c++ - 模拟读数的计算出现错误

Question

我正在为 Arduino Uno 编程，但我陷入了一个 while 循环，因为我无法对某些传感器值进行计算。当我读取我的四个传感器值并比较前两个与后两个的比率时，无论值是什么，我都会得到 0.00。这是我的代码:

while ( ( (frontleft + frontright) / (backleft + backright) <= 0.8 ) || ( (frontleft + frontright) / (backleft + backright) > 1.2) ) {
    if (backleft + backright > frontleft + frontright) {
      myStepper2.step(10);
    }
    if (backleft + backright < frontleft + frontright) {
      myStepper2.step(-10);
    }
    int backleft = analogRead(A0);
    int backright = analogRead(A1);
    int frontleft = analogRead(A2);
    int frontright = analogRead(A3);   

    Serial.print("Backleft Reading: ");
    Serial.println(backleft);
    Serial.print("\n");
    Serial.print("BackRight Reading: ");
    Serial.println(backright);
    Serial.print("\n");
    Serial.print("Frontleft Reading: ");
    Serial.println(frontleft);
    Serial.print("\n");
    Serial.print("Frontright Reading: ");
    Serial.println(frontright);
    Serial.print("\n");
    float ratio = (frontleft + frontright) / (backleft + backright);
    float math = (5 + 6) / (4 + 5);
    Serial.print("Math: ");
    Serial.println(math);
    Serial.print("Ratio: ");
    Serial.println(ratio);
    Serial.print("\n");
    delay(500);

  }    

我正在获取传感器 backleft、backright、frontleft 和 frontright 的值，但“ratio ' 总是出现 0.00。因此，我相信我陷入了循环。这里发生了什么？

此外，为了检查，我添加了“数学” float 作为快速计算，但我在串行监视器中得到的值为 1.00。为什么？应该是 1.222。

Answer 1

尝试

float ratio = (frontleft + frontright) / float((backleft + backright));
while ( ratio <= 0.8  ||  ratio > 1.2)  {
    //do your thing here

    ratio = (frontleft + frontright) / float((backleft + backright));
}

然后当你尝试打印时

Serial.println(ratio, 4) //prints four decimal places