Originally Posted by iskess

I was just hoping to get a better feel for the project and how it all fits together and functions. If a video is too time intensive, how about more photos showing close ups of the finished product. I would also like to see what the Rx side looks like in its box.
I have the soldering skills to handle a project like this, but I haven't done much arduino building. Perhaps I should let someone else do first.
I am looking forward to the foxhunting functionality to be added.


To save weight, can I share the GPS with my autopilot? I would use your PCB to power the GPS since it designed to remain powered after impact. The open space where the GPS usually could hold my battery.

Here are a few pictures of the assembled Tx. You will notice quite a few things:

• it's a still being used as a development platform, so I left long wires and it's not heat-shrink covered yet. The final version will be wrapped in heat-shrink for added strength
• I used an abused Arduino 3.3V module on the prototype. That module had a ripped out trace, and was replaced with a purple wire
• This was V1.1 of the board, and the smd pads for the LED and resistors are too small for hand soldering, so you will see poor soldering
• I'm using a temporary helix antenna instead of the antenna wire that I will use in the final

As for the Rx, you wouldn't want to look at it now it's basically a jumble of Dupont wires attached to modules with pin headers, which I use for generic development. The wiring of the Rx is pretty simple (3.3V and gnd to all modules, plus 5 wires to the 5110, and another 5 to the LoRa module), plus whatever header you want to use for the FTDI port. Once I'm done adding the Bluetooth module, I'll share a schematic and possibly more pictures.

As for sharing the GPS module, that would not be possible. The way I use the GPS is not compatible with how the FC uses it, plus sharing a single serial communication would be a clear recipe for disaster. A GPS module is <$9, there is really no reason to change how it works. As a matter of fact, you want the tracker to be a standalone unit, since you can easily move between models and use it for any other purpose (tracking your kids on a bicycle, for example).

The additional weigh is a non-issue for anything bigger than a 150mm quad, and on smaller units you are better off with a loud beeper, since those can't fly that far anyway . If you have a quad that can fly far but can't handle the weight, a radio-only tracker would probably work better for you (and be super-light)

I just added information on how to connect a Bluetooth module and use an Android app to help locate your model https://www.rcgroups.com/forums/show...07&postcount=6

I also updated the receiver code, to handle the Bluetooth module and fixed a minor NMEA compatibility issue

Originally Posted by robca

..... I’m using it to send NMEA data to GPS Rocket Locator, a great Android app that does exactly what we need https://play.google.com/store/apps/d....rocketlocator. You can find the description, screenshots and a link to a donate page here: http://rocketlocator.com/ (thanks to user gpsklaus for the initial suggestion, and thanks to Francois for developing such a great app and answering my questions). With this app, you can map your location, the location of your model, and easily find it (you can build a version of the receiver without the 5110 and just use this app, but the LCD is pretty helpful)........

OK about also using the Android APP "Rocket Locator". One weak point with it could be the always actually needed Internet contact required for loading maps. So i did look for alternative solutions and also did test with using two other APP's. Both also can be used with using pre installed offline maps, but unfortunately in both cases also different input data formats than GGA or RMC are used.
One of it is "Locus Map Pro". For also showing external position data, this APP will accept NMEA waypoint sentences type "WPL".
The second one is called "W2APRS". There are two versions, where one of it also will accept OSM maps. In this case input signal must be in APRS format.
Based on Stuarts work i did make different LoRa decoder versions with providing serial output signals as required for those APP's and there were no special problems. More can be seen after watching my page on this subject ( Page is in German, but at least there is a button for direct translation into English ): http://www.kh-gps.de/lora.htm

Can we expect on the schematic ? ..

Originally Posted by gpsklaus

OK about also using the Android APP "Rocket Locator". One weak point with it could be the always actually needed Internet contact required for loading maps. So i did look for alternative solutions and also did test with using two other APP's. Both also can be used with using pre installed offline maps, but unfortunately in both cases also different input data formats than GGA or RMC are used.
One of it is "Locus Map Pro". For also showing external position data, this APP will accept NMEA waypoint sentences type "WPL".
The second one is called "W2APRS". There are two versions, were one of it also will accept OSM maps. In this case input signal must be in APRS format.
Based on Stuarts work i did make different LoRa decoder versions with providing serial output signals as required for those APP's and there were no special problems. More can be seen after watching my page on this subject ( Page is in German, but at least there is a button for direct translation into English ): http://www.kh-gps.de/lora.htm

Thanks for the suggestions, will look at those... I'll also ping the Rocket GPS author and see if he knows of a way to cache maps...

Originally Posted by Rumcajs

Can we expect on the schematic ? ..

Do you mean the receiver schematics? I'm not sure when I'll find the time, but the Arduino sketch clearly lists all the pins to connect, including (in the latest version) the Bluetooth module:

// Arduino pins for LoRa DRF1278F
// Arduino pin -> DRF1278F pin, Function
// D6 -> 1 RESET
// D7 -> 13 NSS
// D11 -> 12 MOSI
// D12 -> 11 MISO
// D13 -> 10 SCK

// Arduino pins for 5110 LCD
// Arduino pin -> 5110 module
// D8 -> 5 D/C
// D9 -> 4 RESET
// D10 -> 3 SCE
// D11 -> 6 DN (MOSI)
// D13 -> 7 SCLK
// LED backlight connected to VCC with a resistor

// Arduino pins for HC-06 Bluetooth module
// D2 SoftSerial Rx to HC-06 Tx
// D3 SoftSerial Tx to HC-06 Rx

Since the RFM98 and Dorji DRF1278F have the same pins (just a different physical layout), you can use either a RFM98 or DRF1278F on the receiver

Oops! .. I want to make your own pcb, because this on OSHPark provides for solder GPS, and not even looked into the code

Originally Posted by Rumcajs

Oops! .. I want to make your own pcb, because this on OSHPark provides for solder GPS, and not even looked into the code

My bad for not making it clear but, yeah, it's all there, and equivalent to a schematic, since I list each connection for each module

Have you considered the transmission of GPS coordinates via morse code? We can use the standard 3 tone fox hunting signal every few seconds, then once a minute it can transmit the GPS lat/long. Maybe after the first hour, the morse code is only sent every 5 mins to save battery?
This will eliminate the need for a specialized receiver, and and walkie talkie could be used. I imagine not loosing a model for a couple years, then it happens one day and I discover my receive model is not working, or left at home, etc. I can run to a local store and buy a walkie. I can also have numerous other people assisting with the hunt. Many apps decode morse code tones to make it easier.

I have, but it's not an interesting problem to solve for me, I'm afraid... There are already solutions (you can find them with an online search) implementing Morse code (some developed by srnet).

These days everyone has a smartphone, and I like the ability to use the tracker both as a telemetry device (you can send any data from the drone), and as a lost model locator. The way I envision using it, the receiver/smartphone is being used every flight, as an extra telemetry device. It's also much more generic, since it can be used to locate anything, not just lost models. Kids out on a boat? you know where they are...

So, good idea, but not something I plan to do... the code to generate FM tones with RFM22 and other modules is widely available (no need to use a more expensive LoRa module), and you can use my code to parse the GPS location...

Sadly I find myself a slave to the Apple iPhone, so I can not benefit from the Bluetooth option.

There are always the super-cheap Android tablets to be used just for this even without data, you can connect them to the iPhone thru Wifi and use them just as a mapping device

Yes, but I don't plan on using this beacon unless I have a crash. So it will just sit in the flight box with a dead battery. If it worked with my phone, I definitely see the benefit. Good point about using it to track kids or pets. One more reason to switch to Android!

Fantastic project with several links very cool !!!!

Thanks for this share !!!!!

Hi RobCa,
I'm waiting to receive all components to build up your project.
I'll use it for a different task : fishing buoys (four) for now ,
Looking into the tx software I've noticed two things:
in bool SetUBX()
you states : // set UBX protocol-only on PORT1
but I think you do not set ubx protocol only , am I correct ?
second point I cannot get the gps module (ublox M6) to send the date-time
values with the command GPS.println("$PUBX,04*37")
any suggestion ?
congrats for the beatiful pj
Mauro