Darren Ulrich / GPSISR

A GPS serial interrupt service routine that has an on the fly nmea parser. Works with a STM32F411RE and a Adafruit GPS logger.

Dependents:   Bicycl_Computer_NUCLEO-F411RE Bicycl_Computer_NUCLEO-L476RG

Fork of GPS by Simon Ford

main.cpp

#include "mbed.h"
#include "GPSISR.h"

#define PIN_RX_GPS      PA_12 //GPS Shield RX pin
#define PIN_TX_GPS      PA_11 //GPS Shield TX pin
Serial pc(USBTX, USBRX);

// Set up serial interrupe service handler for gps characters.
GPS MyGPS(PIN_TX_GPS,PIN_RX_GPS, 9600);
int main()
{
    while (1) {
	if (MyGPS.dataready()) {
					MyGPS.read();
					pc.printf("NMEA has valid data");
					pc.printf("Sats : %d \n", MyGPS.buffer.satellites);
					pc.printf("%d-%d-%d\n", MyGPS.buffer.month, MyGPS.buffer.day, MyGPS.buffer.year);
					pc.printf("%d:%d:%d\n", MyGPS.buffer.hours, MyGPS.buffer.minutes, MyGPS.buffer.seconds);
	}
	else {
                pc.printf("NMEA has no valid data");
	}   
   }  
}

GPSISR.cpp

Committer:
trevieze
Date:
2017-02-17
Revision:
3:e64b8be9ce92
Parent:
2:dbc6c0789611
Child:
4:7240a18102a6

File content as of revision 3:e64b8be9ce92:

/* mbed EM-406 GPS Module Library
 * Copyright (c) 2008-2010, sford
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 
#include <string> 
#include "nmea.h"
#include "GPSISR.h"

NMEA nmea; //parse GPS Sentence.

GPS::GPS(PinName tx, PinName rx, int Baud) : _gps(tx, rx) {
    _gps.baud(Baud);
    _gps.attach(this,&GPS::Rx_interrupt, Serial::RxIrq);
    
    printf("Interrupt Attached");
}

void GPS::getline() {
    while(_gps.getc() != '$');    // wait for the start of a line
    for(int i=0; i<256; i++) {
        msg[i] = _gps.getc();
        if(msg[i] == '\r') {
            msg[i] = 0;
            return;
        }
    }
    error("Overflowed message limit");
    return;
}

// Interupt Routine to read in data from serial port
void GPS::Rx_interrupt(void) {
    interrupt = 1;
    rx_in = _gps.getc();
    nmea.fusedata(rx_in);
    interrupt = 0;
    return;
}
 bool GPS::dataready(void){
 return  nmea.isdataready();
     
}     

void GPS::read(void) {
    
    buffer.hour = nmea.getHour();
    buffer.minutes = nmea.getMinute();
    buffer.day = nmea.getDay();
    buffer.month = nmea.getMonth();
    buffer.year = nmea.getYear();
    buffer.latitude = 0.0;
    buffer.longitude = 0.0;

    if (nmea.isdataready()) {
        buffer.latitude = nmea.getLatitude();
        buffer.longitude = nmea.getLongitude();
        buffer.speed = nmea.getSpeed();
        buffer.altitude = nmea.getAltitude();
        buffer.bearing = nmea.getBearing();
        buffer.satellites = nmea.getSatellites();
    }
}