具有最大亮度的快速LED呼吸效果

Question

我有问题。我正在使用Arduino控制WS2812B，但是呼吸效果有问题。我在看起来像这样的代码中创建了一个类：

String breathDirection = "Down";

class Nanohex
{
  private:
    CRGB primary;
    uint16_t mode;
    uint8_t hueRandomness;
    uint8_t brightness;
    uint8_t selectedShape;

  public:
    Nanohex() : mode(1),
                primary(CRGB(0, 0, 0)),
                hueRandomness(50),
                brightness(0)
    {
        FastLED.addLeds<WS2812B, LED_PIN, BRG>(leds, TOTAL_LEDS);
    }

    void mode_breath()
    {
      if (brightness != 0)
      {
          fill_solid(leds, TOTAL_LEDS, primary);
          float currentBrightness = FastLED.getBrightness();

          if (currentBrightness <= 0)
          {
              breathDirection = "Up";
          } 
          else if (currentBrightness >= brightness)
          {
              breathDirection = "Down";
          }

          float brightnessCorrection = brightness / 200;
          if (breathDirection == "Down")
          {
              currentBrightness = currentBrightness - brightnessCorrection;
              FastLED.setBrightness(currentBrightness);
          }
          else if (breathDirection == "Up")
          {
              currentBrightness = currentBrightness + brightnessCorrection;
              FastLED.setBrightness(currentBrightness);
          }
       }
    }

/* MORE CODE BELOW, BUT NOT RELEVANT */

现在呼吸效果仅在brightness变量设置为200时起作用。如果我将其设置为200以下的其他值，则currentBrightness会一遍又一遍地返回相同的值，而brightnessDirection返回Down 。

这里出了什么问题？

Answer 1

对于低于200的值，此表达式

float brightnessCorrection = brightness / 200;

由于integer division的行为，总是被评估为0。

尝试改成类似的东西>>

float brightnessCorrection = static_cast<float>(brightness) / 200;