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#include <Servo.h>
Servo myservo;

int ledPin = 12;
int pirPin = 13;
int pirStat = 0;
int pos = 0;

void setup() {
pinMode (ledPin,OUTPUT);
pinMode (pirPin, INPUT);
myservo.attach(9);
Serial.begin(9600);
myservo.write(pos);
}

void loop() {

  
   pirStat = digitalRead(pirPin);

if (pirStat == HIGH);
    digitalWrite (ledPin, HIGH);
    Serial.println("Motion Detected");
   for (pos = 0; pos<= 180; pos += 1) {
     myservo.write (pos);
     delay(20);
   }
   digitalWrite(ledPin, LOW);
     for (pos = 180; pos >= 0; pos -= 1){
     myservo.write(pos);
    delay (120);
  }
} 
else{  
}
}


What I have tried:

I have set the commas and brackets but error is same. kindly guide me to resolve or type the correct code for for my solution. its my lab project
Posted
Updated 21-Jan-23 0:39am

Look at this line:
C++
if (pirStat == HIGH);

An if statement should be followed by a single expression, or the start of a block, not a semi-colon:
C++
if (pirStat == HIGH)
{
 
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Comments
CPallini 21-Jan-23 7:04am    
5.
Richard MacCutchan 21-Jan-23 10:33am    
Thanks.
Andre Oosthuizen 21-Jan-23 10:21am    
Same here - 5
Richard MacCutchan 21-Jan-23 10:33am    
Thanks.
Indent your code consistently and it becomes obvious:
C++
void loop() 
    {
    pirStat = digitalRead(pirPin);
    if (pirStat == HIGH);
    digitalWrite (ledPin, HIGH);
    Serial.println("Motion Detected");
    for (pos = 0; pos<= 180; pos += 1) 
        {
        myservo.write (pos);
        delay(20);
        }
    digitalWrite(ledPin, LOW);
    for (pos = 180; pos >= 0; pos -= 1)
        {
        myservo.write(pos);
        delay (120);
        }
    } 
    else
        {  
        }
    }
You have a semicolon terminating your if:
if (pirStat == HIGH);
So the close curly bracket before the else terminates the function.
Try this:
C++
void loop() 
    {
    pirStat = digitalRead(pirPin);
    if (pirStat == HIGH)
        {
        digitalWrite (ledPin, HIGH);
        Serial.println("Motion Detected");
        for (pos = 0; pos<= 180; pos += 1) 
            {
            myservo.write (pos);
            delay(20);
            }
        digitalWrite(ledPin, LOW);
        for (pos = 180; pos >= 0; pos -= 1)
            {
            myservo.write(pos);
            delay (120);
            }
        } 
    else
        {  
        }
    }
And now the brackets all match up.

It doesn't matter which indentation and bracket placement scheme you use - though some are better than others - as long as you are consistent. Random indentation is useless though.

You should expect to get syntax errors every day, probably many times a day while you are coding - we all do regardless of how much experience we have! Sometimes, we misspell a variable, or a keyword; sometimes we forget to close a string or a code block. Sometimes the cat walks over your keyboard and types something really weird. Sometimes we just forget how many parameters a method call needs.

We all make mistakes.

And because we all do it, we all have to fix syntax errors - and it's a lot quicker to learn how and fix them yourself than to wait for someone else to fix them for you! So invest a little time in learning how to read error messages, and how to interpret your code as written in the light of what the compiler is telling you is wrong - it really is trying to be helpful!

So read this: How to Write Code to Solve a Problem, A Beginner's Guide Part 2: Syntax Errors[^] - it should help you next time you get a compilation error!
 
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Comments
CPallini 21-Jan-23 7:04am    
5.
Andre Oosthuizen 21-Jan-23 10:21am    
Same here - 5, more in detail but 5 is the limit :)
Richard MacCutchan 21-Jan-23 10:32am    
You do know that his cat writes all the details. :)
OriginalGriff 21-Jan-23 10:36am    
Damn! My secret is out. Meow. :D
Andre Oosthuizen 21-Jan-23 10:59am    
Hahahaha.

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