arduino-fan-speed-controlled-temperature

arduino-fan-speed-controlled-temperature

1. #include <LiquidCrystal.h>

1. //source: http://www.electroschematics.com/9540/arduino-fan-speed-controlled-temperature/

1. LiquidCrystal lcd(7,6,5,4,3,2);

1. int tempPin = A1; // the output pin of LM35

1. int fan = 11; // the pin where fan is

1. int led = 8; // led pin

1. int temp;

1. int tempMin = 30; // the temperature to start the fan

1. int tempMax = 70; // the maximum temperature when fan is at 100%

1. int fanSpeed;

1. int fanLCD;

1.  

1. void setup() {

1. pinMode(fan, OUTPUT);

1. pinMode(led, OUTPUT);

1. pinMode(tempPin, INPUT);

1. lcd.begin(16,2);

1. }

1.  

1. void loop() {

1. temp = readTemp(); // get the temperature

1. if(temp < tempMin) { // if temp is lower than minimum temp

1. fanSpeed = 0; // fan is not spinning

1. digitalWrite(fan, LOW);

1. }

1. if((temp >= tempMin) && (temp <= tempMax)) { // if temperature is higher than minimum temp

1. fanSpeed = map(temp, tempMin, tempMax, 32, 255); // the actual speed of fan

1. fanLCD = map(temp, tempMin, tempMax, 0, 100); // speed of fan to display on LCD

1. analogWrite(fan, fanSpeed); // spin the fan at the fanSpeed speed

1. }

1. if(temp > tempMax) { // if temp is higher than tempMax

1. digitalWrite(led, HIGH); // turn on led

1. } else { // else turn of led

1. digitalWrite(led, LOW);

1. }

1. lcd.print("TEMP: ");

1. lcd.print(temp); // display the temperature

1. lcd.print("C ");

1. lcd.setCursor(0,1); // move cursor to next line

1. lcd.print("FANS: ");

1. lcd.print(fanLCD); // display the fan speed

1. lcd.print("%");

1. delay(200);

1. lcd.clear();

1. }

1.  

1. int readTemp() { // get the temperature and convert it to celsius

1. temp = analogRead(tempPin);

1. return temp * 0.48828125;

1. }