Make BLE beacon to transmit GPS coordinates:

• GPS coordinates should be given to the beacon via command from PC
• Bluetooth beacon should have a distinctive Bluetooth device name
• GPS coordinates should be transmitted as advertising data

Solution consists of firmware for NRF52 and two PC applications (nmeaSender and bleReceiver).

It receives NMEA GPRMC messages via UART and parses them. After parsing, firmware updates advertising data with new latitude and longitude.

Port settings: 115200, 8bit, no parity, no flow. NMEA string example:

$GPRMC,094236.013,A,5926.669,N,02444.875,E,060.4,203.3,210719,000.0,W*73
$GPRMC,094240.013,A,5926.547,N,02444.962,E,083.4,227.0,210719,000.0,W*72

<CR><LF> ends the message.

02 01 04= First element with flags

0B = length of "MANUFACTURER_SPECIFIC_DATA"

FF = indicates "MANUFACTURER_SPECIFIC_DATA"

FF FF = Company identifier

00 00 00 00 00 00 00 00 = 4 bytes of latitude and 4bytes of longitude

08 09 74 72 61 63 6B 65 72 D2 = Device short name "tracker"

App reads line by line NMEA data from file and sends to serial port with period 1 sec.

./nmeaSender/nmeaSender /dev/ttyACM0 nmeaSender/sample.nmea

Tool for generating GPS logs in NMEA format: NMEA Generator

App receives BLE advertising packets, parse and draw points on the map. It uses Bluez HCI so it requires root privileges to run.

sudo ./bleReceiver/bleReceiver 

1. Cross-platform IDE for embedded systems: Segger Embedded Studio. After installation open and add nRF CPU Support Package via Tools->Package Manager

2. All-in-one debugging solution: J-Link / J-Trace Downloads

3. Software development kit for the nRF52 SoC: nRF5 SDK ver 15.3059 ac345. Download and extract content to firmware/nRF5_SDK folder

4. Libraries to compile PC utils:

sudo apt install libbluetooth-dev 

And Qt 5.12 framework

1. nmeaSender

cd nmeaSender
qmake
make

2. firmware Open firmware/beacon.emProject in Segger Embedded Studio, build and flash.

3. bleReceiver

cd bleReceiver
qmake
make