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

JbarnierJbarnier
in Arduino

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

Best Answer

Answers

  • kfrajerkfrajer

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

    Kf

  • JbarnierJbarnier

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

  • kfrajerkfrajer

    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

  • JbarnierJbarnier

    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

  • kfrajerkfrajer

    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

  • JbarnierJbarnier

    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")

  • kfrajerkfrajer
    Answer ✓

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

    Kf

  • JbarnierJbarnier

    Thank you!! it's working perfectly now

  • Lord_of_the_GalaxyLord_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")

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