I won’t bore you too much with this, but it is really starting to annoy me. I have spent a lot of time scouring the internet for LED cube code over the last year or so and I have lost count of the number of times that I have come across this particular form of code.
#include <avr/pgmspace.h> // allows use of PROGMEM to store patterns in flash
#define CUBESIZE 4
#define PLANESIZE CUBESIZE*CUBESIZE
#define PLANETIME 3333 // time each plane is displayed in us -> 100 Hz refresh
#define TIMECONST 20 // multiplies DisplayTime to get ms - why not =100?
// LED Pattern Table in PROGMEM - last column is display time in 100ms units
// TODO this could be a lot more compact but not with binary pattern representation
prog_uchar PROGMEM PatternTable[] = {
// blink on and off
B0001,B0000,B0000,B0000,B0001,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,10,
B0011,B0000,B0000,B0000,B0011,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,B0000,10,
// More data of the above form
int LEDPin[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
int PlanePin[] = {16, 17, 18, 19};
// initialization
void setup()
{
int pin; // loop counter
// set up LED pins as output (active HIGH)
for (pin=0; pin<PLANESIZE; pin++) {
pinMode( LEDPin[pin], OUTPUT );
}
// set up plane pins as outputs (active LOW)
for (pin=0; pin<CUBESIZE; pin++) {
pinMode( PlanePin[pin], OUTPUT );
}
}
// display pattern in table until DisplayTime is zero (then repeat)
void loop()
{
// declare variables
byte PatternBuf[PLANESIZE]; // saves current pattern from PatternTable
int PatternIdx;
byte DisplayTime; // time*100ms to display pattern
unsigned long EndTime;
int plane; // loop counter for cube refresh
int patbufidx; // indexes which byte from pattern buffer
int ledrow; // counts LEDs in refresh loop
int ledcol; // counts LEDs in refresh loop
int ledpin; // counts LEDs in refresh loop
// Initialize PatternIdx to beginning of pattern table
PatternIdx = 0;
// loop over entries in pattern table - while DisplayTime>0
do {
// read pattern from PROGMEM and save in array
memcpy_P( PatternBuf, PatternTable+PatternIdx, PLANESIZE );
PatternIdx += PLANESIZE;
// read DisplayTime from PROGMEM and increment index
DisplayTime = pgm_read_byte_near( PatternTable + PatternIdx++ );
// compute EndTime from current time (ms) and DisplayTime
EndTime = millis() + ((unsigned long) DisplayTime) * TIMECONST;
// loop while DisplayTime>0 and current time < EndTime
while ( millis() < EndTime ) {
patbufidx = 0; // reset index counter to beginning of buffer
// loop over planes
for (plane=0; plane<CUBESIZE; plane++) {
// turn previous plane off
if (plane==0) {
digitalWrite( PlanePin[CUBESIZE-1], HIGH );
} else {
digitalWrite( PlanePin[plane-1], HIGH );
}
// load current plane pattern data into ports
ledpin = 0;
for (ledrow=0; ledrow<CUBESIZE; ledrow++) {
for (ledcol=0; ledcol<CUBESIZE; ledcol++) {
digitalWrite( LEDPin[ledpin++], PatternBuf[patbufidx] & (1 << ledcol) );
}
patbufidx++;
}
// turn current plane on
digitalWrite( PlanePin[plane], LOW );
// delay PLANETIME us
delayMicroseconds( PLANETIME );
} // for plane
} // while <EndTime
} while (DisplayTime > 0); // read patterns until time=0 which signals end
}
Nearly everybody who shows this code, or a close facsimile of, seems to think that they actually wrote it and doesn’t seem to have the common decency to acknowledge the true author of this nice concise piece of coding. Hey look, I am flat out writing my own code of any level of complexity but I would not even think of trying to take credit for someone else's work. Doesn’t this sort of thing go against the whole idea of open source and cooperative interaction between like minded individuals sharing a common interest? I will now step down from my soapbox, and thanks for letting me vent
