Compare float between limit

Hi,

how to write correctly this condition ?

float temperature;
if (data.temperature >= -15.0 && data.temperature <= 50.0) 
 {Serial.println ("it is Ok"}
else 
 {Serial.println ("Bad value !"}

What’s wrong with how you got it wrote?

Tested and working:

void setup() 
{
  Serial.begin(9600);
}

void loop() 
{
  // The random() function creates a integer value,
  // to get all kind of numbers I use a division.
  float temperature = ((float) random(1, 4000) - 2000.0) / (float) random( 1, 100);

  Serial.print( "The temperatue is ");
  int n = Serial.print( temperature);
  for( int i=n; i<8; i++)
  {
    Serial.print( " ");
  }
  Serial.print( " (");

  // ------------------------------------------------
  
  if( temperature >= -15.0 && temperature <= 50.0)
  {
    Serial.print( "it is Ok");
  }
  else 
  {
    Serial.print( "Bad value !");
  }

  // ------------------------------------------------

  Serial.print( ")");
  Serial.println();
  
  delay( 1000);
}

Thank’s, I have another working solution.

  compareValueFloat = data.temperature * 10;
  compareValue = round(compareValueFloat);
  if (!compareValue >= -150 && !compareValue <= 500)
  {
    Serial.printf("Bad Temperature value: %f\r\n", data.temperature);
    data.temperature = NULL;
  }

Why is there a exclamation before the compareValue in the condition ?

Sorry, I was wrong.
This is my code, but I’m sure there is a more elegant way to write this code, probably as suggested from @Koepel.

void LoRaInterface::sanityCheck(StructData &data)
{
  compareValueFloat = data.temperature * 10;
  compareValue = round(compareValueFloat);
  if (compareValue >= -150 && compareValue <= 500)
  {
  }
  else
  {
    Serial.printf("Bad Temperature value: %f\r\n", data.temperature);
    data.temperature = NULL;
  }

  compareValueFloat = data.humidity * 10;
  compareValue = round(compareValueFloat);
  if (compareValue >= 0 && compareValue <= 1000)
  {
  }
  else
  {
    Serial.printf("Bad Humidity value: %f\r\n", data.humidity);
    data.humidity = NULL;
  }

  compareValueFloat = data.voltage * 10;
  compareValue = round(compareValueFloat);
  if (compareValue >= 0 && compareValue <= 60)
  {
  }
  else
  {
    Serial.printf("Bad Voltage value: %f\r\n", data.voltage);
    data.voltage = NULL;
  }
}

When writing code, it is better to make it as simple and as straightforward as possible.
To check if a float temperature is between certain values or outside a certain range, you can write that directly in code. The ‘C’ and ‘C++’ language is perfect for that.

This is how to put it in code. You may use ‘and’ and ‘or’ instead of && and ||

void LoRaInterface::sanityCheck(StructData &data)
{
  if (data.temperature < -15.0 or data.temperature > 50.0)
  {
    Serial.printf("Bad Temperature value: %f\r\n", data.temperature);
    data.temperature = 0.0;
  }

  ...

Thanks, it work fine. Grazie @Koepel

Are you trying to detect a bad sensor or wrong outside temperature ? What happens if it really gets colder than -15°C or hotter than 50°C (in direct sunlight) ?
I would check for -100 and +500 or so.

This sensor will run on Sicily, Italy, and temperature are never less - 10! :blush:

According to Wikipedia: -15.2°C :cold_face: and 48.5°C :hot_face:

Ok, I will change the limits. Thank’s

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