跪求c语言大神给解答一下这个程序每句的意思！！臣妾看不懂啊！这是电路相关的。。

Question

#define ANALOG_PIN 1
#define BUTTON_PIN 8
#define LED_PIN 5

#define LED_SCALE 2.6
#define MIN_LED 150
#define LED_OFFSET 300
#define DEBOUNCE_DELAY 10

int lightLevel = 0;
bool ledOn = false;

/**
* Setup the serial communication and pin modes.
*/
void setup()
{
Serial.begin(9600);

pinMode(BUTTON_PIN, INPUT);
pinMode(LED_PIN, OUTPUT);

// DDRD = (DDRD | B00000100) & B11110111; // e.g. for BUTTON_PIN = 3, LED_PIN = 2
}

/**
* Read and debounce the input from the button.
*/
bool buttonPressed()
{
int button = digitalRead(BUTTON_PIN);
if(button == LOW)
{
while(button == LOW)
{
delay(1);
button = digitalRead(BUTTON_PIN);
}
delay(DEBOUNCE_DELAY);
return true;
}

return false;
}

/**
* Check the light level, make sure the light level is with range,
* set the LED brightness, if the button is pressed toggle the LED.
*/
void loop()
{

if(buttonPressed())
{
ledOn = !ledOn;
Serial.print("LED is now");
Serial.print(ledOn ? " on" : " off");
}

if(ledOn)
{
lightLevel = (analogRead(ANALOG_PIN) - LED_OFFSET)*LED_SCALE; // 10 bits

if(lightLevel > 1023)
lightLevel = 1023;
if(lightLevel < MIN_LED)
lightLevel = MIN_LED;

analogWrite(LED_PIN, lightLevel >> 2); // 8 bits

Serial.println(lightLevel);
}
else
{
digitalWrite(LED_PIN, LOW);
}

delay(100);
}

Answer 1

#define ANALOG_PIN 1

#define BUTTON_PIN 8

#define LED_PIN 5


#define LED_SCALE 2.6

#define MIN_LED 150

#define LED_OFFSET 300

#define DEBOUNCE_DELAY 10


int lightLevel = 0;

bool ledOn = false;


/**

 * Setup the serial communication and pin modes.

 */

void setup() 

{

  Serial.begin(9600);//设置串口波特率9600


  pinMode(BUTTON_PIN, INPUT);//引脚8为输入模式

  pinMode(LED_PIN, OUTPUT);//引脚5为输出模式

// DDRD = (DDRD | B00000100) & B11110111; //e.g.for BUTTON_PIN = 3,LED_PIN = 2

}


/**

 * Read and debounce the input from the button.

 */

bool buttonPressed() 

{

  int button = digitalRead(BUTTON_PIN);//读取引脚8的电平

  if(button == LOW)//如果是高电平

  {

    while(button == LOW)

    {

      delay(1);//延时

      button = digitalRead(BUTTON_PIN);

    }

    delay(DEBOUNCE_DELAY);//延时

    return true;

  }


  return false;

}


/**

 * Check the light level, make sure the light level is with range, 

 * set the LED brightness, if the button is pressed toggle the LED.

 */

void loop() 

{


  if(buttonPressed()) //引脚8为高电平时,就是按下按键

  {

    ledOn = !ledOn;//反转

    Serial.print("LED is now");//串口输出信息

    Serial.print(ledOn ? " on" : " off");

  }


  if(ledOn) //如果为真

  {
//下面应该是PWM调节灯的光暗度

    lightLevel = (analogRead(ANALOG_PIN) - LED_OFFSET)*LED_SCALE; // 10 bits


    if(lightLevel > 1023)

      lightLevel = 1023;

    if(lightLevel < MIN_LED)

      lightLevel = MIN_LED;


    analogWrite(LED_PIN, lightLevel >> 2); // 8 bits


    Serial.println(lightLevel);//串口输出相关信息

  }

  else

  {

    digitalWrite(LED_PIN, LOW);//LED引脚输出高电平

  }


  delay(100);

}