¶ Schéma
¶ Brochage des ventilateurs
!
¶ Code
#define FAN_WIRES 4
#define PWM_PIN 3
#define SENSOR_PIN 2
#if FAN_WIRES == 4
volatile unsigned int revs;
#endif
void setup() {
Serial.begin(115200);
Serial.println("FAN CONTROL");
// prescaller for 31.372KHz
TCCR2B &= B11111000;
TCCR2B |= (0 << CS22) | (0 << CS21) | (1 << CS20);
digitalWrite(PWM_PIN, LOW);
pinMode(PWM_PIN, OUTPUT);
#if FAN_WIRES == 4
attachInterrupt(digitalPinToInterrupt(SENSOR_PIN), interruptHandler, FALLING);
#endif
}
void loop()
{
int pwm, pwmGpio;
for (pwm = 0 ; pwm <= 100 ; pwm += 10) {
Serial.print(pwm);
Serial.print("%: (");
pwmGpio = pwm * 2.5;
Serial.print(pwmGpio);
Serial.print(") ");
analogWrite(PWM_PIN, pwmGpio);
delay(5000);
#if FAN_WIRES == 4
Serial.print(" speed = "); Serial.println(getSpeed());
#else
Serial.println();
#endif
}
for (pwm = 90 ; pwm >= 0 ; pwm -= 10) {
Serial.print(pwm);
Serial.print("%: (");
pwmGpio = pwm * 2.5;
Serial.print(pwmGpio);
Serial.print(") ");
analogWrite(PWM_PIN, pwmGpio);
delay(5000);
#if FAN_WIRES == 4
Serial.print(" speed = "); Serial.println(getSpeed());
#else
Serial.println();
#endif
}
}
#if FAN_WIRES == 4
unsigned int getSpeed() {
static unsigned long lastMillis;
static unsigned int lastRead;
unsigned long elapsed = millis() - lastMillis;
if (elapsed > 1000) {
detachInterrupt(digitalPinToInterrupt(SENSOR_PIN));
double correctionFactor = 1000.0 / elapsed;
lastRead = correctionFactor * revs / 2 * 60;
revs = 0;
lastMillis = millis();
attachInterrupt(digitalPinToInterrupt(SENSOR_PIN), interruptHandler, FALLING);
return lastRead;
}
}
void interruptHandler(void) {
revs++;
}
#endif