Arduino gps serial data to processing problem

filmmaker..

Arduino gps serial data to processing problem

in Integration and Hardware • 1 year ago

Hello,

I have an em406a gps hooked up to an arduino uno. I am using the tinygps library to interpret the gps data on the arduino and output the lat/lon to the serial. Here is part of the arduino code:

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#include <NewSoftSerial.h>
#include <TinyGPS.h>
#define RXPIN 2
#define TXPIN 3
#define GPSBAUD 4800
TinyGPS gps;
NewSoftSerial uart_gps(RXPIN, TXPIN);
void getgps(TinyGPS &gps);
void setup()
{
Serial.begin(115200);
uart_gps.begin(GPSBAUD);
Serial.println("");
Serial.println("GPS");
Serial.println(" ...waiting for lock... ");
Serial.println("");
}
void loop()
{
while(uart_gps.available())
{
int c = uart_gps.read();
if(gps.encode(c))
{
getgps(gps);
}
}
}
void getgps(TinyGPS &gps)
{
float latitude, longitude;
gps.f_get_position(&latitude, &longitude);
Serial.print(latitude,5);
Serial.print(" ");
Serial.println(longitude,5);
}

I am trying to find a way to output the data to the serial so that in processing I can separate the values. I use the space as a delim for split().

Here is my processing code:

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import processing.serial.*;
Serial myPort;
Float lat;
Float lon;
void setup() {
frameRate(5);
println(Serial.list());
myPort = new Serial(this, Serial.list()[0], 115200);
}
void draw() {
while (myPort.available() > 0) {
String inBuffer = myPort.readString();
if (inBuffer != null) {
String[] nums = split(inBuffer, ' ');
Float lat = float(nums[0]);
Float lon = float(nums[1]);
println(lat+","+lon);
}
}
}

If I do not set the frameRate low the code does not work at all. The problem I keep running into is an exception error for num[1] that says that it is out of bounds. The code usually starts to work but after a little it seems to run into this error.

Does anyone know a good way to send data via serial from arduino to processing so that it can be broken apart in processing into different variables(latitude,longitude,speed,etc.)?

Thanks

Stephen

Replies(2)

Jesse Sco..

Re: Arduino gps serial data to processing problem

1 year ago

Maybe you have to test against the length of the string... if it's getting an ArrayIndexOutOfBounds exception, its likely that at some point your Longitude didn't get recorded, so the value is null...

filmmaker..

Re: Re: Arduino gps serial data to processing problem

1 year ago

I am not sure why there would be a null value for the longitude. In the arduino serial monitor, there is always a value shown. Before I do the split() this code works at any Frame Rate:

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println(inBuffer);

My code for splitting the data is what is causing the problem. I do not know of an effective way to filter the data, or fix the ArrayIndexOutOfBounds exception.

Any ideas?

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