Bluetooth GNSS

Connect your Android phone to external Bluetooth GPS, GLONASS, Galileo and BeiDou receivers and use the received location in your android phone via the mock location provider.

Official app is available on Google Play as Bluetooth GNSS.

Build instructions

• Install the the Flutter SDK as per official instructions including the 'Android setup' and make sure that the Android SDK is installed.

• Make sure the flutter sdk version matches that of below:

flutter downgrade v<flutter ver in pubspec.yaml>

• In this folder run: flutter pub get

• If you modify the rust code then update with (first install same ver to match that of flutter_rust_bridge in pubspec.yaml - see https://cjycode.com/flutter_rust_bridge/quickstart) flutter_rust_bridge_codegen generate

• If you don't already have an android signing key, create one as per: https://docs.flutter.dev/deployment/android#create-an-upload-keystore

• Create the file key.properties in parent of this folder and add your keystore information:

  storeFile=/path/to/keystore.jks
  storePassword=*********
  keyAlias=bluetooth_gnss
  keyPassword=**********

• Connect an android phone with adb working adb devices

• Try build and run the app in debug mode: flutter run If all went well, you would see the app now run in your connected phone.

• Try build a release android installer (apk) file: flutter build apk If all went well, it would create the apk file in the folder: build/app/outputs/flutter-apk/app-release.apk

• Develop in Android studio:

  • Open android studio, and choose 'Projects' > 'Open' to this folder (or File > Open... menu) and you can edit the source code then run 'main.dart' from there. This is suitable for editing the dart files in the lib folder.
  • UI changes to main.dart can be seen immediately (hot-reload) on phone but function changes or java/engine part changes won't, you need to 'stop' then 'run' main.dart again for the changes to take effect.
  • Auto-completion of java code (in the android subfolder) and running of the java unit-tests won't work as this Android Studio is run in a 'flutter' project mode. To edit the engine part and run the java unit tests, simply open the 'android' subfolder of this folder in a new Android Studio instance: File > Open ... choose: bluetooth_gnss > android. After Android Studio is ready, then you can try run some tests like browse on the left panel to libecodroidgnss_parse > java > (test) and right click on 'test_nmea_parse' > Run.

• Use the flutter build apk command when you want to build a release apk file.

Initiate connection using external intent

I'm using Tasker to send the intent, but other methods are possible

Configure the task

On the TASKS tab, create a new task (e.g. Connect GPS) and add the action Send Intent. It is configured as follows:

• Action: bluetooth.CONNECT
• Cat: Default
• Mime Type: text/plain
• Data: <empty>
• Extra: <see json string below>
• Package: com.clearevo.bluetooth_gnss
• Class: <empty>
• Target: Broadcast Receiver

json string in Extra field

Add this string without newlines. All values are optional. Note that config is without double quotes

config: {
    "bdaddr": "%bt_address",
    "secure": false,
    "reconnect": true,
    "log_bt_rx": true,
    "disable_ntrip": true,
    "extra": {
        "ntrip_user": "taskeruser",
        "ntrip_mountpoint": "taskermount",
        "ntrip_host": "taskerhost",
        "ntrip_port": "2000",
        "ntrip_pass": "taskerpass"
    }
}

Example

If you only want to override the bluetooth address, you can send this as extra:

config: {bdaddr:"%bt_address"}

If you don't use the BT Connection Event (see below) but the BT Connection state, you have to use the real address of your device:

config: {bdaddr: "00:11:22:33:44:55:66"}

If you want to disable ntrip as well:

config: {bdaddr: "00:11:22:33:44:55:66", disable_ntrip: true}

Configure the event

On the PROFILES tab, you can use a state change or a event. In this example, I'm using the BT Connection event with the following conditions:

• %bt_connected EQ true
• $bt_address EQ 00:11:22:33:44:55:66, the bluetooth address of the GPS receiver

This will trigger the event only when my GPS receiver is connected. You can add multiple devices here, which is why I choose this method: in the action, the variable %bt_address will be available as well and I'll use that to pass to Bluetooth GNSS.

Special thanks

• Thanks to Geoffrey Peck from Australia for his tests, observations and suggestions.
• Thanks to Peter Mousley from Australia for his expert advice, tests, code review, guidance and code contribution.
• Thanks to Auric Goldfinger for his great contribution in developing the auto connect on boot feature and the detailed readme merged into above.
• Thanks to everyone who provided comments/suggestions on the bluetooth_gnss project issues page on github.

Authors

• Kasidit Yusuf
• Auric Goldfinger
• For the most up-to-date list, run git shortlog -sne in this git repo.

Copyright and License

Copyright (C) 2019 Kasidit Yusuf and all respective project source code contributors.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.