Showing GPS latitude and longitude, and sending it to a phone through bluetooth

The goal of my project is to recieve multiple data from sensors and into a arduino uno (GT016) and then into a bluetooth module (Pmod BT2) which sends the data into a phone that has the app which I made using ai2.appinventor.

But for a test I only used a GPS module (Position GPS 746), and tried to display the latitude and longitude on my app. I also used the Adafruit GPS library, specifically the GPS_SoftwareSerial_Parsing file to recieve data.

#include <Adafruit_GPS.h>
#include <SoftwareSerial.h>

// Connect the GPS Power pin to 5V
// Connect the GPS Ground pin to ground
// Connect the GPS TX (transmit) pin to Digital 8
// Connect the GPS RX (receive) pin to Digital 7

// you can change the pin numbers to match your wiring:
SoftwareSerial mySerial(8, 7);
Adafruit_GPS GPS(&mySerial);

// Set GPSECHO to 'false' to turn off echoing the GPS data to the Serial console
// Set to 'true' if you want to debug and listen to the raw GPS sentences
#define GPSECHO  false

void setup()

  // connect at 115200 so we can read the GPS fast enough and echo without dropping chars
  // also spit it out
  Serial.println("Adafruit GPS library basic parsing test!");

  // 9600 NMEA is the default baud rate for Adafruit MTK GPS's- some use 4800

  // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
  // uncomment this line to turn on only the "minimum recommended" data
  // For parsing data, we don't suggest using anything but either RMC only or RMC+GGA since
  // the parser doesn't care about other sentences at this time

  // Set the update rate
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);   // 1 Hz update rate
  // For the parsing code to work nicely and have time to sort thru the data, and
  // print it out we don't suggest using anything higher than 1 Hz

  // Request updates on antenna status, comment out to keep quiet

  // Ask for firmware version

uint32_t timer = millis();
void loop()                     // run over and over again
  char c =;
  // if you want to debug, this is a good time to do it!
  if ((c) && (GPSECHO))

  // if a sentence is received, we can check the checksum, parse it...
  if (GPS.newNMEAreceived()) {
    // a tricky thing here is if we print the NMEA sentence, or data
    // we end up not listening and catching other sentences!
    // so be very wary if using OUTPUT_ALLDATA and trytng to print out data
    //Serial.println(GPS.lastNMEA());   // this also sets the newNMEAreceived() flag to false

    if (!GPS.parse(GPS.lastNMEA()))   // this also sets the newNMEAreceived() flag to false
      return;  // we can fail to parse a sentence in which case we should just wait for another

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) {
    timer = millis(); // reset the timer

    Serial.print("\nTime: ");
    if (GPS.hour < 10) { Serial.print('0'); }
    Serial.print(GPS.hour, DEC); Serial.print(':');
    if (GPS.minute < 10) { Serial.print('0'); }
    Serial.print(GPS.minute, DEC); Serial.print(':');
    if (GPS.seconds < 10) { Serial.print('0'); }
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    if (GPS.milliseconds < 10) {
    } else if (GPS.milliseconds > 9 && GPS.milliseconds < 100) {
    Serial.print("Date: ");
    Serial.print(, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
    if (!GPS.fix) {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 4); Serial.print(;
      Serial.print(", ");
      Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);

      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);

With the serial moniter (values are zero because I was inside a building)

My question is how do I get the values I want from the arduino and display it on a bluetooth app?

Below is what I have done so far, but I tried different methods and couldn't advance.
Please advice

Hi arno.

You can certainly do all that you want to do.

It is essential to have some tools.

You must have a way of viewing the raw NMEA sentences coming from the GPS module. Whenever I have trouble with my GPS app I go back to viewing the raw NMEA sentences.

You need a serial bluetooth app on your phone. There are a few available. This will display the data coming from your GPS/Arduino/Bluetooth device easily and reliably.

Your app could also show the raw NMEA sentences or the individual fields like lat & long.

I don't know the Adafruit GPS library so cannot help you there. I use the TinyGPS++ library.

My GPS app that I built with MIT App Inventor is now at 1200 blocks.

You can do anything you want, but you need to master each element. The effort is worthwhile.


Looks like if you set GPSECHO to TRUE then the sketch will send the raw sentences to your serial output.

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