so I have been playing w/ arduinos for a few weeks now, and I am tackling processing as my next step, and it is kicking my butt.  As a "hello world" of graphics, i decided to draw a rectangle that gets bigger and smaller (end goal is bar graph that shows some arduino output).  However using IF statments I get rectangle that only grows or shrinks, as if it never hits the if limits.  if I use a while statment, I get a blank window which I can not close.  is it my code? am I insane? what am I missing?

1.   int[] RCTime = {1800, 1500};
2. //  RCTime[0] = 1800;
3. //  RCTime[1] = 1500;
4.   int i=6;
5.  
6. void setup(){
7.   size(300,500);
8. }
9. void draw(){
10.   background(255);
11.   fill(0);
12.   rectMode(CENTER);
13.   if(i < 4){
14.     RCTime[1]=RCTime[1]+25;
15.     rect(150,250,30,RCTime[1]/10); 
16.     i=i++;
17.   }
18.   if(i>2){
19.     RCTime[1]=RCTime[1]-25;
20.     rect(150,250,30,RCTime[1]/10); 
21.     i=i--;
22.   }
23. }

I have run a few pieces of example code and they seem to work fine on my laptop.