This is just a simple Processing program and its corresponding Arduino program for controlling the digital pins of Arduino. It is done by using the processing serial library Processing code import processing.serial.*; Serial n; color c1,c2,c3; color h1,h2; boolean onb0=false; boolean onb1=false; boolean onb2=false; boolean onb3=false; boolean onb4=false; boolean onb5=false; boolean onb6=false; boolean onb7=false; boolean onb8=false; boolean onb9=false; boolean onb10=false; boolean onb11=false; boolean onb12=false; boolean offb0=false; boolean offb1=false; boolean offb2=false; boolean offb3=false; boolean offb4=false; boolean offb5=false; boolean offb6=false; boolean offb7=false; boolean offb8=false; boolean offb9=false; boolean offb10=false; boolean offb11=false; boolean offb12=false; boolean onb13=false; boolean offb13=false; void setup() { size(800,800); n=new Serial(this,"/dev/ttyUSB0",9600); c1=color(80); h1=color(255,0,0); c2=color(255); h2=color(0,255,