Erik Tryggvason / Mbed 2 deprecated WS2812_Gradient

Displays a gradient between two colors

Dependencies:   PixelArray WS2812 mbed

main.cpp@0:3bb97062a703, 2017-03-12 (annotated)

Committer:
theros
Date:
Sun Mar 12 23:02:59 2017 +0000
Revision:
0:3bb97062a703
First Commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
theros 0:3bb97062a703 1 #include "mbed.h"
theros 0:3bb97062a703 2 #include "WS2812.h"
theros 0:3bb97062a703 3 #include "PixelArray.h"
theros 0:3bb97062a703 4
theros 0:3bb97062a703 5 #define WS2812_BUF 77 //number of LEDs in the array
theros 0:3bb97062a703 6 #define NUM_COLORS 2 //number of colors to store in the array
theros 0:3bb97062a703 7
theros 0:3bb97062a703 8 DigitalOut usrLed(LED1);
theros 0:3bb97062a703 9 PixelArray px(WS2812_BUF);
theros 0:3bb97062a703 10
theros 0:3bb97062a703 11 // See the program page for information on the timing numbers
theros 0:3bb97062a703 12 WS2812 ws(D9, WS2812_BUF, 6,17,9,14); //nucleo-f411re
theros 0:3bb97062a703 13
theros 0:3bb97062a703 14 int color_set(uint8_t red,uint8_t green, uint8_t blue)
theros 0:3bb97062a703 15 {
theros 0:3bb97062a703 16 return ((red<<16) + (green<<8) + blue);
theros 0:3bb97062a703 17 }
theros 0:3bb97062a703 18
theros 0:3bb97062a703 19 // 0 <= stepNumber <= lastStepNumber
theros 0:3bb97062a703 20 int interpolate(int startValue, int endValue, int stepNumber, int lastStepNumber)
theros 0:3bb97062a703 21 {
theros 0:3bb97062a703 22 return (endValue - startValue) * stepNumber / lastStepNumber + startValue;
theros 0:3bb97062a703 23 }
theros 0:3bb97062a703 24
theros 0:3bb97062a703 25 int main()
theros 0:3bb97062a703 26 {
theros 0:3bb97062a703 27 uint8_t ir = 0;
theros 0:3bb97062a703 28 uint8_t ig = 0;
theros 0:3bb97062a703 29 uint8_t ib = 0;
theros 0:3bb97062a703 30
theros 0:3bb97062a703 31 ws.useII(WS2812::PER_PIXEL); // use per-pixel intensity scaling
theros 0:3bb97062a703 32
theros 0:3bb97062a703 33 // set up the colours we want to draw with
theros 0:3bb97062a703 34 int colorbuf[NUM_COLORS] = {0xff0000,0x0000ff};
theros 0:3bb97062a703 35
theros 0:3bb97062a703 36 //get starting RGB components for interpolation
theros 0:3bb97062a703 37 std::size_t c1 = colorbuf[0];
theros 0:3bb97062a703 38 std::size_t r1 = (c1 & 0xff0000) >> 16;
theros 0:3bb97062a703 39 std::size_t g1 = (c1 & 0x00ff00) >> 8;
theros 0:3bb97062a703 40 std::size_t b1 = (c1 & 0x0000ff);
theros 0:3bb97062a703 41
theros 0:3bb97062a703 42 //get ending RGB components for interpolation
theros 0:3bb97062a703 43 std::size_t c2 = colorbuf[1];
theros 0:3bb97062a703 44 std::size_t r2 = (c2 & 0xff0000) >> 16;
theros 0:3bb97062a703 45 std::size_t g2 = (c2 & 0x00ff00) >> 8;
theros 0:3bb97062a703 46 std::size_t b2 = (c2 & 0x0000ff);
theros 0:3bb97062a703 47
theros 0:3bb97062a703 48 for (int i = 0; i <= WS2812_BUF; i++)
theros 0:3bb97062a703 49 {
theros 0:3bb97062a703 50 ir = interpolate(r1, r2, i, WS2812_BUF);
theros 0:3bb97062a703 51 ig = interpolate(g1, g2, i, WS2812_BUF);
theros 0:3bb97062a703 52 ib = interpolate(b1, b2, i, WS2812_BUF);
theros 0:3bb97062a703 53
theros 0:3bb97062a703 54 //write the color value for each pixel
theros 0:3bb97062a703 55 px.Set(i, color_set(ir,ig,ib));
theros 0:3bb97062a703 56
theros 0:3bb97062a703 57 //write the II value for each pixel
theros 0:3bb97062a703 58 px.SetI(i, 32);
theros 0:3bb97062a703 59 }
theros 0:3bb97062a703 60
theros 0:3bb97062a703 61 for (int i = WS2812_BUF; i >= 0; i--)
theros 0:3bb97062a703 62 {
theros 0:3bb97062a703 63 ws.write(px.getBuf());
theros 0:3bb97062a703 64 }
theros 0:3bb97062a703 65
theros 0:3bb97062a703 66 usrLed = 1;
theros 0:3bb97062a703 67 }