Sensor Serial Monitor

[rian2001]

hey, i got problem in my arduino code, when i push the button on, it just appear serial monitor for just 3 seconds, how i can make it still update until i push the button off? thanks.

const int buttonON 	= 7;
const int buttonOFF = 4;	
const int ledPin 	= 8;  
int 	  sensorPin = A1; 

int buttonState = 0;     

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonON, INPUT);
  pinMode(buttonOFF,INPUT);
  Serial.begin(9600);
}

void loop() {
   int reading = analogRead(sensorPin);  
   float voltage = reading * 5.0;
   voltage /= 1024.0; 
   float temperatureC = (voltage - 0.5) * 100 ;  
   
   buttonState = digitalRead(buttonON);
  if (buttonState == HIGH) {
    digitalWrite(ledPin, HIGH);
    Serial.print(temperatureC, HIGH); 
    Serial.println(" C");
    if	(temperatureC>=70);
    	digitalWrite(ledPin, LOW);
  }   
  
  	buttonState = digitalRead(buttonOFF);
   	if (buttonState == HIGH) {
    digitalWrite(ledPin, LOW);
  
  }
}

[sterretje]

@rian2001, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advise on) your project See About the Installation & Troubleshooting category.

Please edit your post, select all code and click the </> button to apply so-called code tags and next save your post. It makes it easier to read, easier to copy and prevents the forum software from incorrect interpretation of the code.

[sterretje]

Your LED does not have a current limiting resistor.

@rian2001

it just appear serial monitor for just 3 seconds

I don't see a reason for the 3 seconds; is that the time that you keep the buttonOn pressed?

If so, set a variable when you detect that the buttonOn is pressed and clear the variable when the buttonOff is pressed.

void loop()
{
  static bool showReading = false;  

  int reading = analogRead(sensorPin);
  float voltage = reading * 5.0;
  voltage /= 1024.0;
  float temperatureC = (voltage - 0.5) * 100 ;

  buttonState = digitalRead(buttonON);
  if (buttonState == HIGH)
  {
    showReading = true;
  }

  buttonState = digitalRead(buttonOFF);
  if (buttonState == HIGH)
  {
    showReading = false;
  }

  if(showReading == true)
  {
    digitalWrite(ledPin, HIGH);
    Serial.print(temperatureC, HIGH);
    Serial.println(" C");
    if (temperatureC >= 70);
    digitalWrite(ledPin, LOW);    
  }
  else
  {
    digitalWrite(ledPin, LOW);
  }
}

[rian2001]

do u have suggest what should i do to make the serial monitor keep updating?

[sterretje]

Did you look at the code in post #3; something you don't understand?

Did you try it? If so, what happened; how did the expected behaviour differ from what you need?

[PaulRB]

    if	(temperatureC>=70);
    	digitalWrite(ledPin, LOW);

You might want to fix that.