How to read Serial String from arduino as Int on processing?

Jbarnier

Hello, I'm really new to processing and I'm trying to read the values from a potenciometer as int so I can use each value for different things. My code is as it is (obtained from here)

import processing.serial.*;

Serial myPort;  // Create object from Serial class
String val;     // Data received from the serial port
void setup()
{
  // On Windows machines, this generally opens COM1.
  // Open whatever port is the one you're using.
  String portName = Serial.list()[0];
  myPort = new Serial(this, portName, 9600);
}

void draw()
{
  if ( myPort.available() > 0) 
  {  // If data is available,
  val = myPort.readStringUntil('\n');         // read it and store it in val
  } 

println(val); //print it out in the console
}

I really appreciate any help, I'm really at a blank here as I don't really know where to start searching. Thanks

kfrajer

Do you need help with your arduino or processing data? That Processing data looks ok.

Kf

Jbarnier

with processing, I guess I misunderstood the forum organization, I will ask in the processing code section

kfrajer

No need to create another post. Your post is in the right section. I don't understand from your post what is missing. I mean, the processing code seems to be ok.

Maybe this line: int y = Integer.parseInt(val); Remember, Processing is just Java.

Kf

Jbarnier

Yes, sorry, I'll try to clarify myself. What I have is processing receiving the nalogRead() numbers from arduino and printing them to the console to verify that it is indeed receiving them. All good here, but what I want is to use those numbers to modify an Image through pixel sorting, so for example arduin is sending 4.3 as a value i need that value to arrange the pixels in a certain way, what I'm missing is the Int, as I have read.

I tried Integer.parseInt() but it send me this: NumberFormatException: Null

Again sorry if something doesn't make sense, I'm new to even java

kfrajer

If you are sending 4.3 then you should be working with float values instead. The sorting will happen only when you receive a new value? It should work like this then:

import processing.serial.*;

Serial myPort;  // Create object from Serial class
String val;     // Data received from the serial port
boolean triggerSorting;

void setup()
{
  // On Windows machines, this generally opens COM1.
  // Open whatever port is the one you're using.
  String portName = Serial.list()[0];
  myPort = new Serial(this, portName, 9600);
  triggerSorting=false;
}

void draw()
{
  if ( myPort.available() > 0)
  {  // If data is available,
    val = myPort.readStringUntil('\n');         // read it and store it in val
    int intVal = Integer.parseInt(val.trim());

    //For example, if potentiometer value is larger than 10, trigger sorting
    //The value of 10 is arbitrary and chosen for demonstration purposes.
    if(intVal>10){
      triggerSorting=true;
    }
  }

  //NEXT performs sorting only if it has received proper data
  if(triggerSorting==true){

    //
    //.....DO YOUR SORTING OPERATION HERE
    //

    triggerSorting=false; //RESET for next read operation
  }

  println(val); //print it out in the console
}

Kf

Jbarnier

yes you are right, it should be float, not int, so I guess the int intVal = Integer.parseInt(val.trim()); should change for a float converter? (while runing it sends error NumberFormatException: for input string "1.21")

kfrajer

This should solve it: float f = Float.parseFloat("25");

Kf

Jbarnier

Thank you!! it's working perfectly now

Lord_of_the_Galaxy

Actually, if you're using the Processing IDE, you can just use int("25") and float("25") instead of Integer.parseInt("25") and Float.parseFloat("25")