Acceleration of pov display

Projects Programming
1

Hi!

I did a pov project following this code, but i would like to speed up the displaying of the letters so that i can have a displaying more fluid.How can i do that?
Here's the code:

/*
##########################
# Arduino POV for 10 LEDs #
##########################

Circuit: 10 LEDs connected to pins 2 to 11 (with resistors, usually 560 ohm)

Each character is given a 10x10 grid to represent it's self
For example "H" is
O 0       0 0
O 0       0 0
O O       0 0
O 0       0 0
O 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0       0 0
0 0       0 0
0 0       0 0
0 0       0 0
each of these vertical lines is made from a single number
for the "H" example the numbers are 31,4,4,4,31

512  O 0       0 0
256  O 0       0 0
128  O O       0 0
64   O 0       0 0
32   O 0 0 0 0 0 0
16   0 0 0 0 0 0 0
8    0 0       0 0
4    0 0       0 0
2    0 0       0 0
1    0 0       0 0

t    1 1 0 0 0 1 1 0 0 0
o    0 0 0 0 0 0 0 0 0 0
t    2 2 4 4 4 2 2 0 0 0
     3 3 8 8 8 3 3 0 0 0

1023 is 512+256+128+64+32+16+8+4+2+1 (all LEDs are lit)
48   is 000+000+000+00+32+16+0+0+0+0  (only the middle 2 LEDs are lit)

thus the definition for h is...
int h[] = {1023,1023,48,48,48,1023,1023,0,0,0};

*/


int delayTime = 2; //sub-char delay time
int charBreak = 5; //char delay time


int LED0 = 3;
int LED1 = 4;
int LED2 = 5;
int LED3 = 6;
int LED4 = 7;
int LED5 = 8;
int LED6 = 9;
int LED7 = 10;
int LED8 = 11;
int LED9 = 12;

void setup()
{
  pinMode(LED0, OUTPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  pinMode(LED5, OUTPUT);
  pinMode(LED6, OUTPUT);
  pinMode(LED7, OUTPUT);
  pinMode(LED8, OUTPUT);
  pinMode(LED9, OUTPUT);  
}

//lets define a font, yay

int a[] = {7,31,248,216,792,792,216,248,31,7};
int b[] = {1023,1023,819,819,478,478,0,0,0,0};
int c2[] = {120,510,390,771,771,771,462,204,0,0};
int d[] = {1023,1023,771,771,390,510,120,0,0,0};
int e[] = {1023,1023,819,819,819,771,771,0,0,0};
int f[] = {1023,1023,816,816,816,768,768,0,0,0};
int g[] = {0,252,510,903,771,795,927,414,24,0};
int h[] = {1023,1023,48,48,48,1023,1023,0,0,0};
int i[] = {771,771,1023,1023,771,771,0,0,0,0};
int j[] = {771,771,1023,1023,768,768,0,0,0,0};
int k[] = {1023,1023,120,204,390,771,513,0,0,0};
int l[] = {1023,1023,3,3,3,3,0,0,0,0};
int m[] = {1023,1023,448,224,56,56,224,448,1023,1023};
int n[] = {1023,1023,448,224,56,28,1023,1023,0,0};
int o[] = {120,252,390,771,771,771,390,252,120,0};
int p[] = {1023,1023,816,816,480,480,0,0,0,0};
int q[] = {120,510,390,771,795,414,510,126,6,0};
int r[] = {1023,1023,816,824,510,199,3,0,0,0};
int s[] = {230,502,947,819,926,396,0,0,0,0};
int t[] = {768,768,768,1023,1023,768,768,768,0,0};
int u[] = {1016,1022,6,3,3,3,6,1022,1016,0};
int v[] = {768,960,240,60,15,15,60,240,960,768};
int w[] = {240,254,7,62,112,62,7,254,240,0};
int x[] = {771,903,462,252,120,120,252,462,903,771};
int y[] = {771,903,462,252,120,112,224,448,896,768};
int z[] = {775,783,799,827,883,995,963,899,0,0};

int eos[] = {3,3,0,0,0,0,0,0,0,0};
int excl[] = {448,1019,1019,448,0,0,0,0,0,0};
int ques[] = {192,448,768,795,795,816,480,192,0,0};
int spa[] = {0,0,0,0,0,0,0,0,0,0};

void displayLine(int line)
{
  int myline;
  myline = line;
  if (myline>=512)  {digitalWrite(LED0, HIGH); myline-=512;}  else {digitalWrite(LED0, LOW);}
  if (myline>=256)  {digitalWrite(LED1, HIGH); myline-=256;}  else {digitalWrite(LED1, LOW);}
  if (myline>=128)  {digitalWrite(LED2, HIGH); myline-=128;}  else {digitalWrite(LED2, LOW);}
  if (myline>=64)   {digitalWrite(LED3, HIGH); myline-=64;}   else {digitalWrite(LED3, LOW);}
  if (myline>=32)   {digitalWrite(LED4, HIGH); myline-=32;}   else {digitalWrite(LED4, LOW);}    
  if (myline>=16)   {digitalWrite(LED5, HIGH); myline-=16;}   else {digitalWrite(LED5, LOW);}
  if (myline>=8)    {digitalWrite(LED6, HIGH); myline-=8;}    else {digitalWrite(LED6, LOW);}
  if (myline>=4)    {digitalWrite(LED7, HIGH); myline-=4;}    else {digitalWrite(LED7, LOW);}
  if (myline>=2)    {digitalWrite(LED8, HIGH); myline-=2;}    else {digitalWrite(LED8, LOW);}
  if (myline>=1)    {digitalWrite(LED9, HIGH); myline-=1;}    else {digitalWrite(LED9, LOW);}  
}

void displayChar(char c)
{
  if (c == 'a'){for (int i = 0; i <10; i++){displayLine(a[i]);delay(delayTime);}displayLine(0);}
  if (c == 'b'){for (int i = 0; i <10; i++){displayLine(b[i]);delay(delayTime);}displayLine(0);}
  if (c == 'c'){for (int i = 0; i <10; i++){displayLine(c2[i]);delay(delayTime);}displayLine(0);}
  if (c == 'd'){for (int i = 0; i <10; i++){displayLine(d[i]);delay(delayTime);}displayLine(0);}
  if (c == 'e'){for (int i = 0; i <10; i++){displayLine(e[i]);delay(delayTime);}displayLine(0);}
  if (c == 'f'){for (int i = 0; i <10; i++){displayLine(f[i]);delay(delayTime);}displayLine(0);}
  if (c == 'g'){for (int i = 0; i <10; i++){displayLine(g[i]);delay(delayTime);}displayLine(0);}
  if (c == 'h'){for (int i = 0; i <10; i++){displayLine(h[i]);delay(delayTime);}displayLine(0);}  
  if (c == 'i'){for (int it = 0; it <10; it++){displayLine(i[it]);delay(delayTime);}displayLine(0);}
  if (c == 'j'){for (int i = 0; i <10; i++){displayLine(j[i]);delay(delayTime);}displayLine(0);}
  if (c == 'k'){for (int i = 0; i <10; i++){displayLine(k[i]);delay(delayTime);}displayLine(0);}
  if (c == 'l'){for (int i = 0; i <10; i++){displayLine(l[i]);delay(delayTime);}displayLine(0);}
  if (c == 'm'){for (int i = 0; i <10; i++){displayLine(m[i]);delay(delayTime);}displayLine(0);}
  if (c == 'n'){for (int i = 0; i <10; i++){displayLine(n[i]);delay(delayTime);}displayLine(0);}
  if (c == 'o'){for (int i = 0; i <10; i++){displayLine(o[i]);delay(delayTime);}displayLine(0);}
  if (c == 'p'){for (int i = 0; i <10; i++){displayLine(p[i]);delay(delayTime);}displayLine(0);}
  if (c == 'q'){for (int i = 0; i <10; i++){displayLine(q[i]);delay(delayTime);}displayLine(0);}
  if (c == 'r'){for (int i = 0; i <10; i++){displayLine(r[i]);delay(delayTime);}displayLine(0);}
  if (c == 's'){for (int i = 0; i <10; i++){displayLine(s[i]);delay(delayTime);}displayLine(0);}
  if (c == 't'){for (int i = 0; i <10; i++){displayLine(t[i]);delay(delayTime);}displayLine(0);}
  if (c == 'u'){for (int i = 0; i <10; i++){displayLine(u[i]);delay(delayTime);}displayLine(0);}
  if (c == 'v'){for (int i = 0; i <10; i++){displayLine(v[i]);delay(delayTime);}displayLine(0);}
  if (c == 'w'){for (int i = 0; i <10; i++){displayLine(w[i]);delay(delayTime);}displayLine(0);}
  if (c == 'x'){for (int i = 0; i <10; i++){displayLine(x[i]);delay(delayTime);}displayLine(0);}
  if (c == 'y'){for (int i = 0; i <10; i++){displayLine(y[i]);delay(delayTime);}displayLine(0);}
  if (c == 'z'){for (int i = 0; i <10; i++){displayLine(z[i]);delay(delayTime);}displayLine(0);}
  if (c == '!'){for (int i = 0; i <10; i++){displayLine(excl[i]);delay(delayTime);}displayLine(0);}
  if (c == '?'){for (int i = 0; i <10; i++){displayLine(ques[i]);delay(delayTime);}displayLine(0);}
  if (c == '.'){for (int i = 0; i <10; i++){displayLine(eos[i]);delay(delayTime);}displayLine(0);}
  if (c == '_'){for (int i = 0; i <10; i++){displayLine(spa[i]);delay(delayTime);}displayLine(0);}
  delay(charBreak);
}

void displayString(char* s)
{
  for (int i = 0; i<=strlen(s); i++)
  {
    displayChar(s[i]);
  }
}

void loop()
{    
  displayString("rock!");
}

Thanks!

2

You could get rid of the digitalWrite calls.
Either use port manipulation, or the "fast" versions of these calls.

3

How de we do that?
Sorry i'm new in the arduino world.

4

http://code.google.com/p/digitalwritefast/
http://www.arduino.cc/playground/Learning/PortManipulation

5

OP, I noticed that you are using delay(), not the best when you do POV, not accurate enough. Direct port manipulation will improve your speed to update but will do nothing to improve the "smoothness" you need. I assume your display shakes back and forth a bit. Use delayMicrosecond(). That is what I did with my displays. Plus, to improve persistence, add a second display to the opposite end of the rotating stage displaying the same thing. If your rotation speed is not very constant, that is a different story.