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// Neopixel Algorithmic Art |
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// W2812 RGB Neopixel version |
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// Ed Nisley – KE4ZNU |
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#include <Adafruit_NeoPixel.h> |
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#include <Entropy.h> |
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//———- |
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// Pin assignments |
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const byte PIN_NEO = A3; // DO – data out to first Neopixel |
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const byte PIN_HEARTBEAT = 13; // DO – Arduino LED |
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#define PIN_MORSE 12 |
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//———- |
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// Constants |
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// number of pixels |
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#define PIXELS 4 |
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// lag between adjacent pixels in degrees of slowest period |
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#define PIXELPHASE 1 |
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// update LEDs only this many ms apart (minus loop() overhead) |
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#define UPDATEINTERVAL 50ul |
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#define UPDATEMS (UPDATEINTERVAL – 0ul) |
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// number of steps per cycle, before applying prime factors |
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#define RESOLUTION 500 |
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//———- |
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// Globals |
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Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXELS, PIN_NEO, NEO_GRB + NEO_KHZ800); |
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uint32_t FullWhite = strip.Color(255,255,255); |
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uint32_t FullOff = strip.Color(0,0,0); |
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uint32_t MorseColor; |
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struct pixcolor_t { |
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unsigned int Prime; |
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unsigned int NumSteps; |
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unsigned int Step; |
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float StepSize; |
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float Phase; |
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byte MaxPWM; |
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}; |
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unsigned long int TotalSteps; |
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unsigned long int SuperCycleSteps; |
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byte PrimeList[] = {3,5,7,11,13,17,19,29}; // small primes = faster changes |
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// colors in each LED and their count |
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enum pixcolors {RED, GREEN, BLUE, PIXELSIZE}; |
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struct pixcolor_t Pixel[PIXELSIZE]; // all the data for each pixel color intensity |
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uint32_t UniColor; |
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unsigned long int MillisNow; |
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unsigned long int MillisThen; |
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//– Select three unique primes for the color generator function |
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// Then compute all the step parameters based on those values |
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void SetColorGenerators(void) { |
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Pixel[RED].Prime = PrimeList[random(sizeof(PrimeList))]; |
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do { |
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Pixel[GREEN].Prime = PrimeList[random(sizeof(PrimeList))]; |
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} while (Pixel[RED].Prime == Pixel[GREEN].Prime); |
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do { |
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Pixel[BLUE].Prime = PrimeList[random(sizeof(PrimeList))]; |
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} while (Pixel[BLUE].Prime == Pixel[RED].Prime || |
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Pixel[BLUE].Prime == Pixel[GREEN].Prime); |
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if (false) { |
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Pixel[RED].Prime = 1; |
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Pixel[GREEN].Prime = 3; |
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Pixel[BLUE].Prime = 5; |
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} |
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printf("Primes: %d %d %d\r\n",Pixel[RED].Prime,Pixel[GREEN].Prime,Pixel[BLUE].Prime); |
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TotalSteps = 0; |
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SuperCycleSteps = RESOLUTION; |
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for (byte c = 0; c < PIXELSIZE; c++) { |
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SuperCycleSteps *= Pixel[c].Prime; |
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} |
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printf(" Super cycle length: %lu steps\r\n",SuperCycleSteps); |
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Pixel[RED].MaxPWM = 255; |
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Pixel[GREEN].MaxPWM = 255; |
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Pixel[BLUE].MaxPWM = 255; |
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unsigned int PhaseSteps = (unsigned int) ((PIXELPHASE / 360.0) * |
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RESOLUTION * (unsigned int) max(max(Pixel[RED].Prime,Pixel[GREEN].Prime),Pixel[BLUE].Prime)); |
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printf("Inter-pixel phase: %d deg = %d steps\r\n",(int)PIXELPHASE,PhaseSteps); |
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for (byte c = 0; c < PIXELSIZE; c++) { |
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Pixel[c].NumSteps = RESOLUTION * Pixel[c].Prime; // steps per cycle |
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Pixel[c].StepSize = TWO_PI / Pixel[c].NumSteps; // radians per step |
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Pixel[c].Step = random(Pixel[c].NumSteps); // current step |
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Pixel[c].Phase = PhaseSteps * Pixel[c].StepSize; // phase in radians for this color |
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printf(" c: %d Steps: %5d Init: %5d Phase: %3d deg",c,Pixel[c].NumSteps,Pixel[c].Step,(int)(Pixel[c].Phase * 360.0 / TWO_PI)); |
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printf(" PWM: %d\r\n",Pixel[c].MaxPWM); |
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} |
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} |
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//– Helper routine for printf() |
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int s_putc(char c, FILE *t) { |
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Serial.write(c); |
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} |
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//—————— |
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// Set the mood |
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void setup() { |
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pinMode(PIN_HEARTBEAT,OUTPUT); |
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digitalWrite(PIN_HEARTBEAT,LOW); // show we arrived |
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Serial.begin(57600); |
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fdevopen(&s_putc,0); // set up serial output for printf() |
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printf("Algorithmic Art\r\n RGB WS2812\r\nEd Nisley – KE4ZNU – April 2020\r\n"); |
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Entropy.initialize(); // start up entropy collector |
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// set up pixels |
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strip.begin(); |
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strip.show(); |
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// lamp test: a brilliant white flash |
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printf("Lamp test: flash full-on colors\r\n"); |
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uint32_t FullRGB = strip.Color(255,255,255); |
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uint32_t FullR = strip.Color(255,0,0); |
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uint32_t FullG = strip.Color(0,255,0); |
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uint32_t FullB = strip.Color(0,0,255); |
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uint32_t FullOff = strip.Color(0,0,0); |
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uint32_t TestColors[] = {FullR,FullG,FullB,FullRGB,FullOff}; |
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for (byte i = 0; i < sizeof(TestColors)/sizeof(uint32_t) ; i++) { |
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printf(" color: %08lx\r\n",TestColors[i]); |
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for (int p=0; p < strip.numPixels(); p++) { |
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strip.setPixelColor(p,TestColors[i]); |
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} |
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strip.show(); |
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delay(1000); |
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} |
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// get an actual random number |
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uint32_t rn = Entropy.random(); |
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printf("Random seed: %08lx\r\n",rn); |
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randomSeed(rn); |
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// set up the color generators |
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SetColorGenerators(); |
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MillisNow = MillisThen = millis(); |
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} |
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//—————— |
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// Run the mood |
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void loop() { |
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MillisNow = millis(); |
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if ((MillisNow – MillisThen) >= UPDATEMS) { // time for another step? |
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digitalWrite(PIN_HEARTBEAT,HIGH); |
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TotalSteps++; |
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strip.show(); // send out precomputed colors |
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for (byte c = 0; c < PIXELSIZE; c++) { // compute next increment for each color |
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if (++Pixel[c].Step >= Pixel[c].NumSteps) { |
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Pixel[c].Step = 0; |
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printf("Color %-5d steps %-5d at %-8ld ms %-8ld TS %-8lu\r\n", |
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c,Pixel[c].NumSteps,MillisNow,(MillisNow – MillisThen),TotalSteps); |
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} |
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} |
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// If all cycles have completed, reset the color generators |
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if (TotalSteps >= SuperCycleSteps) { |
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printf("Supercycle end, setting new color values\r\n"); |
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SetColorGenerators(); |
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} |
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for (int p = 0; p < strip.numPixels(); p++) { // for each pixel |
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byte Value[PIXELSIZE]; |
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for (byte c=0; c < PIXELSIZE; c++) { // compute new colors |
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Value[c] = (Pixel[c].MaxPWM / 2.0) * (1.0 + sin(Pixel[c].Step * Pixel[c].StepSize – p*Pixel[c].Phase)); |
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} |
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UniColor = strip.Color(Value[RED],Value[GREEN],Value[BLUE]); |
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strip.setPixelColor(p,UniColor); |
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} |
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MillisThen = MillisNow; |
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digitalWrite(PIN_HEARTBEAT,LOW); |
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} |
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} |
The Smell of Molten Projects in the Morning 