Using if else statement

Using Arduino Programming Questions
1

Hi trying to get leds to come on at certain temperatures (27c down to 24c then from 24c down to 20c then 20c & below)
I have got the coding this far but seems long way to do this? can I use the IF ELSE statement instead if so please please show me how. Thanks Malcolm

int tempPin = A1;
int led01 = 8;
int led02 = 9;
int led03 = 10;
int tempMax = 28;
int tempMid = 27;
int tempMin = 24;
int temp;

void setup() {
  Serial.begin(9600);
  
  pinMode (led01, OUTPUT);
  pinMode (led02, OUTPUT);
  pinMode (led03, OUTPUT);
  pinMode (tempPin, INPUT);
}
  
void loop() {
  temp = analogRead(tempPin);
  temp = temp * 0.48828125;

  Serial.print("TEMPRATURE = ");
  Serial.print(temp);
  Serial.print("*C");
  Serial.println();
  delay(1000);

  if (temp > tempMax)
  { 
  digitalWrite(led01, HIGH);
  digitalWrite(led02, LOW); 
  digitalWrite(led02, LOW); 
  }
  if (temp < tempMid)
  { 
  digitalWrite(led01, LOW);
  digitalWrite(led02, HIGH); 
  digitalWrite(led02, LOW); 
  }
   if (temp < tempMin)
  { 
  digitalWrite(led01, LOW);
  digitalWrite(led02, LOW);
  digitalWrite(led02, LOW); 
  }

}

Thanks Malcolm

Moderator: added code tags => # button above smiley's

2

Use the code formatting please.

Regarding the if/else, please do some homework first. There are a gazillion posts on the internet about if/else notation and nested if/else for C. A quick google will solve your issue.

3

The series of IF ELSE statements should be

if X > mid // which covers everything above mid

else if x > low // which covers everything between low and mid

else // which covers everything below mid

and you can have as many steps as necessary.

...R

4

something like this, notice how I moved them slightly...

int tempPin = A1;
int led01 = 8;
int led02 = 9;
int led03 = 10;
int tempMax = 28;
int tempMid = 27;
int tempMin = 24;
int temp;

void setup() 
{
  Serial.begin(9600);
  pinMode (led01, OUTPUT);
  pinMode (led02, OUTPUT);
  pinMode (led03, OUTPUT);
  pinMode (tempPin, INPUT);
}

void loop() 
{
  temp = analogRead(tempPin);
  temp = temp * 0.48828125;
  Serial.print("TEMPRATURE = ");
  Serial.print(temp);
  Serial.print("*C");
  Serial.println();
  delay(1000);
  if (temp > tempMax)
  { 
    digitalWrite(led01, HIGH);
    digitalWrite(led02, LOW); 
    digitalWrite(led02, LOW); 
  }
  else if (temp > tempMin)
  { 
    digitalWrite(led01, LOW);
    digitalWrite(led02, LOW);
    digitalWrite(led02, LOW); 
  }
  else
  { 
    digitalWrite(led01, LOW);
    digitalWrite(led02, HIGH); 
    digitalWrite(led02, LOW); 
  }
}
5 
    digitalWrite(led01, LOW);
    digitalWrite(led02, LOW);
    digitalWrite(led02, LOW);

Shouldn't there be an led03 in there (and elsewhere) ?

This looks like the copy/paste/distracted/forget to revise pasted text syndrome. - BTDTGTTS

To me the program looks a little odd with temp being an int which is multiplied by 0.48828125 with the result assigned back to temp.