Grove - LED Bar

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LED Bar,常见于音量显示,是模拟传感器的一个常用显示元件。你可以用一排分立的LED灯来制作这个效果,也可以使用我们这里提到的元件。

通过我们这里讲到的程序,我们将模拟输入的传感器值分布到输出的范围,然后通过一个条件结构函数,控制LED bar上的显示效果。

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Arduino LED Bar 220Ω电阻 面包板 面包线


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 LED bar graph

 Turns on a series of LEDs based on the value of an analog sensor.
 This is a simple way to make a bar graph display. Though this graph
 uses 10 LEDs, you can use any number by changing the LED count
 and the pins in the array.
 This method can be used to control any series of digital outputs that
 depends on an analog input.

 The circuit:
  * LEDs from pins 2 through 11 to ground

created 4 Sep 2010
by Tom Igoe 
This example code is in the public domain.

// these constants won't change: const int analogPin = A0; // the pin that the potentiometer is attached to const int ledCount = 10; // the number of LEDs in the bar graph

int ledPins[] = {

 2, 3, 4, 5, 6, 7,8,9,10,11 };   // an array of pin numbers to which LEDs are attached

void setup() {

 // loop over the pin array and set them all to output:
 for (int thisLed = 0; thisLed < ledCount; thisLed++) {
   pinMode(ledPins[thisLed], OUTPUT); 


void loop() {

 // read the potentiometer:
 int sensorReading = analogRead(analogPin);
 // map the result to a range from 0 to the number of LEDs:
 int ledLevel = map(sensorReading, 0, 1023, 0, ledCount);
 // loop over the LED array:
 for (int thisLed = 0; thisLed < ledCount; thisLed++) {
   // if the array element's index is less than ledLevel,
   // turn the pin for this element on:
   if (thisLed < ledLevel) {
     digitalWrite(ledPins[thisLed], HIGH);
   // turn off all pins higher than the ledLevel:
   else {
     digitalWrite(ledPins[thisLed], LOW);