Having a seriail.print only show up once after if function has run

[morgan_reid03]

Im coding a parachute to deploy at a certain altitude using a pressure sensor, the code for that has all been figured out, however i want a message to be displayed after the parachute has deployed however with the code
if (temperature >= 28 ){servo.write(90);
Serial.print ("Prachute Deployed");
}
it will constantly show the "Parachute deployed" message at a rate of twice per second, and i was wondering if there was a way to prevent this and for it to only show once
(the temperature command is only for testing the final product will use temperature)

[LarryD]

printFlag = true;

. . . 

if (temperature >= 28 )
{
servo.write(90);

  if (printFlag == true)
   {
      Serial.print ("Prachute Deployed");
      printFlag = false;
   }
}

[johnwasser]

@morgan_reid03

if (temperature >= 28 ){servo.write(90);
Serial.print ("Prachute Deployed");
}

Quick and dirty:

  if (temperature >= 28 && servo.read() != 90)
  {
    servo.write(90);
    Serial.print ("Prachute Deployed");
  }

Note: servoRead() just returns the last position you set the servo to. It does not return the actual position of the servo.

[morgan_reid03]

Where does the first line "printFlag = true;" go in the code?

[LarryD]

Make it global i.e. place it before setup()

[morgan_reid03]

i get this error message
Arduino: 1.8.12 (Windows 10), Board: "Arduino Uno"

Temperature_and_pressure:19:1: error: 'printFlag' does not name a type; did you mean 'printf_P'?

printFlag = true;

^~~~~~~~~

printf_P

C:\Users\Morgan\Documents\Arduino\Temperature_and_pressure\Temperature_and_pressure.ino: In function 'void loop()':

Temperature_and_pressure:49:1: error: 'printFlag' was not declared in this scope

printFlag = true;

^~~~~~~~~

C:\Users\Morgan\Documents\Arduino\Temperature_and_pressure\Temperature_and_pressure.ino:49:1: note: suggested alternative: 'printf_P'

printFlag = true;

^~~~~~~~~

printf_P

Temperature_and_pressure:58:1: error: expected '}' at end of input

}

^

exit status 1
'printFlag' does not name a type; did you mean 'printf_P'?

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

[LarryD]

@LarryD

printFlag = true;

Try:

bool printFlag = true;