Unknown problem with Love-o-Meter from projects book

Projects Programming
1

Well I ran through the project just fine, my LED's light up as the sensor gets warmer... However when I go into the serial monitor for some reason it is not printing out the temperature

const int sensorPin = A0;
const float baselineTemp = 20.0;
void setup() {
  // put your setup code here, to run once:
 Serial.begin(9600);
for (int pinNumber = 2; pinNumber<5; pinNumber++){
 pinMode (pinNumber , OUTPUT);
 digitalWrite (pinNumber , LOW);
 } 
}

void loop() {
  // put your main code here, to run repeatedly:
  int sensorVal = analogRead(sensorPin);
  Serial.print("Sensor Value: ");
  Serial.print(sensorVal);
  float voltage = (sensorVal/1024.0)*5.0;// new value represents pins voltage
  Serial.print(" , Volts: ");
  Serial.print(voltage);
  float temperature = (voltage - .5)*100;
  Serial.println(temperature);
    if(temperature<baselineTemp){
      digitalWrite(2,LOW);
      digitalWrite(3,LOW);
      digitalWrite(4,LOW);
    }else if (temperature >=baselineTemp && temperature< baselineTemp+4){
      digitalWrite(2,HIGH);
      digitalWrite(3,LOW);
      digitalWrite(4,LOW);
    }else if (temperature >= baselineTemp +4 && temperature<baselineTemp+6){
      digitalWrite(2,HIGH);
      digitalWrite(3,HIGH);
      digitalWrite(4,LOW);
    }else if (temperature >= baselineTemp +6){
      digitalWrite(2,HIGH);
      digitalWrite(3,HIGH);
      digitalWrite(4,HIGH);
    }
  delay(1);
}

Other than that everything seems to be working fine.
also, on a side note; what does pinNumber++ do?
the book didn't really explain it and I had a hard time finding out on google so far.

sorry if this question has been asked a million times, I'm new to the forums as well as the Arduino and programming in general. Any help will be greatly appreciated, Thank you!

2

I can't help with your Serial issue.

pinNumber++ increments the value in the variable pinNumber by one.

It's short for

pinNumber =  pinNumber + 1;
OR
pinNumber += 1;

Note:
incrementing pointers this way will increment them by the size of the (base) type (e.g. a pointer to an int will increment the pointer value by sizeof(int) so it points to the next integer.

1 Like
3

Does it print anything at all on the screen?

4

You need to work on your code layout. At the beginning you have a lot of white space. Too much , in fact.

Later,youdon'thavenearenough.

Consistency is a good thing.

NOTHING follows a } on the same line, in ANY recognized coding style.

5

Check the baud that Serial monitor is set to (drop down menu, lower right of serial monitor window). The program is set to 9600 (Serial.begin(9600) in setup()). I tried your code and it compiles and prints to serial monitor just fine.

6

thank you! you guys are very helpful!