GPS Module with Integrated Antenna and TTL SERIAL Output – An Overview

This is a third generation POT (Patch Antenna On Top) GPS module. This POT GPS receiver providing a solution that high position and speed accuracy performances as well as high sensitivity and tracking capabilities in urban conditions & provides standard NMEA0183 strings in “raw” mode for any microcontroller.
The GPS module has to be powered with 3.3V. It is 3v3 powered , level converter( 3v3-5v) may be required for interfacing with 5V microcontroller.The GPS chipsets inside the module are designed by MediaTek Inc., which is the world’s leading digital media solution provider and lfab-less IC company in Taiwan. The module can support up to 51 channels. The GPS solution enables small form factor devices. They deliver major advancements in GPS performances, accuracy, integration, computing power and flexibility. They are designed to simplify the embedded system integration process.

To determine the location of the GPS satellites two types of data are required by the GPS receiver: the almanac and the ephemeris. This data is continuously transmitted by the GPS satellites and your GPS receiver collects and stores this data.The data received is just ASCII text and varies in precision. Every sentence begins with a ‘$’ sign, has about 80 characters and ends up with a carriage return/line feed sequence. Sentences are mostly framed in single lines (may run over to multiple lines sometimes) and the data items in each sentence are separated by commas.As the module provides current time, date, latitude, longitude, speed, altitude and travel direction / heading among other data, so it can be used in a host of applications, including navigation, tracking systems, fleet management, mapping and robotics.

Features:

TTL asynchronous serial interface
Data output Baud rate: 9600 bps(Default)
Single 3.3 VDC supply @ 55 mA (typical)
Standard NMEA0183 output format
Standard 8-pin header interface (.100″ spacing).
Based on MediaTek Single Chip Architecture.
Dimension: 26mm x 26mm x 11.7mm
Patch Antenna Size: 25mm x 25mm x 4mm
Low Power Consumption: 55mA @ acquisition, 40mA @ tracking
L1 Frequency, C/A code, 51-channel
High Sensitivity: Up to -158 dBm tracking, superior urban performances1
Position Accuracy: < 3m CEP (50%) without SA (horizontal)
Cold Start is Under 36 seconds (Typical)
Warm Start is Under 34 seconds (Typical)
Hot Start is Under 1 second (Typical)
Max. Update Rate : 5Hz (Default: 1 Hz)
RoHS Compliant

Specification:

How to Test:

1. Test your GPS Module with PC

Here a sample test is shown using RhydoLabz USB to Serial Converter (5V/3V3). When USB cable is connected to the converter, “PWR LED”(Blue) on the top of converter module and “PWR LED”(Blue) on the top of GPS module glows , which shows the power indication.
The connection details of GPS module with USB to Serial Converter (5V/3V3) and interfacing requirements of GPS Receiver to PC are shown below.
Many embedded devices communicate over the serial port connection as most modern computers lack a hardware serial port USB adaptors are used to convert USB data to standard serial port data and vice versa.
For a quick tutorial on USB to Serial Converter (5V/3V3) and connection details please Go through the link.
Once you are done with all these procedures , Choose the appropriate COM port that got assigned to the USB in your system by looking into the device manager like as shown below. In this figure you can see USB serial COM5 got selected.
Here sample test was done using GPRMC header . GPRMC tells the latitude, longitude, speed, time and date. The details of GPRMC message is shown below.
When GPS receiver get the weak signal,then the received GPS data is as shown in the figure. The alphabet ‘V’ on the GPRMC header indicate a weak signal from the satellite, which means by measuring distance from four satellites four spheres are drawn from earth to each satellite. Those spheres only intersect at only one earth point (your location). If there were only 3 satellites, there is more then one place the spheres intersect which is why the system needs that forth satellite so a bad calculation can not be made. The GPS receiver needs 4 satellites to work out your position in 3-dimensions.
When the GPS receiver gets stronger signal from satellite,the GPS data received is as shown in the figure.The alphabet ‘A’ on the GPRMC header indicate the strong signal from the satellite.

2. Test your GPS Module with rhydoLABZ Tracking Software

With the help of Hyper terminal or any other terminal software, you will only be able to see the full NMEA protocol coming in ASCII format and rhydoLABZ tracking software plot your location with the help of GOOGLE map.For using rhydoLABZ software you need to have net connectivity.Here one sample test is shown using RhydoLabz USB to Serial Converter (5V/3V3).
Install the rhydoLABZ Tracking Software (Windows) in your PC shown below.
Open rhydoLABZ Tracking software ,select appropriate COM port from “Select Comport “. The Latitude and Longitude details of the device will be shown in the rhydoLABZ Tracking software,you can get the map view of your location by simply clicking “plot”.

3. Test your GPS Module with Arduino

While interfacing GPS Module with Antenna (TTL SERIAL) with Arduino, the data from GPS is available at TXD pin of the module which is connected to RXD pin of the Arduino board, connection diagram is shown below ( This circuit is not recommended for application, you should have level shifter between controller and GPS module for application purposes).
Testing with Arduino board, sample program is shown below

/**************************************************************************************
  Program to read GPS data and print data to serial monitor.
  BOARD   : Arduino Duemilanove
**************************************************************************************/

  int Gpsdata;             // for incoming serial data
  unsigned int finish =0;  // indicate end of message
  unsigned int pos_cnt=0;  // position counter
  unsigned int lat_cnt=0;  // latitude data counter
  unsigned int log_cnt=0;  // longitude data counter
  unsigned int flg    =0;  // GPS flag
  unsigned int com_cnt=0;  // comma counter
  char lat[20];            // latitude array
  char lg[20];             // longitude array

   void Receive_GPS_Data();

/**************************************************************************************
  Function    : setup()
  Description : Use it to initialize variables, pin modes, start using libraries, etc.
                The setup function will only run once, after each power up or reset
                of the Arduino board.
**************************************************************************************/
  void setup()
  {
    Serial.begin(9600);   // opens serial port, sets data rate to 9600 bps
  }

/************************************************************************************
  Function    : loop()
  Description : loops consecutively, allowing your program to change and respond.
                Use it to actively control the Arduino board.
************************************************************************************/
  void loop()
  {
      Receive_GPS_Data();              
      Serial.print("Latitude  : ");
      Serial.println(lat);
      Serial.print("Longitude : ");
      Serial.println(lg);
      finish = 0;pos_cnt = 0;

  }
/************************************************************************************
  Function    : Receive_GPS_Data()
  Description : finding Latitudse and longitude from GPRMC message

************************************************************************************/
  void Receive_GPS_Data()
  {
    while(finish==0){
      while(Serial.available()>0){         // Check GPS data
        Gpsdata = Serial.read();
        flg = 1;
       if( Gpsdata=='$' && pos_cnt == 0)   // finding GPRMC header
         pos_cnt=1;
       if( Gpsdata=='G' && pos_cnt == 1)
         pos_cnt=2;
       if( Gpsdata=='P' && pos_cnt == 2)
         pos_cnt=3;
       if( Gpsdata=='R' && pos_cnt == 3)
         pos_cnt=4;
       if( Gpsdata=='M' && pos_cnt == 4)
         pos_cnt=5;
       if( Gpsdata=='C' && pos_cnt==5 )
         pos_cnt=6;
       if(pos_cnt==6 &&  Gpsdata ==','){   // count commas in message
         com_cnt++;
         flg=0;
       }

       if(com_cnt==3 && flg==1){
        lat[lat_cnt++] =  Gpsdata;         // latitude
        flg=0;
       }

       if(com_cnt==5 && flg==1){
         lg[log_cnt++] =  Gpsdata;         // Longitude
         flg=0;
       }

       if( Gpsdata == '*' && com_cnt >= 5){
         com_cnt = 0;                      // end of GPRMC message
         lat_cnt = 0;
         log_cnt = 0;
         flg     = 0;
         finish  = 1;

      }
    }
}
}

/**************************************************************************************

Program to read GPS data and print data to serial monitor.

BOARD : Arduino Duemilanove

**************************************************************************************/

int Gpsdata; // for incoming serial data

unsigned int finish =0; // indicate end of message

unsigned int pos_cnt=0; // position counter

unsigned int lat_cnt=0; // latitude data counter

unsigned int log_cnt=0; // longitude data counter

unsigned int flg =0; // GPS flag

unsigned int com_cnt=0; // comma counter

char lat[20]; // latitude array

char lg[20]; // longitude array

void Receive_GPS_Data();

/**************************************************************************************

Function : setup()

Description : Use it to initialize variables, pin modes, start using libraries, etc.

The setup function will only run once, after each power up or reset

of the Arduino board.

**************************************************************************************/

void setup()

{

Serial.begin(9600); // opens serial port, sets data rate to 9600 bps

}

/************************************************************************************

Function : loop()

Description : loops consecutively, allowing your program to change and respond.

Use it to actively control the Arduino board.

************************************************************************************/

void loop()

{

Receive_GPS_Data();

Serial.print("Latitude : ");

Serial.println(lat);

Serial.print("Longitude : ");

Serial.println(lg);

finish = 0;pos_cnt = 0;

}

/************************************************************************************

Function : Receive_GPS_Data()

Description : finding Latitudse and longitude from GPRMC message

************************************************************************************/

void Receive_GPS_Data()

{

while(finish==0){

while(Serial.available()>0){ // Check GPS data

Gpsdata = Serial.read();

flg = 1;

if( Gpsdata=='$' && pos_cnt == 0) // finding GPRMC header

pos_cnt=1;

if( Gpsdata=='G' && pos_cnt == 1)

pos_cnt=2;

if( Gpsdata=='P' && pos_cnt == 2)

pos_cnt=3;

if( Gpsdata=='R' && pos_cnt == 3)

pos_cnt=4;

if( Gpsdata=='M' && pos_cnt == 4)

pos_cnt=5;

if( Gpsdata=='C' && pos_cnt==5 )

pos_cnt=6;

if(pos_cnt==6 && Gpsdata ==','){ // count commas in message

com_cnt++;

flg=0;

}

if(com_cnt==3 && flg==1){

lat[lat_cnt++] = Gpsdata; // latitude

flg=0;

}

if(com_cnt==5 && flg==1){

lg[log_cnt++] = Gpsdata; // Longitude

flg=0;

}

if( Gpsdata == '*' && com_cnt >= 5){

com_cnt = 0; // end of GPRMC message

lat_cnt = 0;

log_cnt = 0;

flg = 0;

finish = 1;

}

When Arduino board receives GPS data,the data on serial monitor is shown below.

4. Test your GPS Module with PIC16F877A

When interfacingGPS Module with Antenna (TTL SERIAL) with PIC16F877A microcontroller, The TXD pin of the GPS TTL is connected to RXD pin of the microcontroller,connection diagram is shown below ( This circuit is not recommended for application, you should have level shifter between controller and GPS module for application purposes).

Testing GPS Module with PIC16F877A, sample program is shown below.

/*******************************************************************************************
Microcontroller -- PIC 16 F877A - 40-pin-8-bit.                            
Clock Frequency is 20 MHz -- Period in 200 Nano second
baudrate-9600.Only the output message – $GPRMC (Recommended minimum specific
GNSS data) is read. The latitude and Longitude value is displayed in the Serial
monitor.      
*******************************************************************************************/

#include<pic.h>

/*******************************************************************************************
                               GLOBAL VARIABLES
*******************************************************************************************/

unsigned char Gpsdata;             // for incoming serial data
unsigned int finish =0;            // indicate end of message
unsigned int pos_cnt=0;            // position counter
unsigned int lat_cnt=0;            // latitude data counter
unsigned int log_cnt=0;            // longitude data counter
unsigned int flg    =0;            // GPS flag
unsigned int com_cnt=0;            // comma counter
unsigned char lat[20];             // latitude array
unsigned char lg[20];              // longitude array

/*******************************************************************************************  
                           FUNCTION DEFINITIONS
*******************************************************************************************/

void UART_Initilization();
void UART_String(const unsigned char *dat);

void main()
{
TRISC = 0X80;
UART_Initilization();             // uart Initialization
GIE  = 1;                         // Globel interrupt enable bit
PEIE = 1;                         // Peripheral interrupt enable bit
while(1){
  while(finish!=1);
   UART_String("Latitude  : ");    // printing GPS data to serial monitor
   UART_String(lat);
   UART_String("\r\n");
   UART_String("Longitude : ");
   UART_String(lg);
   UART_String("\r\n");
   finish = 0;
   pos_cnt = 0;
}
}

/*******************************************************************************************
Function    : interrupt ISR()
Description : interrupt service              
*******************************************************************************************/
void interrupt ISR()
{
    if(RCIF){
      RCIF = 0;
      Gpsdata = RCREG;
      flg = 1;
      if(finish == 0){
       if( Gpsdata=='$' && pos_cnt == 0)  // finding GPRMC header
         pos_cnt=1;
       if( Gpsdata=='G' && pos_cnt == 1)
         pos_cnt=2;
       if( Gpsdata=='P' && pos_cnt == 2)
         pos_cnt=3;
       if( Gpsdata=='R' && pos_cnt == 3)
         pos_cnt=4;
       if( Gpsdata=='M' && pos_cnt == 4)
         pos_cnt=5;
       if(Gpsdata=='C'  &&  pos_cnt == 5 )
         pos_cnt=6;
       if(pos_cnt==6    &&  Gpsdata ==','){  // count commas in message
         com_cnt++;
         flg=0;
       }

       if(com_cnt==3 && flg==1){
        lat[lat_cnt++] =  Gpsdata;        // latitude
        flg=0;
       }

       if(com_cnt==5 && flg==1){
         lg[log_cnt++] =  Gpsdata;        // longitude
         flg=0;
       }

       if( Gpsdata == '*' && com_cnt >= 5 && flg == 1){
         lat[lat_cnt] ='\0';             // end of GPRMC message
         lg[log_cnt]  = '\0';
         lat_cnt = 0;
         log_cnt = 0;
         flg     = 0;
         finish  = 1;
         com_cnt = 0;

      }
     }
    }
}

/*******************************************************************************************
Function    : USART_Initilization
Description : uart basic initilizatin                
*******************************************************************************************/
void UART_Initilization()
{
  TXEN   = 1;
  SYNC   = 0;
  BRGH   = 1;
  SPBRG  = 0X81;
  SPEN   = 1;
  CREN   = 1;
  RCIE   = 1;
  RCIF   = 0;
}

/*******************************************************************************************
Function    : USART_String
Description : transmiting string of datas
*******************************************************************************************/
void UART_String(const unsigned char *dat)
{
    while(*dat!='\0'){
    TXREG = *dat;
    while(TRMT!=1);
      dat++;
  }
}

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/*******************************************************************************************

Microcontroller -- PIC 16 F877A - 40-pin-8-bit.

Clock Frequency is 20 MHz -- Period in 200 Nano second

baudrate-9600.Only the output message – $GPRMC (Recommended minimum specific

GNSS data) is read. The latitude and Longitude value is displayed in the Serial

monitor.

*******************************************************************************************/

#include<pic.h>

/*******************************************************************************************

GLOBAL VARIABLES

*******************************************************************************************/

unsigned char Gpsdata; // for incoming serial data

unsigned int finish =0; // indicate end of message

unsigned int pos_cnt=0; // position counter

unsigned int lat_cnt=0; // latitude data counter

unsigned int log_cnt=0; // longitude data counter

unsigned int flg =0; // GPS flag

unsigned int com_cnt=0; // comma counter

unsigned char lat[20]; // latitude array

unsigned char lg[20]; // longitude array

/*******************************************************************************************

FUNCTION DEFINITIONS

*******************************************************************************************/

void UART_Initilization();

void UART_String(const unsigned char *dat);

void main()

{

TRISC = 0X80;

UART_Initilization(); // uart Initialization

GIE = 1; // Globel interrupt enable bit

PEIE = 1; // Peripheral interrupt enable bit

while(1){

while(finish!=1);

UART_String("Latitude : "); // printing GPS data to serial monitor

UART_String(lat);

UART_String("\r\n");

UART_String("Longitude : ");

UART_String(lg);

UART_String("\r\n");

finish = 0;

pos_cnt = 0;

}

/*******************************************************************************************

Function : interrupt ISR()

Description : interrupt service

*******************************************************************************************/

void interrupt ISR()

{

if(RCIF){

RCIF = 0;

Gpsdata = RCREG;

flg = 1;

if(finish == 0){

if( Gpsdata=='$' && pos_cnt == 0) // finding GPRMC header

pos_cnt=1;

if( Gpsdata=='G' && pos_cnt == 1)

pos_cnt=2;

if( Gpsdata=='P' && pos_cnt == 2)

pos_cnt=3;

if( Gpsdata=='R' && pos_cnt == 3)

pos_cnt=4;

if( Gpsdata=='M' && pos_cnt == 4)

pos_cnt=5;

if(Gpsdata=='C' && pos_cnt == 5 )

pos_cnt=6;

if(pos_cnt==6 && Gpsdata ==','){ // count commas in message

com_cnt++;

flg=0;

}

if(com_cnt==3 && flg==1){

lat[lat_cnt++] = Gpsdata; // latitude

flg=0;

}

if(com_cnt==5 && flg==1){

lg[log_cnt++] = Gpsdata; // longitude

flg=0;

}

if( Gpsdata == '*' && com_cnt >= 5 && flg == 1){

lat[lat_cnt] ='\0'; // end of GPRMC message

lg[log_cnt] = '\0';

lat_cnt = 0;

log_cnt = 0;

flg = 0;

finish = 1;

com_cnt = 0;

}

/*******************************************************************************************

Function : USART_Initilization

Description : uart basic initilizatin

*******************************************************************************************/

void UART_Initilization()

{

TXEN = 1;

SYNC = 0;

BRGH = 1;

SPBRG = 0X81;

SPEN = 1;

CREN = 1;

RCIE = 1;

RCIF = 0;

}

/*******************************************************************************************

Function : USART_String

Description : transmiting string of datas

*******************************************************************************************/

void UART_String(const unsigned char *dat)

{

while(*dat!='\0'){

TXREG = *dat;

while(TRMT!=1);

dat++;

}

When PIC16F877A microcontroller receive GPS data,the datas are displayed on serial monitor is as shown below.

Resources:User Manual
Mini GPS Tool
rhydoLABZ Tracking Software (Windows)

How to Buy:
Click here to buy GPS Module with Antenna (TTL SERIAL).
Click here to buy RhydoLabz USB to Serial Converter (5V/3V3).

Support:Please share your ideas with us, visit our forum for discussion

Frequently Asked Questions(FAQ):Q.What is NMEA0183?
Ans.NMEA0183, or NMEA for short, stands for National Marine Electronics Association, a US standards committee that defines data message structure, contents and protocols to allow the GPS receiver to communicate with other pieces of electronic equipment. NMEA 0183 is a standard data communication protocol used by GPS receivers.

Q. Where do we mount GPS?
Ans. GPS data available around the world. The GPS receiver will need to have a clear View of sky so that the GPS receiver can triangulate at least three satellites. We may find problem receiving signals in indoor area. The GPS signal may blocked by metal, deep forest, mountains etc.

Q.Do we need net connection to work GPS GPS Module with Antenna (TTL SERIAL) with rhydoLABZ Software.
Ans. Yes we need net connection to work with rhydoLabz Software.

Q. Do we need net connection to work GPS?
Ans. No. we don’t need internet connection for GPS data reception.

Q. Does GPS Module with Antenna (TTL SERIAL) need external antenna?
Ans. No, the module is made with inbuilt antenna.

Q.What is Working voltage of GPS Module with Antenna (TTL SERIAL)
Ans. Working voltage of GPS Module with Antenna (TTL SERIAL) is 3.3V

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