GPS Rocket Locator for android (Now released !)

[Area66]

I searched on the net for Canadian Amateur Radio Bands and the reserved frequencies for this band are 430mhz to 450mhz. We can setup the apc220 to 418mhz to 455mhz. If we set it to 418mhz, we are not in the HAM band and no more illegal.
.

You can't use it as you want , check Paragraph E

1- the maximum transmision time is 1 sec with not less than 10 secondes betwen transmission

2- the output power as to be limited to 50mv/m so it's for very close range useless for rocketery

 

[Derek]

I searched on the net for Canadian Amateur Radio Bands and the reserved frequencies for this band are 430mhz to 450mhz. We can setup the apc220 to 418mhz to 455mhz. If we set it to 418mhz, we are not in the HAM band and no more illegal.

For those who don't want the apc220, there is the xbee pro for $50-60 each unit instead of $35 for 2 units.
There is another HAM band on 902mhz to 920mhz and the xbee pro 900 operate in 902 - 928 MHz, I'm not sure for this one.

I think we can use the apc220 without problem.

it looks like at 418 mhz you can use it without a license, but there appear to be power limits at that frequency. they don't come out and tell you what the max power is because it is too dependant on the antennas. you're supposed to measure it to see if it complies. see here:

https://www.rfm.com/products/apnotes/an0900.pdf

further down in the doc they talk about typical outdoor ranges of about 300 ft for remote controls, and 100 ft for other applications.

in the us, the xbee modules I use (xbee pro 900hp) are $39 each, so your modules are cheaper but these xbee modules have 250 mw output. It looks like in canada they cost a little more (~$44).

I hope to play around with your sw a little more today to see how it works. If you are looking to add some features, then I'd suggest allowing the user to select units in feet or meters.

 

[Derek]

You can't use it as you want , check Paragraph E

1- the maximum transmision time is 1 sec with not less than 10 secondes betwen transmission

2- the output power as to be limited to 50mv/m so it's for very close range useless for rocketery

Thanks Gerard. I couldn't find as clear a definition of the limits as you did. I saw the time restrictions, but I think you could work around that.

 

[Derek]

There is another HAM band on 902mhz to 920mhz and the xbee pro 900 operate in 902 - 928 MHz, I'm not sure for this one.

the 900 mhz xbee modules are designed to operate in the ism band in north america. no license is necessary.

 

[fantasiiio]

If you are looking to add some features, then I'd suggest allowing the user to select units in feet or meters.

Yes, good idea.
Two other important features not yet implemented:
-Use compass to rotate the map in the direction you are pointing . (For now, the map rotate in the rocket direction, but you are an arrow on the map)
-For now, when the rocket land on the ground and you want to begin search you rocket, you have to turn off your wireless to bluetooth converter because the camera still follow the rocket and you cannot move / unzoom on the map. So, I have to implement a 'Stop following' feature.

 

[Derek]

Yeah, I just tried it and I see what you mean about not being able to zoom.

It also seems to be having issues receiving data from the rocket. I only gets beeps every 10 seconds or so. The rocket is sending its position every second. My other apps don't have this problem.

The other issue I noticed is the position where you put me on the map is one street over from where I actually am. However if I use google maps to see my position, it is pretty much right on. You might want to display my lat/long location so I can double check it.

It also occasionally thinks the rocket teleported to africa and back. I end up with blue lines radiating out from my location. I think some type of filtering is needed to throw out obviously bad locations. I've seen this too when tracking my rockets with google maps. You would think the checksum in the nmea string would prevent this from happening, but it doesn't.

But it more or less works besides those few issues.

Great job!

 

[fantasiiio]

Yeah, I just tried it and I see what you mean about not being able to zoom.

It also seems to be having issues receiving data from the rocket. I only gets beeps every 10 seconds or so. The rocket is sending its position every second. My other apps don't have this problem.

The other issue I noticed is the position where you put me on the map is one street over from where I actually am. However if I use google maps to see my position, it is pretty much right on. You might want to display my lat/long location so I can double check it.

It also occasionally thinks the rocket teleported to africa and back. I end up with blue lines radiating out from my location. I think some type of filtering is needed to throw out obviously bad locations. I've seen this too when tracking my rockets with google maps. You would think the checksum in the nmea string would prevent this from happening, but it doesn't.

But it more or less works besides those few issues.

Great job!

For your 10 seconds between beeps, can you tell me if you can receive data even if it doesn't beep ? It beep in the NMEA parser, only when it receive a GPGGA sentence. If the NMEA parser doesn't receive anything, it's probably because the android doesn't receive it.

For your position (Blue arrow), I only set mMap.setMyLocationEnabled(true) and the blue arrow appears. It's a google map feature, all code is from google map api. Probably the gps data is not accurate enough. I had this problem when I tested inside my house.

For the teleportation to affrica, this is latitude 0 and longitude 0, probably a bad gps packet. And yes, good idea to filter bad locations, but I never experienced this.

In general, do you like the idea to track your rocket with google maps ?

 

[kruland]

Hi guys,

I can't seem to get the application to run on my Nexus 7 (JB) or RazorM (ICS). I dies because of the google maps classes not found (from the main view).

Honestly, the maps bit is cool, but it wouldn't help me find my rockets. I launch in places where there is very poor data service. I'd rather have bearing & distance.

Kevin

 

[Derek]

For your 10 seconds between beeps, can you tell me if you can receive data even if it doesn't beep ? It beep in the NMEA parser, only when it receive a GPGGA sentence. If the NMEA parser doesn't receive anything, it's probably because the android doesn't receive it.

For your position (Blue arrow), I only set mMap.setMyLocationEnabled(true) and the blue arrow appears. It's a google map feature, all code is from google map api. Probably the gps data is not accurate enough. I had this problem when I tested inside my house.

For the teleportation to affrica, this is latitude 0 and longitude 0, probably a bad gps packet. And yes, good idea to filter bad locations, but I never experienced this.

In general, do you like the idea to track your rocket with google maps ?

Wait, I'm the blue dot and the rocket is the red arrow/pointy bubble thing? I though it was the other way around. To me, it makes more sense to draw the circle of uncertainty around the rocket, not me. I don't really care if the phoen doesn't have a perfect fix for me. I know where I am.

I think the map view is very useful because you can't always walk directly towards the rocket. There could be a lake, dense trees, cliff etc. and it would be nice to see that before you head off.

I don't have any way of knowing if I'm getting data in your app. In the app Kevin wrote, he has a log screen that shows the messages coming in. It would be nice if you had this too for debug purposes.

 

[Derek]

Hi guys,

I can't seem to get the application to run on my Nexus 7 (JB) or RazorM (ICS). I dies because of the google maps classes not found (from the main view).

Honestly, the maps bit is cool, but it wouldn't help me find my rockets. I launch in places where there is very poor data service. I'd rather have bearing & distance.

Kevin

I couldn't get the map to work on my ics phone. I haven't tried it on my nexus 7. sorry.

edit:

did you put android-support-v4.jar in the project's libs directory? Do you have google-play-services_lib as an eclipse project and linked in the rocketlocator project?

 

[fantasiiio]

Hi guys,

I can't seem to get the application to run on my Nexus 7 (JB) or RazorM (ICS). I dies because of the google maps classes not found (from the main view).

Honestly, the maps bit is cool, but it wouldn't help me find my rockets. I launch in places where there is very poor data service. I'd rather have bearing & distance.

Kevin

You have to import a project in your workspace: google-play-services_lib that is in folder android_sdk/extras/google/google_play_services/libproject/google-play-services_lib
and reference it in your project. You probably have an error on that lib ?

For your poor data service problem, when you are at home, you can zoom in the place you launch your rockets, the map tiles will be saved in cache and no more need internet on the field. I don't event have the data service on my phone, I only use wifi at home.

If there is a compatibility issue with ics, I'll try to resolve it.

 

[fantasiiio]

Wait, I'm the blue dot and the rocket is the red arrow/pointy bubble thing? I though it was the other way around. To me, it makes more sense to draw the circle of uncertainty around the rocket, not me. I don't really care if the phoen doesn't have a perfect fix for me. I know where I am.

I think the map view is very useful because you can't always walk directly towards the rocket. There could be a lake, dense trees, cliff etc. and it would be nice to see that before you head off.

I don't have any way of knowing if I'm getting data in your app. In the app Kevin wrote, he has a log screen that shows the messages coming in. It would be nice if you had this too for debug purposes.

The circle is drawn automatically with google maps api, I can try to draw the precision circle around the rocket also, this data in in the nmea sentence. Good idea, I take notes.

For the console screen, It's also a good idea, I already wanted to do it but did not..

Thank you very much for your ideas and recommendations, it's appreciated.

 

[kruland]

Ok, got it working. Apparently, I had to import the google-play-api's package and copy the sources into my workspace. Works on Nexus 7.

Gotta say, that looks totally cool. I like the "bing" sounds as well. I think we should try to combine forces on this. I've been working pretty hard on getting the service working correctly. Not very glamorous but necessary. Can you try making your main activity into a fragment?

Kevin

 

[fantasiiio]

Hi, today I launched a rocket and really lost it for the first time since I have my GPS Rocket Locator. I lost it in the woods and couldn't go to it in straight line. Thanks to my Rocket Locator, I easily found my rocket in the woods, it was hanging in a small tree.

I have to says that it was missing the compass feature to be exactly what I want from my rocket locator.
So, I'm coding this feature now, it's almost done.

Frank.

 

[kruland]

That's good news!

Kevin

Hi, today I launched a rocket and really lost it for the first time since I have my GPS Rocket Locator. I lost it in the woods and couldn't go to it in straight line. Thanks to my Rocket Locator, I easily found my rocket in the woods, it was hanging in a small tree.

I have to says that it was missing the compass feature to be exactly what I want from my rocket locator.
So, I'm coding this feature now, it's almost done.

Frank.

 

[fantasiiio]

The compass feature is now functional, with a beeping signal that accelerate when we are in the right direction.
Unfortunately, my svn server crashed, and I have to restart all from zero, I lost my svn history. I didn't lost my code, it was on another computer.
It will be probably available tonight, but these who already downloaded my code, they will have to delete the folder and re-checkout.

 

[bill2654]

Sure would be nice if you four guys would make this simple enough for the average person.

 

[kruland]

Bill,

Hopefully simple will come soon. Do you have Derek's hardware? I can send you an android apk to install - though it's still in development. Drop me your email address in a PM.

Kevin

Sure would be nice if you four guys would make this simple enough for the average person.

 

[fantasiiio]

Sure would be nice if you four guys would make this simple enough for the average person.

If you talk about the software, it will be on google play store soon (couple of days) for download, ready to use.

 

[bill2654]

I have been following this thread since the beginning but I soon realized I had no idea what you guys were talking about. I don't have any hardware but I do have an Android phone. When you get all the bugs worked out will you post info on where to get the hardware and software? I hope these won't be kits that have to be put/soldered together. I cant see putting a bunch of $$ into soldering equipment that I would only use once. I consider myself pretty handy with tools but not so good with small and precise assembly's. I really would like a tracker for a project Im working on but I cant afford $300 to $500. Keep up the good work guys cause this hobby really needs something like this.

 

[Derek]

When you get all the bugs worked out will you post info on where to get the hardware and software?

the hardware Kevin talked about is documented here:

https://www.rocketryforum.com/showt...Track-Open-Source-GPS-Tracker-for-Smartphones

You don't need an expensive soldering station to build it. Just an iron with a fine tip, some solder, tweezers and a magnifying lens of some type. Solder wick won't hurt in case you get carried away with the solder. But you do need to be able to solder small parts.

 

[fantasiiio]

Here is the part needed :
-GPS module $35
-APC220 (wireless communication) $35 (for two), OR two Xbee modules.
-Bluetooh module $10
-5V voltage regulator $5 (for two)
-Batteries $10 (for two)
-Antenna $10 (The original one is L shaped)
-Software: Free

These prices are from cheaper China sellers on ebay.
The connection is fairly simple. Just connect the GPS tx into apc220 rx, and on the receiver connect apc220 tx to blutooth rx.
You also need to connect vcc and ground on all modules with the 5v regulators.
That's all I did.

Frank.

 

[bill2654]

Derek and Frank, are you or anyone else planning to sell these in kit form like Boris does with his Arduino altimeter? I don't know an Amp from an Ohm and I don't know one "module" from the next so how would I know if I was getting the correct parts? There are probably lots of different ebay sellers with similar products, and me not knowing the correct terminology, might be a problem. I hate dealing with Chinese sellers and if I get the wrong part or it's defective, I will be waiting months to get it right.

 

[Derek]

Derek and Frank, are you or anyone else planning to sell these in kit form like Boris does with his Arduino altimeter? I don't know an Amp from an Ohm and I don't know one "module" from the next so how would I know if I was getting the correct parts? There are probably lots of different ebay sellers with similar products, and me not knowing the correct terminology, might be a problem. I hate dealing with Chinese sellers and if I get the wrong part or it's defective, I will be waiting months to get it right.

I don't sell them in kit form. Just the pcbs. You can order the parts just as easily as I can. I include a complete parts list for my boards in the zip files in the thread. just copy and paste them into digikey or mouser's website and hit buy.

edit:

all the parts for my tracker are available from vendors in the us that sell millions of these parts every month (digikey and mouser). you'll get them in a day or two. the batteries and antenna are available from vendors in the us or china. the Chinese vendors take longer (usually about 3 weeks), but the price savings can make it worth it for these two items.

 

[fantasiiio]

Hi, yesterday I wanted to test the range of my rocket locator. It was windy so, I tried it. The rocket goes pretty high and very far. It landed almost 1300 feet far, in a large field with long grass and small trees. Man... I'm a programmer, I don't do sports, it took me 20 minutes to walk to the rocket and another 20 minutes to return. I was exhausted.
But I found it !

In the other hand, the range was on limit. I received a gps signal each 5-6 second and lost the signal 2 times. I finally got a gps signal when the rocket was almost on the ground..
The APC220 is not power enough for a mid-range rocket. The Xbee 900 is probably a better choice to go very far.

But the software itself works very well.
Still some minor features to adjust, like a button to turn off the beeping compass.

 

[accpool]

Derek and fantasiiio are your 2 products compatible and do i need anything else?

 

[accpool]

Derek and Frank, are you or anyone else planning to sell these in kit form like Boris does with his Arduino altimeter? I don't know an Amp from an Ohm and I don't know one "module" from the next so how would I know if I was getting the correct parts? There are probably lots of different ebay sellers with similar products, and me not knowing the correct terminology, might be a problem. I hate dealing with Chinese sellers and if I get the wrong part or it's defective, I will be waiting months to get it right.

if you need help assembling parts i could help you with this.

 

[fantasiiio]

Derek and fantasiiio are your 2 products compatible and do i need anything else?

Yes our 2 software are compatible. Derek and kevin tried my software with their hardware.
The hardware is not less than a standard bluetooth GPS, but wireless. You can plug the GPS module direcly on the bluetooth module and it work well. But in this case, you cannot go farther than 15-20 feet, because the bluetooth range is small.
The GPS send a packet, each second, in NMEA sentence, that is a standard for all GPS modules. So, any GPS module with UART output (gnd, vcc, rx and tx) will work.

 

[Derek]

Derek and fantasiiio are your 2 products compatible and do i need anything else?

yep, this software will just work with your tracker.

Kevin's software is coming along nicely as well. you can build the sw and check it out for yourself.

 

[bdureau]

I was wondering if the transmeter could be replaced by one of the following which are more powerfull
https://www.rfremotech.com/TransimittingModules.html
Some of the could transmit up to 4km