梦幻雪花由30颗LED打造，分为17个独立的部分，由Arduino Nano控制。每组LED都可以用PWM调校，这样就可以创作出梦幻视觉效果。
首先打印一个漂亮而简单的雪花，记住要让它可以容纳Arduino Nano。
支撑结构也用于走线，由0.8mm黄铜棒与锡焊接而成。我总共使用了2米的黄铜棒。这是对你的耐心和技巧的一次考验。
首先，我通过弯曲一根黄铜棒并将两端焊接在一起来构建一个核心六边形。通过在六边形的顶部添加另外伸出6个黄铜棒，接地线完成，现在需要将LED的所有阴极引线焊接到其上以产生雪花图案。棘手的部分是添加贴片LED，不妨使用纸板和双面胶带制作的夹具。
接下来是在核心结构下加入Arduino Nano，在其间要留出足够的空间以满足3层黄铜棒接线，这将连接微控制器引脚到所有LED阳极引线。这同样需要极大的耐心。你不仅需要避免电线之间的短路，还要添加限流电阻并使其看起来不错。
叶片LED分别连接到最近的Arduino输出引脚。分支LED按两个分组并连接到PWM引脚。核心LED也按两个分组并连接到其余引脚。Arduino NANO只有18个输出引脚，我需要一个引脚用于触摸传感器，这只留下17个引脚，因此两对核心LED连接在一起形成一组4个。我使用220Ω电阻将每个引脚流过的电流限制在8mA左右。这意味着总共240mA，这对ATmega328芯片来说有点高，但它可以工作——安全最大值据说是200mA。
为了能够与雪花相互作用，我添加了另一个黄铜棒来制作电容式触摸传感器。
在焊接之前不要忘记随时检查所有二极管，如果开路或者反极性连接会很难更换它。
原理图
源代码
#include "SoftPWM.h"
#include <ADCTouchSensor.h>
byte edgeLedPins[] = {13, A4, A5, 2, 8, 12};
byte middleLedPins[] = {10, 6, 3, 5, 9, 11};
byte innerLedPins[] = {A2, A3, A1, 4, 7, A1};
ADCTouchSensor touchSensor = ADCTouchSensor(A0, 1);
void setup() {
Serial.begin(115200);
SoftPWMBegin();
}
byte animation = 0;
long touchAt = 0;
void loop() {
switch (animation) {
case 0:
_fill(100);
break;
case 1:
shinyAnimation();
//fadingAnimation();
break;
case 2:
circleAnimation();
break;
case 3:
loopAnimation();
break;
case 4:
fireworkAnimation();
fireworkAnimation();
fireworkAnimation();
fireworkAnimation();
fireworkAnimation();
fireworkAnimation();
animation ++;
break;
case 5:
smileAnimation();
break;
default:
animation = 0;
break;
}
int touchValue = touchSensor.read();
if (touchAt + 2000 < millis() && touchValue > 1000) {
touchAt = millis(); // touch down, cold down timeout is 2s
animation ++;
_fill(0);
}
}
void fireworkAnimation() {
for (int i = 0; i < 4; i++) {
SoftPWMSet(innerLedPins[i], 100);
delay(100);
}
SoftPWMSet(innerLedPins[4], 100);
for (int i = 0; i < 6; i++) {
SoftPWMSet(middleLedPins[i], 255);
}
delay(50);
for (int i = 0; i < 6; i++) {
SoftPWMSet(innerLedPins[i], 0);
SoftPWMSet(edgeLedPins[i], 255);
}
delay(50);
for (int i = 0; i < 6; i++) {
SoftPWMSet(middleLedPins[i], 0);
}
delay(50);
_fill(0);
}
void smileAnimation() {
SoftPWMSet(innerLedPins[1], 100);
SoftPWMSet(innerLedPins[3], 100);
SoftPWMSet(middleLedPins[0], 255);
SoftPWMSet(middleLedPins[5], 255);
SoftPWMSet(edgeLedPins[2], 255);
SoftPWMSet(edgeLedPins[3], 255);
delay(2000);
SoftPWMSet(innerLedPins[1], 0);
SoftPWMSet(innerLedPins[3], 0);
delay(100);
SoftPWMSet(innerLedPins[1], 100);
SoftPWMSet(innerLedPins[3], 100);
delay(100);
SoftPWMSet(innerLedPins[1], 0);
SoftPWMSet(innerLedPins[3], 0);
delay(100);
}
byte circleState[] = {100, 55, 10};
byte circleStateAnimation[] = {1, 1, 1};
void circleAnimation() {
for (int i = 0; i < 3; i++) {
if (circleState[i] >= 100) {
circleStateAnimation[i] = -1; // dim
}
else if (circleState[i] <= 10) {
circleStateAnimation[i] = 1; // bright
}
circleState[i] += circleStateAnimation[i];
}
for (int i = 0; i < 6; i++) {
SoftPWMSet(innerLedPins[i], circleState[0]);
SoftPWMSet(middleLedPins[i], circleState[1]);
SoftPWMSet(edgeLedPins[i], circleState[2]);
}
delay(5);
}
byte waveState[] = {100, 55, 10, 10, 55, 100};
byte waveStateAnimation[] = {1, 1, 1, -1, -1, -1};
void waveAnimation() {
for (int i = 0; i < 6; i++) {
if (waveState[i] >= 100) {
waveStateAnimation[i] = -1; // dim
}
else if (waveState[i] <= 10) {
waveStateAnimation[i] = 1; // bright
}
waveState[i] += waveStateAnimation[i];
}
for (int i = 0; i < 6; i+=2) {
SoftPWMSet(innerLedPins[i], waveState[0]);
SoftPWMSet(middleLedPins[i], waveState[1]);
SoftPWMSet(edgeLedPins[i], waveState[2]);
SoftPWMSet(innerLedPins[i + 1], waveState[3]);
SoftPWMSet(middleLedPins[i + 1], waveState[4]);
SoftPWMSet(edgeLedPins[i + 1], waveState[5]);
}
delay(10);
}
byte loopCounter = 0;
byte loopState = 150;
void loopAnimation() {
SoftPWMSet(innerLedPins[loopCounter], loopState);
SoftPWMSet(middleLedPins[loopCounter], loopState);
SoftPWMSet(edgeLedPins[loopCounter], loopState);
loopCounter = _nextIndex(loopCounter, 1);
if (loopCounter == 0) {
loopState = (loopState == 150 ? 0 : 150);
}
delay(100);
}
byte slowOnCounter = 0;
byte slowOnState = 150;
void slowOnAnimation() {
byte randomLed = random(0, 18);
if (randomLed < 6) {
SoftPWMSet(innerLedPins[randomLed], slowOnState);
}
else if (randomLed < 12) {
SoftPWMSet(middleLedPins[randomLed - 6], slowOnState);
}
else {
SoftPWMSet(edgeLedPins[randomLed - 12], slowOnState);
}
slowOnCounter ++;
if (slowOnCounter >= 50) {
slowOnCounter = 0;
slowOnState = (slowOnState == 150 ? 0 : 150);
}
delay(50);
}
byte shinyState[] = {0, 100, 0, 100, 0, 100};
byte shinyStateAnimation[] = {1, 1, 1, 1, 1, 1};
byte shinyCounter = 0;
void shinyAnimation() {
for (int i = 0; i < 6; i++) {
if (shinyState[i] >= 100) {
shinyStateAnimation[i] = -1; // dim
}
else if (shinyState[i] <= 0) {
shinyStateAnimation[i] = 1; // bright
}
shinyState[i] += shinyStateAnimation[i];
SoftPWMSet(edgeLedPins[i], shinyState[i]);
}
shinyCounter ++;
if (shinyCounter > 10) {
shinyCounter = 0;
for (byte r = random(1, 3); r > 0; r--) {
byte randomLed = random(0, 12);
if (randomLed < 6) {
SoftPWMSet(innerLedPins[random(0, 6)], 255);
}
else {
SoftPWMSet(middleLedPins[random(0, 6)], 255);
}
}
}
else {
for (int i = 0; i < 6; i++) {
SoftPWMSet(innerLedPins[i], 20);
SoftPWMSet(middleLedPins[i], 20);
}
}
delay(30);
}
byte fadingState[] = {0, 100, 0, 100, 0, 100};
byte fadingStateAnimation[] = {1, 1, 1, 1, 1, 1};
void fadingAnimation() {
for (int i = 0; i < 6; i++) {
if (fadingState[i] >= 100) {
fadingStateAnimation[i] = -1; // dim
}
else if (fadingState[i] <= 0) {
fadingStateAnimation[i] = 1; // bright
}
fadingState[i] += fadingStateAnimation[i];
SoftPWMSet(edgeLedPins[i], fadingState[i]);
SoftPWMSet(middleLedPins[_nextIndex(i, 1)], fadingState[i]);
SoftPWMSet(innerLedPins[i], 50);
}
delay(20);
}
void _fill(byte value) {
for (int i = 0; i < 6; i++) {
SoftPWMSet(edgeLedPins[i], value);
SoftPWMSet(middleLedPins[i], value);
SoftPWMSet(innerLedPins[i], value);
}
}
byte _prevIndex(short index, byte step) {
index -= step;
while (index < 0) {
index += 6;
}
return index;
}
byte _nextIndex(short index, byte step) {
index += step;
while (index > 5) {
index -= 6;
}
return index;
}
