use hc_sr04::{HcSr04, Unit};

let mut ultrasonic_front = HcSr04::new(
    7,          // TRIGGER
    1,          // ECHO
    Some(23_f32) 
).unwrap();

let mut ultrasonic_left = HcSr04::new(
    0,
    4,
    Some(23_f32) 
).unwrap();

let mut ultrasonic_right = HcSr04::new(
    2,
    5,
    Some(23_f32) 
).unwrap();

let mut ultrasonic_rear = HcSr04::new(
    3,
    6,
    Some(23_f32) 
).unwrap();

match ultrasonic_front.measure_distance(Unit::Meters).unwrap() {
    Some(dist) => println!("[FRONT] Distance: {.2}m", dist),
    None => println!("Object out of range"),
}

match ultrasonic_left.measure_distance(Unit::Meters).unwrap() {
    Some(dist) => println!("[LEFT] Distance: {.2}m", dist),
    None => println!("Object out of range"),
}

match ultrasonic_right.measure_distance(Unit::Meters).unwrap() {
    Some(dist) => println!("[RIGHT] Distance: {.2}m", dist),
    None => println!("Object out of range"),
}

match ultrasonic_rear.measure_distance(Unit::Meters).unwrap() {
    Some(dist) => println!("[BACK] Distance: {.2}m", dist),
    None => println!("Object out of range"),
}