thermal-pwm-fan-controller.ino

#include <OneWire.h>
#include <DallasTemperature.h>
#include <FanController.h>

#define ONE_WIRE_BUS 7
#define SENSOR_PIN 2
#define SENSOR_THRESHOLD 1000
#define PWM_PIN 9
#define GATE_PIN 4

FanController fan(SENSOR_PIN, SENSOR_THRESHOLD, PWM_PIN);

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

byte dutyCycle;
int realTemp;
int limitTemp;

void setup() {
  fan.begin();
  pinMode(GATE_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // Get temp from sensor
  sensors.requestTemperatures();
  realTemp = sensors.getTempFByIndex(0);
  Serial.print("Temp F: ");
  Serial.println(realTemp);

  // Set limited temp range for dutyCycle
  limitTemp = min(max(realTemp, 90), 130);
  Serial.print("limit temp: ");
  Serial.println(limitTemp);
    
  // Set temp scale for PWM duty cycle
  dutyCycle = map(limitTemp, 90, 130, 0, 100);
  
  Serial.print("Current speed: ");
  // Send the command to get RPM
  unsigned int rpms = fan.getSpeed(); 
  Serial.print(rpms);
  Serial.println(" RPM");

  // Print obtained value
  Serial.print("Setting duty cycle: ");
  Serial.println(dutyCycle, DEC);

  // Set fan duty cycle
  fan.setDutyCycle(dutyCycle);

  // Get duty cycle
  byte dutyCycle = fan.getDutyCycle();
  Serial.print("Duty cycle: ");
  Serial.println(dutyCycle, DEC);

  // Control MOSFET gate to fan.
  if (dutyCycle > 0) {
    digitalWrite(GATE_PIN, HIGH);
  }
  else {
    // Cuts fan power when PWM is 0%.
    digitalWrite(GATE_PIN, LOW);
  }
  
  delay(500);
}