c++ - C 编译错误 : stray '\200' in program and expected ')' before numeric constant

Question

我复制了这个程序，但在使用 void downFrequency 函数时遇到了问题(我认为)。

这是给 Arduino Uno 的.以下是编译器错误:

为“Arduino Uno”编译“MY_dds”

MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : stray '\342' in program
MY_dds.ino : stray '\200' in program
MY_dds.ino : stray '\223' in program
MY_dds.ino : : In function 'void downFrequency()':
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
MY_dds.ino : expected `)' before numeric constant
Error compiling

程序如下:

#include <stdio.h>
#include <dds.h>
#include <LiquidCrystal.h>

#define RESET 13
#define data_pin 12
#define load_pin A5
#define clock_pin A4
#define clock_hz 120000000LL
#define calibrationValue -0.0400000 // This is a value we change to calibrate
                                    // our particular chip more accurately
#define buttonPin A0

// chip, data_pin, load_pin, clock_pin, clock_hz
dds ddschip(DDS9850, data_pin, load_pin,  // Set my dds up with 120 MHz
            clock_pin, clock_hz);         // onboard crystal

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// Some variables to use in our program
long toFrequency = 14070000;
long currentFrequency;
long maxFrequency = 40000000;
long minFrequency = 0;
int incrementNumber = 6;
int maxprogramnumber = 6; // Don't forget to increase the menu numbers here!!
int programnumber = 1;

void setup()
{
  Serial.begin(9600);
  Serial.println("Beginning Setup");

  // Set up the LCD’s number of columns and rows:
  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T.Robb V0.1b "); // Print a little message
  lcd.setCursor(0, 1);
  lcd.print(" DDS Sine wave ");
  delay(2000);

  // Set up pins
  pinMode(RESET, OUTPUT);
  pinMode(data_pin, OUTPUT);
  pinMode(load_pin, OUTPUT);
  pinMode(clock_pin, OUTPUT);
  pinMode(buttonPin, INPUT);
  digitalWrite(buttonPin, HIGH);

  ddschip.calibrate(calibrationValue); // This is a value we change to calibrate
                                       // our particular chip more accurately
  ddschip.setfrequency(toFrequency);
  lcd.clear();
}

void loop()
{
  if(toFrequency >= maxFrequency)
  {
    (toFrequency = maxFrequency);
  }

  if(toFrequency <= minFrequency)
  {
    (toFrequency = minFrequency);
  }

  ddschip.setfrequency(toFrequency);
  currentFrequency = toFrequency;

  switch(incrementNumber)
  {
    case 0:
      Serial.println("increment amount is 1 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 1 Hz");
      break;

    case 1:
      Serial.println("increment amount is 10 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 10 Hz ");
      break;

    case 2:
      Serial.println("increment amount is 100 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 100 Hz ");
      break;

    case 3:
      Serial.println("increment amount is 1 000 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 1 kHz");
      break;

    case 4:
      Serial.println("increment amount is 10 000 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 10 kHz");
      break;

    case 5:
      Serial.println("increment amount is 100 000 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 100 kHz");
      break;

    case 6:
      Serial.println("increment amount is 1 000 000hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 1 MHz");
      break;

    default:
      Serial.println("increment amount is 100 Hz");
      lcd.setCursor(0, 0);
      lcd.print("Change By 100 Hz ");
      break;
  }

  lcd.setCursor(0, 1);
  lcd.print("Freq is "); // Print to LCD
  lcd.setCursor(8, 1);
  lcd.print(currentFrequency);

  Serial.println(incrementNumber); // Temporary for debugging delete me

  Serial.print("Current frequency is set to: ");
  Serial.println(currentFrequency);

  while((analogRead(buttonPin))>=1000) // Do nothing while no buttons pressed to chill out
  {
  }

  delay(5);
  if (analogRead(buttonPin)>=100 && analogRead(buttonPin) <= 200) // We have pushed up
  {
    upFrequency();
    delay(300);
  }

  if(analogRead(buttonPin)>=200 && analogRead(buttonPin) <= 400) // We have pushed down
  {
    downFrequency();
    delay(300);
  }

  if ((analogRead(buttonPin)) <= 50) // We have pushed right
  {
    incrementNumber++;
    delay(300);
  }

  if(analogRead(buttonPin) >= 400 && analogRead(buttonPin)<=600) // We have pushed left
  {
    incrementNumber–;
    delay(300);
  }

  if(incrementNumber > 6) // This is where the menu goes around and around
  {
    incrementNumber = 0;
  }
  if(incrementNumber < 0)
  {
    incrementNumber = 6;
  }

  delay(100);
  lcd.clear();
}

void upFrequency()
{
  Serial.println("Going UP Frequency");
  switch(incrementNumber)
  {
    case 0:
      toFrequency = (toFrequency + 1);
      break;

    case 1:
      toFrequency = (toFrequency + 10);
      break;

    case 2:
      toFrequency = (toFrequency + 100);
      break;

    case 3:
      toFrequency = (toFrequency + 1000);
      break;

    case 4:
      toFrequency = (toFrequency + 10000);
      break;

    case 5:
      toFrequency = (toFrequency + 100000);
      break;

    case 6:
      toFrequency = (toFrequency + 1000000);
      break;

    default:
      toFrequency = (toFrequency + 10);
      break;
  }

}


void downFrequency()
{
  Serial.println("Going DOWN Frequency");
  switch(incrementNumber)
  {
    case 0:
      toFrequency = (toFrequency – 1);
      break;

    case 1:
      toFrequency = (toFrequency – 10);
      break;

    case 2:
      toFrequency = (toFrequency – 100);
      break;

    case 3:
      toFrequency = (toFrequency – 1000);
      break;

    case 4:
      toFrequency = (toFrequency – 10000);
      break;

    case 5:
      toFrequency = (toFrequency – 100000);
      break;

    case 6:
     toFrequency = (toFrequency – 1000000);
     break;

    default:
      toFrequency = (toFrequency – 10);
      break;
  }

}

Answer 1

在 downFrequency 函数中，您以某种方式结束了“破折号”字符，而不是正常的减号。

确保您使用的是文本编辑器，而不是文字处理器；对于其中的每一个:

toFrequency = (toFrequency – 1);
                           ^

删除标记的字符，然后重新键入一个正常的减号。

(如果您对血淋淋的细节感兴趣，“破折号”字符是 Unicode 2013 ，以 UTF-8 编码为三个字节，八进制值为 324,200,223，这就是您在错误消息中看到这些数字的原因。)