Week 9 – Assignment – Caution Coaster

For this assignment we were required to apply the concepts and components used so far to create a project involving an analog sensor, a digital sensor and two LEDs. I decided to explore the functioning of the TMP36 Temperature sensor and have used it as the analog sensor to develop a simple temperature detection model that may be employed in beverage holders to warn the people of the temperature of the contents of the glass.

Using the RGB LED, I have depicted temperature ranges from hot to cold by changing the colors from red to green to blue. Apart from this I have used a switch along with a yellow LED which may be turned on or off. As the program runs, the corresponding temperature value is printed in the Serial Monitor.

I have demonstrated the working of this circuit using glasses containing water of different temperatures ranging from ice cold to boiling hot and was able to achieve the desired color code.

Assignment Video

I particularly enjoyed figuring out the connections and coding for the temperature sensor through a video and the datasheet provided.

Overall, I believe the assignment helped me delve deeper into creating simple circuits and the commands of Arduino IDE.

int RED=9;
int GREEN=10;
int BLUE=11;
int PIN=A0;
void setup() {
  Serial.begin(9600);
  pinMode(RED,OUTPUT);
  pinMode(BLUE,OUTPUT);
  pinMode(GREEN,OUTPUT);
}

void loop() {
  int sensorValue=analogRead(PIN);
  delay(200); //delays the frequency of temperature readings
  float mv = sensorValue*4.9; //converts the analog input into mV
  float temp = (mv-500)/10; //calculates the final temperature value
  Serial.print("Temperature: ");
  Serial.print((mv-500)/10);
  Serial.print("°C\n");
  if (temp>27){
    digitalWrite(RED,HIGH);
    digitalWrite(GREEN,LOW);
    digitalWrite(BLUE,LOW);
  }
  else if (temp>21){
    digitalWrite(GREEN,HIGH);
    digitalWrite(RED,LOW);
    digitalWrite(BLUE,LOW);
  }
  else if (temp>16){
    digitalWrite(BLUE,HIGH);
    digitalWrite(GREEN,LOW);
    digitalWrite(RED,LOW);
  }
  
}