Hi all
According to @Mark Hughes project about HC-12 transceiver
https://www.allaboutcircuits.com/projects/gps-transmission-with-the-hc-12-transmitter/
I thought that it is possible to transmit gps coors (NMEA) from an android device to another android device with HC-12 via a bluetooth module (i.e. HC-06).
What kind of software is needed, to show 1st smartphone's location to the 2nd smartphone in an app such as Google Maps or a similar one (that uses Google Satellite, World Imaginery etc)?
Mark pointed an app called Bluetooth GPS Output (https://play.google.com/store/apps/details?id=com.meowsbox.btgps&hl=en). Did anyone use this app?


Sorry for my english.

 

Hi @GiorgosK,
Depending on whether or not the app utilizes the physical layers of BLE5 and whether or not your phone supports it -- you might be able to skip the HC12s altogether. BLE5 1M Coded has a purported range of 1.5 km -- which is roughly the same range as the HC12 in high-power/low-speed mode. Once technology catches up to the standards, you should be able to transmit phone to phone via BLE5.
For now -- you'll likely have to create two little gateway transceivers that each have a BLE5 and HC12 on them (this article may or may/not help -- https://www.allaboutcircuits.com/pr...om-project-gt-tronics-ble5-module-CC264BNA-S/)

What is your ultimate goal? What problem are you trying to solve? There might be easier ways to do it.

@ericgibbs You might be able to offer advice in this thread.

Thanks!
Mark

P.S. This looks like the companion app that goes on the other phone: https://play.google.com/store/apps/details?id=de.mobilej.btgps

 

Well my goal is to access someone's location on my smartphone (or any device) in an aerial map environment without the use of GSM (i.e. I want to see the position of my mates in a paintball game)
Like a base-rover gnss kit which are communicate via radio-modem (but on this case the base sends gps corrections). I need to send only the location from one unit to the other
As you said (to another member) it can be done with APRS, but I am not familiar with that.

 

@GiorgosK -- What sorts of distances will be involved?

 

@Mark Hughes I think 1,5 km should be enough. But you said it can be extended with an antenna, right? Optimal is a 5km distance, but I do not think that it will be ever needed such a range.
Think about like a 5-6 people walking around in countryside, like a hunting group or a paintball group etc. with not at all or very poor gsm signal.

 

@GiorgosK,
Let's get @ericgibbs thoughts.....I don't think you'll ever see 1.5 km with the default spring-coil antenna on the HC12, or BLE5 1M coded on your smartphone. With a directional (Yagi or log-periodic), perhaps....but those are not practical antennas for your situation.
What country are you located in? And why are you trying to avoid the use of cell-phone networks (lack of availability / high cost?) The reason I ask, is that it might be better to get rid of the HC06/HC12 and upgrade to a more powerful transmitter that will provide you the desired range.
Mark

 

@Mark Hughes
In the areas that I am intersted, there is no cellphone network. Hellas (Greece) has only 3.
I thought a low cost project, similar to the way that garmin astro 320 (dog track collar) or a mid range drone (like dji phantom4) work, might me helpful for me.

More powerful transmitter?


(Sorry for my english)

 

hi G,
As Mark states, 1.5km is over the specified range of the HC12 of 1km.
If you choose a more powerful transmitter, check the permitted power and frequency ranges that are permitted in Greece.
E
@Georacer

 

@ericgibbs
I own promark3 base rover and this is a lisence free radio modem

ftp://ftp.ashtech.com/Spectra-preci...rk 3/Hardware/RadioModem_DS(A4en)19Sept07.pdf

 

hi G,
I cannot open that link, error message.

 

I uploaded the file

 

@GiorgosK,
If you and your team are willing to get a basic Amateur Radio Operator's License, your options really start to open up -- and you can buy off-the-shelf solutions. In America, a basic license is a relatively easy multiple-choice test (no Morse-code requirement).

This product, for example, connects to your phone via Bluetooth and has 1 W output -- it should cover the range you want without much problem.

https://www.ebay.com/itm/AVRT5-APRS...id/112595451716?hash=item1a37363f44:rk:1:pf:0

It works with APRS-droid

https://aprsdroid.org/

Just a note -- I've never used either product -- so I'm not endorsing them -- they are just the first ones to show up in a Google search. I have used APRS and gotten position information from <100 km away.

 

@Mark Hughes
About APRSdroid: Do I have to report my position to the network or I can share it only with my team? And, do I have to see all nearby radio stations or only my team?
Should I spend about 100$ +shipping (x2), without knowing if it will work?

I have used APRS and gotten position information from <100 km away.

What kind of software did you use?

As a land surveyor, APRS could solve many problems (and money) due to lack of GSM signal. Most of us use a public or a private network with a VRS (virtual reference station) as a base, sending us (rover) the appropriate gps corrections. That could be done with APRS. Most VRS do not exceed 50 klm away from rovers.

 

@Mark Hughes
About APRSdroid: Do I have to report my position to the network or I can share it only with my team? And, do I have to see all nearby radio stations or only my team?
Should I spend about 100$ +shipping (x2), without knowing if it will work?




What kind of software did you use?

As a land surveyor, APRS could solve many problems (and money) due to lack of GSM signal. Most of us use a public or a private network with a VRS (virtual reference station) as a base, sending us (rover) the appropriate gps corrections. That could be done with APRS. Most VRS do not exceed 50 klm away from rovers.

Not VRS.
CORS Continuous Operating Reference Station

 

Hi everyone,

Without having figured out the entire solution, I'd like to add a couple of things:

1. In Greece, the "official" permitted license-free RF power is 100mW, including antenna amplification, plus restrictions on duty cycle. However, a lot of market products already violate this, esp. UAV (drone) products.
That said, in an area where not even GSM is available, I highly doubt a 500mW transmitter will hurt anyone.

2. I don't know about Google Maps, but I do know that Google Earth does accept NMEA streams. I don't know how it will handle multiple coordinates, though.

3. If you plan to play in a forest area, I don't believe any ground-based solution in 2.4GHz or 866MHz will work. The attenuation from the leaves will be too high. I'd go for a 433MHz solution, which has better penetration.
If you're talking open fields, then it could be doable.

4. Your Magellan digital radio should be more than powerful enough, but it's quite an expensive solution and you'll likely need a pair for each player, I don't believe it will handle a star topology.
Besides, a star network topology will need a specialized visualization software, since the hardware device at the computer's end wouldn't be able to tell which NMEA stream comes from whom.

In all, it's not a trivial technical problem, because
a) You need to visualize multiple NMEA streams and
b) You need to penetrate forests (please confirm)

A relatively easy solution would be to re-purpose an Ardupilot autopilot kit AND use a mesh of XBee radios to build a mesh network AND use Mission Planner (http://ardupilot.org/planner/docs/mission-planner-overview.html) in swarm mode to display multiple agents.
But I only say this because I'm familiar with this sector. A better solution may very well exist.

 

@Georacer
1. I agree with you
2. Google Earth does accept NMEA streams, but in desktop version. I do not think that it can do it in android version
3. I agree, too.
4. Yes, the cost is too much.

a. In @Mark Hughes project HC-12 can stream NMEA sentences (to arduino).
b. Yes

I thought about your 2nd solution (not exactly building a mesh network). If you are familiar, do you know how and where to start with?

 

I just realized that you want to see the player coordinates in an Android device, so my proposition isn't directly applicable.
Still, it begs the question, what exactly will be your network topology?

Do you want to visualize multiple GPS locations in only one device, or you want all the GPS locations to be accessible in all of the player devices?
This decision will likely change your design.

 

@Georacer
I think "multiple GPS locations (max 5?) in one device" is ok for now.
It is more complicated if we use multiple devices, isn't it?

 

@GiorgosK,
Don't buy anything just yet. Leave the thread open long enough for some people to stumble in here, read the problem description, and offer advice. In most situations, it is better to purchase a ready-made solution than to prototype and build your own.

To Answer your questions from earlier:
1) If you and your own team choose a non-default frequency, your signals will be effectively "isolated" from the rest of the network. I don't know about Greece -- but in the U.S., amateur radio transmissions cannot be encrypted (except for satellite). So it is possible that someone could discover that you are using APRS, buy the necessary equipment, and find your team.
2) At the time, I was using a TNC-Pi (Hardware controller) with a Baofeng HT (radio), and I'm afraid I don't recall the software (likely whatever software the TNC-Pi recommended).

Distances are estimated with a link-budget -- how sensitive the receiver is, how powerful the transmitter is, the antenna used, and the distances & elevations involved all come into play.

@KL7AJ ,
Any thought on how @GiorgosK can track his teammates during paintball without the use of cell-phone network?

 

How does this work?
https://lynqme.com/