#define fan_1 11
#define fan_2 10

int veloc = 5;

void setup() {
    Serial.begin(115200);
    pinMode(fan_1,OUTPUT);
    pinMode(fan_2,OUTPUT); 
}

void loop() {
    analogWrite(fan_1, 100);
    delay(2000);
    analogWrite(fan_1, 100);
    delay(5000);
    analogWrite(fan_1, 255);
    delay(10000);
}