Ultrasonic sensors and processing (newbie)

Projects General Guidance
1

Hi everyone! I'm new here and have some questions regarding my project.
I have 2 ultrasonic sensors to get X and Y distance and I'm plotting that data via processing.

The first issue is that Processing script will randomly open, sometimes it gives "Error, disabling serialEvent() for COM3", the other times console just gives null. Not sure what is the problem here?

The other thing the plot in processing (my code). I want it to start drawing in the middle, which it is but it "slides" in from other coordinate.

2001×1006 20.7 KB

Its always random but anyway it start drawing then it slides to center.
I'm pretty new to java, have experience in other languages,but processing does some stuff differently.

In the processing code there are some "hacks" so I could store some position.

Arduino code

const int TRIGX = 4;
const int ECHOX = 5;

const int TRIGY = 6;
const int ECHOY = 7;

int startX;
int startY;

const int numReadings = 10;
int readingsX[numReadings];
int readingsY[numReadings];
int readIndex = 0;
int totalx = 0;
int totaly = 0;
int averagex = 0;
int averagey = 0;

void setup (){

Serial.begin(9600);
pinMode(TRIGX, OUTPUT);
pinMode(ECHOX, INPUT);
pinMode(TRIGY, OUTPUT);
pinMode(ECHOY, INPUT); 


  for (int thisReading = 0; thisReading < numReadings; thisReading++){
    readingsX[thisReading]=0;
    readingsY[thisReading]=0;
  }
}

double GetUltra ( int trig , int echo){

digitalWrite(trig , LOW);

delayMicroseconds(2);

digitalWrite(trig, HIGH);

delayMicroseconds(10);

digitalWrite(trig, LOW);

double distance = ( pulseIn(echo, HIGH,32760) )* 343.2 / 2000; return distance;

}
void loop (){
  /*
  if (!startX){
    startX = GetUltra(TRIGX,ECHOX);  
  }
  if (!startY){
    startY = GetUltra(TRIGY,ECHOY);  
  }
  
  int newX = GetUltra(TRIGX,ECHOX);
  int dataX = startX - newX;
  */
  
  int dataY = GetUltra(TRIGY,ECHOY);
  int dataX = GetUltra(TRIGX,ECHOX);
  
  totalx = totalx - readingsX[readIndex];
  totaly = totaly - readingsY[readIndex];
  
  readingsX[readIndex]= dataX;
  readingsY[readIndex]= dataY;

  /*
  if (dataX < 3000 ){
    readingsX[readIndex]= dataX;
  }
  if (dataY < 3000 ){
    readingsY[readIndex]= dataY;
  }
  */
  
  totalx = totalx + readingsX[readIndex];
  totaly = totaly + readingsY[readIndex];
  readIndex = readIndex + 1;
  if (readIndex >= numReadings){
    readIndex = 0;
  }
  
  averagex = totalx / numReadings;
  averagey = totaly / numReadings;
  
  Serial.print(averagex);Serial.print(' ');Serial.print(averagey);
  Serial.println();
  delay(20);

}

processing code

import processing.serial.*;

private int PORT_NUMBER = 0;
private int SERIAL_RATE = 9600;
Serial inputPort;
private String inputString;

private String start = "false";
private float rawX;
private float curX;
private float curY;
private float LX;
private float LY;
private float startX = 0.01;

void setup(){
  size(2000,1000);
  String portName = Serial.list()[PORT_NUMBER];
  inputPort = new Serial(this, portName, SERIAL_RATE);
  drawAxes();
  delay(1000);
}

void draw(){
  rawX = curX - startX;
  
    strokeWeight(5);
  if (rawX < -50 && rawX > -100 ){
    stroke(157,24,100);
  }
  else if (rawX < -100 && rawX > -200 ){
    stroke(177,14,50);
  }
  else if (rawX < -200){
    stroke(200,0,0);
  }
  else {
    stroke(127,34,255);
  }
  
  line(width/2 - rawX, height - curY,width/2 - LX, height - LY);
  LX = rawX;
  LY = curY;
  
}

void drawAxes() {
  background(0);
  stroke(255,255,255,150);
  strokeWeight(1);
  line(width/2,0,width/2,height);
  stroke(127,34,255);
  line(0,(height/4*3.5),width,(height/4*3.5));
}

void mouseReleased(){
  start = "false";
  drawAxes();
}

void serialEvent(Serial inputPort){
  if (inputPort.available() > 0) {
    inputString = inputPort.readStringUntil('\n');
    if (inputString != null){
      float[] nums = float(splitTokens(inputString));
      curX = nums[0];
      curY = nums[1];
      if (start == "false"){
        startX = curX;
        start = "true";
      }
      //curX = map(curX,0, 2000,0,width);
      curY = map(curY,0, 2000,0,height);
    }
  }
}

I would appreciate any help for these two issues.
Thank you very much!

2

This forum is for Arduino problems. Although someone here may know Processing well enough to help you, it may be a while before they see your post. Posting to the Processing forum would probably get you help faster.

3

Cannot post there since currently you can't register at the moment.

Anyway fixed first issue with "disabling serialEvent()":

Problem is data (in my case) would not get transmitted always at start (not sure why since in Arduino monitor every thing is fine).Checking if both values are present fixes the issue with the error. I'm sending 2 values from Arduino (have two sensors):

Processing code

void serialEvent(Serial inputPort){
   if (inputPort.available() > 0){
      inputString = inputPort.readStringUntil('\n');
      if (inputString != null){
         float[]vals = float(splitTokens(inputString,",");
         if (nums.length < 2) return; // ADDING THIS LINE FIXED SERIAL DISABLE ISSUE,SINCE 
         SOMETIMES ONE VALUE WOULD NOT ARRIVE FOR SOME REASON
         x = vals[0];
         y = vals[1];
      } 
   }
}
4

Fixed the second issue also, added bigger delay in the setup (2000), so the values can be initialized better

Anyway found many other issues regarding getting data which I assume is coming from the fact that Processing and arduino are not in sync (processing checks input much faster then arduino is outputing them).

Found AP Sync library, everything works much much better now and manipulating with data is more flexible IMO.

Not a single issue/error was with AP Sync, easier to setup and manipulate with variable later (at least for me)