Touchscreen XY Controller over Serial/Bluetooth: Processing Sketch (Raspberry Pi)

controllerInterface.pde

// Processing 3 sketch: Used on Raspberry Pi with 7" touchscreen.
// Touchscreen tracks XY position of finger and sends as serial data over
// bluetooth. That data is received by MaxMSP patch and used to control
// cutoff frequency and resonance of audio filters, real time.

import processing.serial.*;

Serial port;
int val = 0;
int valueScale = 128;

//main window
void setup() {
  fullScreen();
  printArray(Serial.list());
  port = new Serial(this, Serial.list()[0], 115200);
}

//create touch crosshair vertical line
void verticalLine() {
  line(mouseX, 0, mouseX, height);
}

//create touch crosshair horizontal line
void horizontalLine() {
  line(0, mouseY, width, mouseY);
}

//Get XY coordinates of touch/mouse
void touchLocation() {
  
}

void printLocation() {
  print(mouseX, "\t" , mouseY, "\n");
}

//draw crosshairs that follow touch on screen or mouse
void draw() {
  background(97, 255, 250);
  verticalLine();
  horizontalLine();
  
  int xByte = (mouseX * valueScale)/ width;
  int yByte = (mouseY * valueScale)/ height;
  
  //int xByte = (int)map(mouseX, 0, width, 0, valueScale); //valueScale needs to be 127
  
  port.write(xByte);
  port.write(yByte);
}