

Hi, I had a little spare time to check the problem of the offline map and, there is a easy workaround for now.
You have to manually create the folder 'mapcache' on the root of internal storage. It worked on devices I tried. And before it did not work, I had only gray squared.

ksaves2 said:

Francois, the key to testing is to download the map tiles, shut off the internet access, be it WiFi or cellphone and then fire up GPS Rocket Locator and see if it will write the map from cache.

Click to expand...

Don't worry, I did this test and it works very well. Even if you are online, it reads the images on storage.
During my tests, I deleted the content of the folder, but I never deleted the folder itself.
Apparently, there is a problem while creating the folder.

fantasiiio said:

Hi, I had a little spare time to check the problem of the offline map and, there is a easy workaround for now.
You have to manually create the folder 'mapcache' on the root of internal storage. It worked on devices I tried. And before it did not work, I had only gray squared.

Click to expand...

Hi Francois,
Ok, exactly where does one have to create the file? At /root/mapcache? Not an issue for myself as I have Wifi only devices. My Nexus 7 2013 is rooted and unlocked. For others who don't want to risk messing up the firmware on their phones this might be a problem as they might not be able to access the root directory.

I haven't been able to find where the GPS Rocket Locator executable lives on my device. Tried looking but I can't find it. If I can get the offline map cache to work, I won't care where the executable resides.:wink:

Getting the option to work with devices that aren't rooted or unlocked might be a consideration. Of course those with internet access through their phones and an unlimited data plan at their flying site don't have to worry and have been able to use the program since its
inception.

I've been tooling with the just released Debian "Jessie" based Pocket C.H.I.P https://getchip.com/pages/pocketchip
https://www.tested.com/tech/pcs/572345-maker-faire-2016-pocket-chip-49-portable-computer/

I was finally able to get the device to recognize the serial Bluetooth ports /dev/rfcomm"X" last night. Xastir runs finally with a B/T GPS and I will try to pair with the EggFinder receiver. Should work. Might be able to get YAAC to work too but alas, I thought this would be easy to do so other folks could reproduce it. Unfortunately, it isn't. Kurt

First, it's normal you don't find the executable. It's in a system folder and you can only access it with ADB (Android Debug).

For the folder, anyone with a file manager can create it. I did not say you need to be root. You have to put the file at the root of the folder...
Go to 'internal storage' with a file manager and create the 'mapcache' folder there.

edit:
Not the root folder of the system like /
Only root of internal storage

Worked for me. Pictures are now in the mapcache folder and are shown when offline.

However in my case the download stopped at 100% (339/340). "Cancel" didn't do anything so I had to kill the app and restart it.

Android 6.0.1

fantasiiio said:

First, it's normal you don't find the executable. It's in a system folder and you can only access it with ADB (Android Debug).

For the folder, anyone with a file manager can create it. I did not say you need to be root. You have to put the file at the root of the folder...
Go to 'internal storage' with a file manager and create the 'mapcache' folder there.

edit:
Not the root folder of the system like /
Only root of internal storage

Click to expand...

Sounds good. I just have to go to internal storage and type mapcache. That will be great. Leo got it working is reassuring and that will be the last hurdle I can see.

One question, will the program center the screen on the tracked rocket while in flight if the position packets are received? Yes, I'm aware of GPS limitations under G loads and Rf vagaries.
Reason I ask is when I tracked without a map, I had to zoom out to find the last known position of the rocket. Kurt

ksaves2 said:

Sounds good. I just have to go to internal storage and type mapcache. That will be great. Leo got it working is reassuring and that will be the last hurdle I can see.

One question, will the program center the screen on the tracked rocket while in flight if the position packets are received? Yes, I'm aware of GPS limitations under G loads and Rf vagaries.
Reason I ask is when I tracked without a map, I had to zoom out to find the last known position of the rocket. Kurt

Click to expand...

Nope, it does't track the rocket... lol
It could be a good feature

But, it's supposed to have a green line that is the rocket path. It may be useful to know where the rocket is.

Added mapcache folder and I now can get the maps offline...thanks!

fantasiiio said:

Nope, it does't track the rocket... lol
It could be a good feature

But, it's supposed to have a green line that is the rocket path. It may be useful to know where the rocket is.

Click to expand...

Yeah, when I used it without the map the line was hard to see but when I zoomed out I found the rocket position. With the map background will be easier to use. Kurt

fantasiiio said:

First, it's normal you don't find the executable. It's in a system folder and you can only access it with ADB (Android Debug).

For the folder, anyone with a file manager can create it. I did not say you need to be root. You have to put the file at the root of the folder...
Go to 'internal storage' with a file manager and create the 'mapcache' folder there.

edit:
Not the root folder of the system like /
Only root of internal storage

Click to expand...

Still no dice. I hit file manager and I get / and underneath there there is a bunch of file folders: acct, cache, config, d, data, dev, etc and a bunch of others. There is an "sdcard" folder that I assume is the memory card and also
a "storage" folder. Under sdcard which I presume is the internal storage, there are a pile of folders that have a variety of apps I recognize. I create a folder "mapcache" and I do see a bunch of .png files that I can see are maptiles after I download
some of the maps. Before shutting down, I shut off the Wifi so it will be off when I reboot. I restart and open GPSRL and it says going offline and no maps. So I try to download a greater number of zoom levels and I get a bunch of them stored but have the same problem as Leo. During one of the download sessions the download stopped.
I finally try some OSM maps. Again I see them in /sdcard/mapcache but when I start the program offline, the gps won't get a fix even. With the WiFi on, GPSRL gets a fix and pulls up the map offline with no issue. It shows me in a building 20 to 40 feet from where I'm actually seated. That's pretty derned good positioning. I stick it on the windowsill it's better.

I presume since the program is writing the .png files to the folder I have it located in the proper area? Problem is it still isn't pulling the map up from an off line startup. I just tried google maps again and get a lockup at 1356/1360 when trying to download a zoomlevel I killed it and went to my mapcache folder and there were .png files there. Ok, so I fired up GPSRL again with the WiFi on and it pulls up my position, I figured let's shutoff the Wifi and I could indeed scroll in and out of the limited zoomlevels I had on cache.
I shut down and restarted the program with the Wifi "off" and I get partial World Map with no position. Shutdown, turn the Wifi on and the program goes right to my position.

Observations:
1. Map downloading can be unreliable. I was standing under a high speed access point and got some lockups like Leo.
2. The maps will still not be displayed offline even if written to cache. GPSRL gives the indication it's going offline but only a partial map comes up and the GPS doesn't get a lock. I shut down and restart GPSRL with Wifi on and it goes right to my positions in 2 seconds. I don't know if I have /mapcache in the right directory but
it does store .png maptiles there.

The desired action would be to download maptiles of the desired area, shut down the program, proceed to the launch site without internet access, start up the program and have access to the maps that were stored on the device.

Just thought of something. Even though I said I used the /sdcard folder, this Nexus 7 2013 doesn't have a slot for a MicroSD card so
it's the internal memory . Kurt

I uploaded an update on google play for the creation of the folder mapcache.
It will be there in a few hours

fantasiiio said:

I uploaded an update on google play for the creation of the folder mapcache.
It will be there in a few hours

Click to expand...

Fantastic, I'll give it a go tonight. If that remedies the situation, I should be able to find out what I did wrong. Thanks again for all the work. Kurt

Ok, Had time to mess with it this afternoon. I went about it and deleted GPSRL under Android 5.1.1. Turns out I had the mapcache in the right location. Installed the updated version and I observed it worked with the cached maps
with the Wifi turned off. That's highly desirable.

Only issue I've observed is sometimes when caching the map for offline use the download indicator will get to the next to the last tile and lockup. I generally have to close, wait for the window to pop-up it's not working and close it.
Seems to keep most of the tiles in folder though. You have to have a good GPS lock to get the maps to come up. This is going to be great.

Francois, are there any cache size limitations? Would it be possible to scroll to a couple of sites, download the tiles and have then there when needed?

If this holds, GPS Rocket Locator, Altus Metrum's AltOs and AltosDroid with be the only "easily" accessible programs for folks to use for off line tracking with the option to use a photomap.
Nice to see if you've landed over that drainage ditch or barn.

Yeah there's several Ham Radio options that can be hacked as I've mention ad nauseam but I've been hoping for something easier for our flying brethren to use. Looks like Francois has done it.

The YAAC program for Windows tablets is progressing and hope it will be coming along soon. Pair a B/T GPS for local position, Pair the EggFinder receiver and go on an open source map.

Ok, Now I stuck GPSRL into a dual boot Chinese Android4.4.4/Windows 10 tablet and it works. Thing to remember if expecting to use it offline is the GPS will need to have a good lock and you have to have the maps downloaded to cache.
Expect with downloading that some of the maps will lockup with one last tile to download. Hit cancel and exit out of GPSRL. You'll have to wait for the popup, quit and start the downloads over from restarting the program. If push comes to shove out in the field, one can still track without a map. They just get two points and a line to follow and North is up. Kurt

A little off topic but I'm having problem with my software. It will only display the datum line and rocket path if I'm using open street map as the map provider and not when I use Google. Additionally instead of altitude, Max altitude, and distance it only displays altitude, altitude, altitude, up in the corner. Any suggestions on how to fix this? And I definitely agree with the comment that the information in the corner; distance, altitude and Max altitude need to be changed to a black font, it is impossible to read as it is.

sed6 said:

A little off topic but I'm having problem with my software. It will only display the datum line and rocket path if I'm using open street map as the map provider and not when I use Google. Additionally instead of altitude, Max altitude, and distance it only displays altitude, altitude, altitude, up in the corner. Any suggestions on how to fix this? And I definitely agree with the comment that the information in the corner; distance, altitude and Max altitude need to be changed to a black font, it is impossible to read as it is.

View attachment 297877

Click to expand...

I tried it and indeed, I have gray square with OSM, but only in my sector and not at all zoom level.. I'm wondering if it's a OSM provider problem or a software problem.
Also, on the MAX zoom level, all is gray, because OSM doesn't provide these tiles. You have to unzoom one level if you are at max.

For the fonts color, white is better on satellite map..
And for the altitudes, I don't have a clue. I'll check tonight.

I have some local google tiles saved and will fire up an EggFinder and drive around. I didn't notice any problem with the blue GPS on the map driving around.
My device is WiFi only so there is no internet link when I'm driving. I'll try testing tonight and see.

When using hacked APRS software like Xastir or APRSISCE/32 I can see the two positions hop-scotching together while driving around with the EggFinder on the dashboard feeding positions. Kurt

fantasiiio said:

I tried it and indeed, I have gray square with OSM, but only in my sector and not at all zoom level.. I'm wondering if it's a OSM provider problem or a software problem.
Also, on the MAX zoom level, all is gray, because OSM doesn't provide these tiles. You have to unzoom one level if you are at max.

For the fonts color, white is better on satellite map..
And for the altitudes, I don't have a clue. I'll check tonight.

Click to expand...

I appreciate the reply, but think you got it backwards. I don't get any datum line or rocket trace when I'm using the Google Map.

sed6 said:

I appreciate the reply, but think you got it backwards. I don't get any datum line or rocket trace when I'm using the Google Map.

Click to expand...

I just got to my destination with the Nexus 7 2013, the EggFinder LCD/HC-06 and EggFinder GPS tracker doing a drive-around with the Google Maps off line. I fired up everything at home off WiFi and discovered I didn't have the zoom level I needed. I had previously downloaded a "pile of tiles" but not the level I'd like. The maps I had came up fine off line. I went inside, downloaded and saved the local zoomlevel tiles I wanted. I zoomed out a bit, selected "follow me" and tracking was good.
I can confirm sed6's observation there is no datum line or track seen on the Google map itself. If I zoom in real low to where there is no maptile, I can see the track and the datum line against the white background. It's in there, it's just not being seen the same time the map is displayed. When I change zoomlevels I can see the track line (which is a dark navy in my case) and the datum "flash" briefly. I think this is a minor quirk but the program is still very usable. I did note that the rocket "red pushpin" position is updated quickly and the blue position GPS was a bit sluggish on my device. The Blue position seemed to update "slower" than in a previous version of GPSRL. I don't know, might just be my Nexus 7. The rocket EggFinder GPS position is "dead on" in the map whereas my device will be from 3 to 20 feet "off" ie. I can stand next to the Eggfinder GPS transmitter and the map will show me 20 feet away at it's worst. Hmmmmm, be sure to put a sufficiently loud beeper or screamer on the shockcord so I can hear it in tall grass. Some of this can be due to my local device GPS and I can try this with two other dual boot tablets I have that are dual Android/Windows to compare. Nonetheless the program is very usable in it's current state.

Remember, even if one misses an offline download of a particular zoomlevel, the program will still track the rocket against a white/light grey? background with the datum line seen. The technique is to zoom out a ways because the rocket could fly off the screen if the starting zoomlevel is too tight. I did that when I tracked one time without the map. I had to "zoom" out until I found the rocket and readjusted the position to where I want it. If one can "see" the datum line they can hit "follow me" at a tight zoomlevel and follow the line. Without the datum line seen on the map that's more difficult to do but if you get a sense of where the rocket is, it's easy to proceed in the right direction.
North is "up":smile:

Also depending on one's device, it might be hard to see the screen out in the sun as the datum line is thin and can be hard to discern. I put my device in a flat black painted box to act as a sunscreen which helps. Not perfect but helps. Some phones the screen disappears in the sun and is useless to use as a tracker.

Francois, you might want to change the presentation of the datum line so it is more prominent, perhaps use a thicker or "darker" line and of course see if you can get the track and datum displayed on the offline map field. Second, there are three Altitude indications in the upper left of the display. Sure it's easy to see which one is the rocket because the packets in the air will be higher than ground level. :wink: I think one of them needs to say "Distance" or "Distance From" and not altitude? Also is there a memory limitation for the map downloads? Some apps will only download so much for cache and then start over-writing. Is there a limit or is it only one's memory size that's the ultimate limitation?

Incidentally on a high speed internet line, I found the open source maps to be a slower download. Keep that in mind if one wants to download tiles in advance.

Again, many kudos for your program Francois. Besides Altus Metrum's tracking programs that only work with their devices, yours is the easiest to get going. Believe me, I've had help hacking away at three Ham Radio programs,
Xastir, APRSISCE/32 and YAAC and it was not easy to get them to work with these NMEA trackers (a.k.a. the EggFinder or NMEA devices). These other programs can display more information and generate all sorts of files like .kml on the fly which is great but doesn't help with the learning curve any. You've solved the problem of tracking a rocket on a map without having to be a Ham radio operator or stupendously computer savvy. I do Ham stuff,
have tracked with APRS trackers, used Altus Metrum's software with a Tele-GPS/Tele-BT and one is not missing much if they're a sport flier and simply want to find a rocket with GPSRL. I think it's great that the price of admission
has been dropped so dramatically in the past years for GPS tracking. Leads to everyone's enjoyment without having to worry about losing $$$$$ hardware.

Folks, if you're going to be using the program regularly, toss Francois a few $$$$ if you haven't already. Will ya? : https://rocketlocator.com/donations/donations/

Kurt Savegnago

sed6 said:

I appreciate the reply, but think you got it backwards. I don't get any datum line or rocket trace when I'm using the Google Map.

Click to expand...

I think it's a z-index problem. The line is drawn under the map. Probably easy to fix.
I'll fix it as soom I have time.

The problem with rocket path line (datum) is fixed. An update fill follow in few hours

fantasiiio said:

The problem with rocket path line (datum) is fixed. An update fill follow in few hours

Click to expand...

Yep, Fantastic! Very nice. I find with ground testing, it's best to keep moving around a bit when close in to the
NMEA tracker when lying it's on the ground. The two spots will then close in on each other eventually. I could be standing right next to the tracker on the ground and it would show a distance of 20 to 30 feet. Give it some time and the two points would eventually coincide.
Move around a bit in the area of the tracker and they will eventually get closer. Stick an aural beeper on the shockcord and all's one needs to do is get within 20 to 30 feet and your ears will tell you where to go.

Offline map downloads are great. WiFi only Android devices are acceptable now. Just download a mapset with all the zoom levels of the surrounding launch site that one desires and good to go.

One little quirk I've seen and it might be on my device only, is in the upper left corner where it's suppose to be
"distance to", "altitude of base station" and "altitude of the tracker/rocket" all simply are prefixed by "altitude".

Yeah, can figure it out easily as the "rocket" will show a flight level above the MSL of the base station and the "altitude" that is supposed to represent distance to the rocket/tracker will decrease as one progresses to the station.

I gotta tell you folks this is it for easy photomap tracking of rockets. I've messed with a bunch of programs and this is it. Get an Android phone or Android device that at least does WiFi and bluetooth and have at it. I have a WiFi only Nexus 7 2013 with a matte screen protector I carry in a cardboard shipping box, the inside of which is painted flat black to help with glare protection from the sun. You gotta phone with live internet? One can do the maps live as long as one has cell connection from their launchsite.

Aside from the correction of the listing in the upper left side of the screen with the distances all listed as "altitude"
I would recommend a screen option to follow the "rocket tracker" besides "me". Although that's a minor request. With the datum line that is now always on the screen, one can always zoom out and find the rocket easily.

I've found that when doing live tracking on a map, I'm more interested in where the rocket is at and the altitude.
I'd rather scroll out to see where I'm at in respect to the rocket but the live datum line helps in with centering the map on the last known rocket position if "track me" is selected.

The Ham radio apps that offer a little more utility are a B*T*H to setup. Xastir will record all the tracking data that can be pulled up in a mouse click and easily readable. Can also record a log directly in a .kml file no muss, no fuss.

APRSISCE/32 which is even HARDER to get going but will show a breadcrumb track with the altitude posted by each position! That program I really like but the MapQuest photomap is not longer available so it's no good for photomap tracking now. I cached the maps for my devices but if I go out of the area, I'll be out of luck. Only usable maps will be Open Source then.

Kurt

Managed to get this software working very well with my Eggfinder; however, I am getting the same problem as sed6 where I only see Altitude, Altitude, Altitude, in the upper right corner. Has there been a fix yet? I plan on taking this out tomorrow so the tracking/datum is really my only need, but figured I'd ask.

kyled921 said:

Managed to get this software working very well with my Eggfinder; however, I am getting the same problem as sed6 where I only see Altitude, Altitude, Altitude, in the upper right corner. Has there been a fix yet? I plan on taking this out tomorrow so the tracking/datum is really my only need, but figured I'd ask.

Click to expand...

Yes, I noticed that when the tracker and the local position are locked. I think the bottom one is "distance" between the two points. The others, one is the rocket and the other is local. Will be easy to determine as once packets come in from the inflight
rocket. It's obvious the one with height above field elevation will be the rocket. A minor mislabeling but the program is still useful as it is. Kurt

Another user suggestion here. After downloading maps for offline use, it's best to fire up the system a few days in advance and "see" if the mapfiles are still on ones device. I fired up my Nexus 7 2013 off line and scrolled to some of the sites
I previously had downloaded and in some cases the maps were gone. I did some cursory downloads and the offline zoomlevels returned. Weird.

Probably good to check a few days before one expects to fly off grid to make sure the desired mapset is on tap. Kurt

Has anyone successfully loaded a log file with Google Earth Pro?
Im always getting "Loaded no data."

How do I stop my Samsung G7 from saving map pictures???
two weeks ago I used my Eggfinder with the rocker locator app,,, it did work, absolutely perfect, took me right to the rocket NO Problem.
today I go look in my gallery for a picture and find I have 214 pictures of the area of the farm we launch at.

Any ideas ??

Good question. Me I want my device to save the images 'cuz I'm not using a phone with internet access.
I suspect you'll need to do a search to find the directory where the maptiles are stored and manually delete them.

You're right, My Nexus 7 2013 will list the tiles under photos but I don't mind since I have plenty of storage space left.
I could see a person not wanting to store maps locally but depending on the service provider, it might be cheaper
to keep them on the device as opposed to incurring charges every time you download them. Would depend upon
one's service contract. Kurt