Distress System for Elderly

/* This program captures the push button press and retrieves the GPS location and invokes a webservice to log the button press event.
    Copyright (C) 2016 Jayashree Ravi and Pramoda Ravi

    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 3 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 <http://www.gnu.org/licenses/>.
*/


/*jslint node:true, vars:true, bitwise:true, unparam:true */
/*jshint unused:true */
// Leave the above lines for propper jshinting
//Type Node.js Here :)

console.log("Distress System for Elderly  Copyright (C) 2016  Jayashree Ravi and Pramoda Ravi");


var pushButtonSensor = require('jsupm_grove');

var mraa = require('mraa'); //require mraa

var gpsSensor = require('jsupm_ublox6');

// Create the button object using GPIO pin 4
var button = new pushButtonSensor.GroveButton(4);

// Instantiate a Ublox6 GPS device on uart 0.
var myGPSSensor = new gpsSensor.Ublox6(0);

// Green LED on Digital pin 6
var greenLed = new mraa.Gpio(6);
greenLed.dir(mraa.DIR_OUT);

//Red LED on Digital pin 8
var redLed = new mraa.Gpio(8);
redLed.dir(mraa.DIR_OUT);

if (!myGPSSensor.setupTty(gpsSensor.int_B9600))
{
    console.log("Failed to setup tty port parameters");
    process.exit(0);
}


// Read the input and print, waiting 5 seconds between readings
function readButtonValue() {
    // Turn the green LED on
    greenLed.write(1);
    console.log(button.name() + " value is " + button.value());
    
    if(button.value()==1) {
         
        var gpsStr = encodeURIComponent(getGPSInfo());
        console.log(gpsStr);
        const http = require('http');
        // Turn the red LED on
        redLed.write(1);
        http.get('http://www.mobibootcamp.com/sendMessage?uname=%22j%22&phoneNumber=%227347xxxxxx%22&gps='+gpsStr, function(res) {
            console.log('statusCode: ', res.statusCode);
            console.log('headers: ', res.headers);

            res.on('data', function(d) {
                console.log("data received");
                console.log(d.toString());
                redLed.write(0);
            });

        }).on('error', function(e) {
            console.error(e);
        });
    }
     setTimeout(greenLed.write(0),1000); 
}


function getGPSInfo()
{

    var bufferLength = 256;
    var nmeaBuffer  = new gpsSensor.charArray(bufferLength);
    var latlon;
    // we don't want the read to block in this example, so
    // check to see if data is available first.

    while(myGPSSensor.dataAvailable())
    {
        var rv = myGPSSensor.readData(nmeaBuffer, bufferLength);

        var GPSData, dataCharCode, isNewLine, lastNewLine;
        var numlines= 0;
        if (rv > 0)
        {
            GPSData = "";
            // read only the number of characters
            // specified by myGPSSensor.readData
            for (var x = 0; x < rv; x++)
                GPSData += nmeaBuffer.getitem(x);

            console.log(GPSData);
            var gpsArray = GPSData.toString().split('\n');
            for(var i=0; i<gpsArray.length; i++){
                console.log(gpsArray[i]);
                if(gpsArray[i].indexOf('GPGGA') !== -1){
                    var gpsparts = gpsArray[i].split(',');
                    var lat = gpsparts[2];
                    var lon = gpsparts[4];
                    if(lat && lon){
                        console.log("GPGGA reading:" + gpsArray[i]);
                        return (convertToDecimal(lat)+",-"+convertToDecimal(lon));
                    }else {
                        continue;
                    }
                }

                if(gpsArray[i].indexOf('GPRMC') !== -1){
                    var gpsparts2 = gpsArray[i].split(',');
                    var lat2 = gpsparts[3];
                    var lon2 = gpsparts[5];
                    if(lat2 && lon2){
                        return (convertToDecimal(lat2)+",-"+convertToDecimal(lon2));
                    } else {
                        continue;
                    }
                }
            }
        }

        if (rv < 0) // some sort of read error occured
        {
            console.log("Port read error.");
            process.exit(0);
        }
    }
}

function convertToDecimal(lat){
    var firstpart = +(lat.substring(0,lat.length-7));
    var secondpart = +(lat.substring(lat.length-7));
    var latdecimal = firstpart+(secondpart/60);
    return latdecimal;
}
setInterval(readButtonValue, 5000);