I'm doing a project using a pressure sensor and an arduino to read the results and using processing the graph it. i would like to add numbers on the x and y axis to make the graphs more valid, my codes are below.
            
             
            
            
             
              
             
             
              
             
             
                
             
             
            
             
            
            
             
            
            
             
               
             
             
              
             
             
               
             
             
               
             
             
              
             
             
                 
             
             
              
             
             
               
             
             
                  
             
             
              
             
             
              
             
             
              
             
             
               
             
             
              
             
             
               
             
             
              
             
             
              
             
            
            
             
             
           
 
            
           
             Arduino code:
            
            
              long readVcc() {
             
             
                long result;
             
             
                // Read 1.1V reference against AVcc
             
             
                ADMUX = _BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
             
             
                delay(2); // Wait for Vref to settle
             
             
                ADCSRA |= _BV(ADSC); // Convert
             
             
                while (bit_is_set(ADCSRA,ADSC));
             
             
                result = ADCL;
             
             
                result |= ADCH<<8;
             
             
                result = 1126400L / result; // Back-calculate AVcc in mV
             
             
                return result;
             
             
              }
             
             
              void setup() {
             
             
                Serial.begin(9600);
             
             
              }
             
             
              void loop() {
             
             
                int sensorValue = analogRead(A0);
             
             
                int A0Vin = ((sensorValue / 102.3)* readVcc());
             
             
                Serial.print("A");
             
             
                Serial.println(A0Vin);  
             
             
                delay(10);
             
             
              }
             
            
             Processing code
            
            
              /**
             
             
               * Serial Read & Write to LogFile
             
             
               *
             
             
               * Read data from Arduino through serial port and appends the data to a text file provided.
             
             
               * Code by: Naveen Karuthedath, Barry Chris & Aradhan
             
             
              */
             
             
              import processing.serial.*;
             
             
              Serial sPort;  
             
             
              String sData;
             
             
              int yCoord;
             
             
              int yCoord2;
             
             
              int[] plot1;
             
             
              int Ypos;
             
             
              String file1 = "C:\Users\George\Documents\Research project\graphing codes\Processing";
             
             
              String comPort = "COM4";
             
             
              int logDelay = 100; //ms delay
             
             
              void setup()
             
             
              {
             
             
                size(640,550);//window size
             
             
                frameRate(100);
             
             
                //if serial port is available
             
             
                try {
             
             
                 sPort = new Serial(this, comPort, 9600);
             
             
                 // don’t read the serial buffer until a new line char
             
             
                 // should use Serial.println("") in arduino code
             
             
                } finally {}
             
             
                plot1 = new int[551];
             
             
                Ypos = 1;    
             
             
              for (int i = 0; i < plot1.length; i++){  
             
             
                plot1[i] = 0;  
             
             
              }
             
             
              }
             
             
              void draw()
             
             
              {
             
             
                printScreen();
             
             
                // If data is available,
             
             
                if (sPort.available() > 0) { 
             
             
                  sData =  sPort.readStringUntil('\n'); 
             
             
                      //sData =  sPort.readString();
             
             
                  logData(file1,getDateTime() + yCoord2 + System.getProperty("line.separator"),true);
             
             
                  println(sData);
             
             
                  sData = trim(sData);
             
             
                }
             
             
              if (sData != null) {
             
             
              if (sData.charAt(0) == 'A'){
             
             
                yCoord = int(sData.substring(1));
             
             
                yCoord2 = (yCoord / 100);
             
             
                println(yCoord2);
             
             
                   }
             
             
              }
             
             
              // THESE ARE THE PULSE SENSOR WAVEFORM DRAWING ROUTINES
             
             
              // fisrt, move the Y coordintae of previous pulse data points over one pixel to the left
             
             
               for (int i = 0; i < plot1.length-1; i++){  
             
             
                 plot1[i] = plot1[i+1];     
             
             
               }
             
             
              // new data enters on the right of the screen. sensor value is placed in the last array position
             
             
              Ypos = yCoord2;
             
             
              plot1[plot1.length-1] = Ypos;  // Ypos is updated in the serialEvent tab
             
             
              // This for loop renders the Pulse Sensor waveform
             
             
               for (int x = 1; x < plot1.length-1; x++){    // variable 'x' will take the place of pixel x position
             
             
                                                   // get ready to make a red line
             
             
              // Here are a few ways to draw the datapoints.    
             
             
              //   line(x+61, pulseY[x]+1, x+61, pulseY[x]-1);          // display previous datapoint as vertical line
             
             
              //   point(x+61,plot1[x]);                               //display previous datapoint as point
             
             
                 ellipse(x+70,plot1[x],1,1);                         // display previous datapoint as a small dot
             
             
              //   line(x+76, plot1[x], x+75, plot1[x-1]);              //display previous datapoint as a connected line
             
             
               redraw();
             
             
               }
             
             
              }
             
             
              void printScreen(){          // DRAW MAJOR SCREEN ELEMENTS AND TEXT
             
             
                 background(0);                           // black background
             
             
                 noStroke();  
             
             
                 fill(255,253,248);
             
             
              }
             
             
              void logData( String fileName, String newData, boolean appendData)
             
             
               {
             
             
                  BufferedWriter bw=null;
             
             
                  try { //try to open the file
             
             
                  FileWriter fw = new FileWriter(fileName, appendData);
             
             
                  bw = new BufferedWriter(fw);
             
             
                  bw.write(newData);// + System.getProperty("line.separator"));
             
             
                  } catch (IOException e) {
             
             
                  } finally {
             
             
                  if (bw != null){ //if file was opened try to close
             
             
                      try {
             
             
                      bw.close();
             
             
                      } catch (IOException e) {}
             
             
                  }
             
             
                  }
             
             
              }
             
             
              String getDateTime()
             
             
              {
             
             
                    SimpleDateFormat df = new SimpleDateFormat("[ dd/MM/yyyy HH:mm:ss ] ");
             
             
                    Calendar date = Calendar.getInstance(); // the current date and time
             
             
                    return(df.format(date.getTime()));
             
             
              }
             
              
              
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