Help me to solve how to draw mandelbrot.

[arduino1445ll]

johnwasser:
I think your problem is that you are using integers where the original program probably uses 'float' type for everything. Maybe this will help:

        float cR = x / 120.0;

float cX = y / 120.0;
        float zR = 0;
        float zX = 0;
        int r = 0;

That's brilliant, it's working! Thank you.
I simplified the code too.

void loop()
{
    tp = ts.getPoint();
    pinMode(XM, OUTPUT);
    pinMode(YP, OUTPUT);
    if (tp.z > MINPRESSURE && tp.z < MAXPRESSURE) {
        for(int y = 170; y > -170; y--){
          for(int x = -240; x < 240; x++){
           float cR = x/120.0;
           float cX = y/120.0;
           float zR = 0;
           float zX = 0;
           int r = 0;
            do{
              r++;
              float old_zR = zR;
              zR = cR+((zR*zR)-(zX*zX));
              zX = (2*old_zR*zX)+cX;
            } while(!(r > 50 || zR > 2));
            if (zR < 2){
                tft.drawPixel(x+240, y+170, BLACK);
            }
            else{
                tft.drawPixel(x+240, y+170, r*500);                  
            }
        }
      }
} }