即使 digitalRead 低，LED 也会保持亮起

Question

我只是在创建一个简单的基本程序，但我不知道出了什么问题。

我已经将三个引脚设置为输出，三个引脚设置为输入。当这三个引脚 digitalRead == HIGH 时，它们会将 LED 设置为 HIGH，但我的 LED 始终保持高电平。

这是我的 Arduino 代码：

int LED_Low = 4; // Red LED
int LED_Avg = 3; // Yellow LED
int LED_High = 2; // Green Led

int WaterLow = 7;
int WaterAvg = 8;
int WaterHigh = 9;


void setup() {
  // Put your setup code here, to run once:
  pinMode(LED_Low,  OUTPUT);
  pinMode(LED_Avg,  OUTPUT);
  pinMode(LED_High, OUTPUT);

  pinMode(WaterLow,  INPUT);
  pinMode(WaterAvg,  INPUT);
  pinMode(WaterHigh, INPUT);
}

void check(){
    if(digitalRead(WaterLow) == HIGH){ // If Water level is low
        digitalWrite(ledLow, HIGH); // Turn on red LED indication water level is low
    }
    else{
        digitalWrite(ledLow, LOW);
    }
    if(digitalRead(WaterAvg) == HIGH){ // If water level is medium
        digitalWrite(ledAvg, HIGH); // Turn on yellow LED indicating water level is average
    }
    else{
        digitalWrite(ledAvg, LOW);
    }
    if(digitalRead(WaterHigh) == HIGH){ //
        digitalWrite(ledHigh, HIGH); //
    }
    else{
        digitalWrite(ledHigh, LOW);
    }
}

void loop() {
    // Put your main code here, to run repeatedly:
    check();
}

在上图中，我在引脚 2、3 和 4 上连接了 1.5 kΩ 电阻器，并在引脚 7、8 和 9 中连接了三根电线，它们将接收来自 5 伏引脚的输入并打开 LED .因此，5伏引脚连接到电源总线上的正极端子并串联9.1 * 2个电阻，然后该线连接引脚2、3和4。

Answer 1

我发现了问题。我的代码没问题。这是我的电路。

我声明接收输入的引脚没有接地。

Answer 2

你可以在两个案例的帮助下做到这一点

定义延迟

if (digitalRead(WaterLow) == HIGH) // If Water level is low
{
    digitalWrite(ledLow, HIGH); // Turn red LED indication water level is low
    delay(2000);
}
else
{
    digitalWrite(ledLow, LOW);
}

设置这样的条件

int stateled = LOW;
int previous = LOW;
long time = 0;
long debounce = 200;

void loop()
{
    stateButton = digitalRead(WaterLow);
    if (stateButton == HIGH && previous == LOW && millis() - time > debounce)
    {
        if(stateLED == HIGH)
        {
            stateLED = LOW;
        }
        else
        {
            stateLED = HIGH;
        }
        time = millis();
    }
    digitalWrite(ledlow, stateLED);
    previous == stateButton;
}

即使 digitalRead 低，LED 也会保持亮起

LED stays on even when digitalRead is low

arduino

arduino-uno