hcsr04_example.sim

def measure : int : {
    bool timeout := false;
    int echo := 0;

    start_counter();
    
    while : read_counter() <= 2000 {
        digital_write(7, true);
    }
    digital_write(7, false);
    stop_counter();

    start_counter();
    while : not (digital_read(1)) and true {
        if : read_counter() > 200000000 {
            timeout := true;
            break;
        }
    }   
    stop_counter();
    
    if : not(timeout) and true {
        start_counter();
        while : digital_read(1) and true {
            if : read_counter() > 200000000 {
                timeout := true;
                break;
            }
            echo := read_counter();
        }
        stop_counter();
    }
    
    if : timeout and true {
        echo := 0;
    } 

    return echo;
}

while : true {
    int ping:= measure()*1000;

    if : ping > 292200 {
        digital_write(4, false);
    }
    else
    {
        digital_write(4, true);
    }
    delay(1000);
}