GPSNMEA字符串的解析代码-ParsingcodeforGPSNMEAstring

i am trying to parse the incoming GPGGA NMEA GPS string using Arduino uno and below code. What i am trying to do is that i am using only GPGGA NMEA string to get the values of Latitude, longitude and altitude.In my below code, i had put certain checks to check if incoming string is GPGGA or not, and then store the further string in a array which can be further parsed suing strtok function and all the 3 GPS coordinates can be easily find out.

我正在尝试使用Arduino uno和下面的代码来解析即将到来的GPGGA NMEA GPS字符串。我要做的是，我只使用GPGGA NMEA字符串来获取纬度、经度和海拔的值。在我下面的代码中，我做了一些检查，检查输入的字符串是否为GPGGA，然后将进一步的字符串存储在一个数组中，使用strtok函数可以对数组进行进一步解析，并且可以很容易地找到所有的3个GPS坐标。

But i am unable to figure out how to store only GPGGA string and not the further string.I am using a for loop but it isn't working.

但是我不知道如何只存储GPGGA字符串而不存储进一步的字符串。我使用for循环，但它不起作用。

I am not trying to use any library.I had came across certain existing codes like this.

我不想使用任何库。我遇到过一些现有的代码。

Here is the GPGGA string information link

这是GPGGA字符串信息链接

i am trying to have following functionlity i) Check if incoming string is GPGGA ii) If yes, then store the following string upto EOL or upto * (followed by checksum for the array) in a array, array length is variable(i am unable to find out solution for this) iii) Then parse the stored array(this is done, i tried this with a different array)

后我试图functionlity i)检查传入的字符串是否GPGGA ii)如果是,然后存储以下字符串到终点或到*(其次是校验和数组)在一个数组,数组的长度是可变的(我无法找出解决方案)iii),那么解析存储阵列(这样做是,我试着用不同的数组)

 #include 

    SoftwareSerial mySerial(10,11);  // 10 RX / 11 TX

    void setup()
    {
    Serial.begin(9600);
    mySerial.begin(9600);
    }

    void loop()
    {
    uint8_t x;
    char gpsdata[65];

    if((mySerial.available()))
    {
    char c = mySerial.read();
    if(c == '$')
      {char c1 = mySerial.read();
       if(c1 == 'G')
         {char c2 = mySerial.read();
          if(c2 == 'P')
            {char c3 = mySerial.read();
             if(c3 == 'G')
               {char c4 = mySerial.read();
                if(c4 == 'G')
                   {char c5 = mySerial.read();
                    if(c5 == 'A')
                       {for(x=0;x<65;x++)
                        { 
                        gpsdata[x]=mySerial.read();


    while (gpsdata[x] == '\r' || gpsdata[x] == '\n')
                    {
                    break;
                    }

                        }

                       }
                       else{
                          Serial.println("Not a GPGGA string");
                        }
                   }
               }

            }     

         }

      }

    }

    Serial.println(gpsdata);
    }

Edit 1: Considering Joachim Pileborg, editing the for loop in the code.

编辑1:考虑Joachim Pileborg，在代码中编辑for循环。

I am adding a pic to show the undefined output of the code.

我添加了一个pic来显示代码的未定义输出。

Input for the code:

输入代码:

$GPGGA,092750.000,5321.6802,N,00630.3372,W,1,8,1.03,61.7,M,55.2,M,,*76
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,19,13,28,070,17,26,23,252,,04,14,186,14*79
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092750.000,A,5321.6802,N,00630.3372,W,0.02,31.66,280511,,,A*43
$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,16,13,28,070,17,26,23,252,,04,14,186,15*77
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092751.000,A,5321.6802,N,00630.3371,W,0.06,31.66,280511,,,A*45

7 个解决方案

char globalString[100];//declare a global sufficiently large to hold you results


void loop() 
{
    int chars = mySerial.available();
    int i;
    char *myString;
    if (chars>0)
    {
        myString = calloc(chars+1, sizeof(char));
        for(i=0;i

import serial
import time
ser = serial.Serial(1)

ser.read(1)
read_val = ("nothing")

gpsfile="gpscord.dat"
l=0

megabuffer=''
def buffThis(s):
        global megabuffer
        megabuffer +=s
def buffLines():
        global megabuffer
        megalist=megabuffer.splitlines()
        megabuffer=megalist.pop()
        return megalist

def readcom():
        ser.write("ati")
        time.sleep(3)
        read_val = ser.read(size=500)
        lines=read_val.split('\n')
        for l in lines:
                if l.startswith("$GPGGA"):
                        if l[:len(l)-3].endswith("*"):
                                outfile=open('gps.dat','w')
                                outfile.write(l.rstrip())
                                outfile.close()

readcom()

while 1==1:
    readcom()

answer=raw_input('not looping , CTRL+C to abort')

$GPGGA,225714.656,5021.0474,N,00412.4420,W,0,00,50.0,0.0,M,18.0,M,0.0,0000*5B