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#include <FastLED.h> #define LED_PIN 5 #define COLOR_ORDER GRB #define CHIPSET WS2811 #define BRIGHTNESS 64 // Helper functions for an two-dimensional XY matrix of pixels. // Simple 2-D demo code is included as well. // // XY(x,y) takes x and y coordinates and returns an LED index number, // for use like this: leds[ XY(x,y) ] == CRGB::Red; // No error checking is performed on the ranges of x and y. // // XYsafe(x,y) takes x and y coordinates and returns an LED index number, // for use like this: leds[ XYsafe(x,y) ] == CRGB::Red; // Error checking IS performed on the ranges of x and y, and an // index of "-1" is returned. Special instructions below // explain how to use this without having to do your own error // checking every time you use this function. // This is a slightly more advanced technique, and // it REQUIRES SPECIAL ADDITIONAL setup, described below. // Params for width and height const uint8_t kMatrixWidth = 8; const uint8_t kMatrixHeight = 8; // Param for different pixel layouts const bool kMatrixSerpentineLayout = true; const bool kMatrixVertical = false; // Set 'kMatrixSerpentineLayout' to false if your pixels are // laid out all running the same way, like this: // // 0 > 1 > 2 > 3 > 4 // | // .----<----<----<----' // | // 5 > 6 > 7 > 8 > 9 // | // .----<----<----<----' // | // 10 > 11 > 12 > 13 > 14 // | // .----<----<----<----' // | // 15 > 16 > 17 > 18 > 19 // // Set 'kMatrixSerpentineLayout' to true if your pixels are // laid out back-and-forth, like this: // // 0 > 1 > 2 > 3 > 4 // | // | // 9 < 8 < 7 < 6 < 5 // | // | // 10 > 11 > 12 > 13 > 14 // | // | // 19 < 18 < 17 < 16 < 15 // // Bonus vocabulary word: anything that goes one way // in one row, and then backwards in the next row, and so on // is call "boustrophedon", meaning "as the ox plows." // This function will return the right 'led index number' for // a given set of X and Y coordinates on your matrix. // IT DOES NOT CHECK THE COORDINATE BOUNDARIES. // That's up to you. Don't pass it bogus values. // // Use the "XY" function like this: // // for( uint8_t x = 0; x < kMatrixWidth; x++) { // for( uint8_t y = 0; y < kMatrixHeight; y++) { // // // Here's the x, y to 'led index' in action: // leds[ XY( x, y) ] = CHSV( random8(), 255, 255); // // } // } // // uint16_t XY( uint8_t x, uint8_t y) { uint16_t i; if( kMatrixSerpentineLayout == false) { if (kMatrixVertical == false) { i = (y * kMatrixWidth) + x; } else { i = kMatrixHeight * (kMatrixWidth - (x+1))+y; } } if( kMatrixSerpentineLayout == true) { if (kMatrixVertical == false) { if( y & 0x01) { // Odd rows run backwards uint8_t reverseX = (kMatrixWidth - 1) - x; i = (y * kMatrixWidth) + reverseX; } else { // Even rows run forwards i = (y * kMatrixWidth) + x; } } else { // vertical positioning if ( x & 0x01) { i = kMatrixHeight * (kMatrixWidth - (x+1))+y; } else { i = kMatrixHeight * (kMatrixWidth - x) - (y+1); } } } return i; } // Once you've gotten the basics working (AND NOT UNTIL THEN!) // here's a helpful technique that can be tricky to set up, but // then helps you avoid the needs for sprinkling array-bound-checking // throughout your code. // // It requires a careful attention to get it set up correctly, but // can potentially make your code smaller and faster. // // Suppose you have an 8 x 5 matrix of 40 LEDs. Normally, you'd // delcare your leds array like this: // CRGB leds[40]; // But instead of that, declare an LED buffer with one extra pixel in // it, "leds_plus_safety_pixel". Then declare "leds" as a pointer to // that array, but starting with the 2nd element (id=1) of that array: // CRGB leds_with_safety_pixel[41]; // CRGB* const leds( leds_plus_safety_pixel + 1); // Then you use the "leds" array as you normally would. // Now "leds[0..N]" are aliases for "leds_plus_safety_pixel[1..(N+1)]", // AND leds[-1] is now a legitimate and safe alias for leds_plus_safety_pixel[0]. // leds_plus_safety_pixel[0] aka leds[-1] is now your "safety pixel". // // Now instead of using the XY function above, use the one below, "XYsafe". // // If the X and Y values are 'in bounds', this function will return an index // into the visible led array, same as "XY" does. // HOWEVER -- and this is the trick -- if the X or Y values // are out of bounds, this function will return an index of -1. // And since leds[-1] is actually just an alias for leds_plus_safety_pixel[0], // it's a totally safe and legal place to access. And since the 'safety pixel' // falls 'outside' the visible part of the LED array, anything you write // there is hidden from view automatically. // Thus, this line of code is totally safe, regardless of the actual size of // your matrix: // leds[ XYsafe( random8(), random8() ) ] = CHSV( random8(), 255, 255); // // The only catch here is that while this makes it safe to read from and // write to 'any pixel', there's really only ONE 'safety pixel'. No matter // what out-of-bounds coordinates you write to, you'll really be writing to // that one safety pixel. And if you try to READ from the safety pixel, // you'll read whatever was written there last, reglardless of what coordinates // were supplied. #define NUM_LEDS (kMatrixWidth * kMatrixHeight) CRGB leds_plus_safety_pixel[ NUM_LEDS + 1]; CRGB* const leds( leds_plus_safety_pixel + 1); uint16_t XYsafe( uint8_t x, uint8_t y) { if( x >= kMatrixWidth) return -1; if( y >= kMatrixHeight) return -1; return XY(x,y); } // Demo that USES "XY" follows code below void loop() { leds[0] = CRGB(0, 255, 255); leds[1] = CRGB(0, 255, 255); leds[2] = CRGB(0, 255, 255); leds[3] = CRGB(0, 255, 255); leds[4] = CRGB(0, 255, 255); leds[5] = CRGB(0, 255, 255); leds[6] = CRGB(0, 255, 255); leds[7] = CRGB(0, 255, 255); leds[8] = CRGB(0, 0, 255); leds[9] = CRGB(255, 255, 255); leds[10] = CRGB(0, 0, 255); leds[11] = CRGB(255, 255, 255); leds[12] = CRGB(0, 0, 255); leds[13] = CRGB(255, 255, 255); leds[14] = CRGB(0, 0, 255); leds[15] = CRGB(255, 255, 255); leds[16] = CRGB(0, 255, 255); leds[17] = CRGB(0, 255, 255); leds[18] = CRGB(0, 255, 255); leds[19] = CRGB(0, 255, 255); leds[20] = CRGB(0, 255, 255); leds[21] = CRGB(0, 255, 255); leds[22] = CRGB(0, 255, 255); leds[23] = CRGB(0, 255, 255); leds[24] = CRGB(0, 0, 255); leds[25] = CRGB(255, 255, 255); leds[26] = CRGB(0, 0, 255); leds[27] = CRGB(255, 255, 255); leds[28] = CRGB(0, 0, 255); leds[29] = CRGB(255, 255, 255); leds[30] = CRGB(0, 0, 255); leds[31] = CRGB(255, 255, 255); leds[32] = CRGB(0, 255, 255); leds[33] = CRGB(0, 255, 255); leds[34] = CRGB(0, 255, 255); leds[35] = CRGB(0, 255, 255); leds[36] = CRGB(0, 255, 255); leds[37] = CRGB(0, 255, 255); leds[38] = CRGB(0, 255, 255); leds[39] = CRGB(0, 255, 255); leds[40] = CRGB(0, 0, 255); leds[41] = CRGB(255, 255, 255); leds[42] = CRGB(0, 0, 255); leds[43] = CRGB(255, 255, 255); leds[44] = CRGB(0, 0, 255); leds[45] = CRGB(255, 255, 255); leds[46] = CRGB(0, 0, 255); leds[47] = CRGB(255, 255, 255); leds[48] = CRGB(0, 255, 255); leds[49] = CRGB(0, 255, 255); leds[50] = CRGB(0, 255, 255); leds[51] = CRGB(0, 255, 255); leds[52] = CRGB(0, 255, 255); leds[53] = CRGB(0, 255, 255); leds[54] = CRGB(0, 255, 255); leds[55] = CRGB(0, 255, 255); leds[56] = CRGB(0, 0, 255); leds[57] = CRGB(255, 255, 255); leds[58] = CRGB(0, 0, 255); leds[59] = CRGB(255, 255, 255); leds[60] = CRGB(0, 0, 255); leds[61] = CRGB(255, 255, 255); leds[62] = CRGB(0, 0, 255); leds[63] = CRGB(255, 255, 255); FastLED.show(); } void setup() { FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalSMD5050); FastLED.setBrightness( BRIGHTNESS ); }
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