Solution 2

  1. #![deny(unsafe_code)]
  2. #![no_main]
  3. #![no_std]
  5. // You'll find this useful ;-)
  6. use core::f32::consts::PI;
  8. #[allow(unused_imports)]
  9. use aux15::{entry, iprint, iprintln, prelude::*, Direction, I16x3};
  10. use m::Float;
  12. #[entry]
  13. fn main() -> ! {
  14.     let (mut leds, mut lsm303dlhc, mut delay, _itm) = aux15::init();
  16.     loop {
  17.         let I16x3 { x, y, .. } = lsm303dlhc.mag().unwrap();
  19.         let theta = (y as f32).atan2(x as f32); // in radians
  21.         let dir = if theta < -7. * PI / 8. {
  22.             Direction::North
  23.         } else if theta < -5. * PI / 8. {
  24.             Direction::Northwest
  25.         } else if theta < -3. * PI / 8. {
  26.             Direction::West
  27.         } else if theta < -PI / 8. {
  28.             Direction::Southwest
  29.         } else if theta < PI / 8. {
  30.             Direction::South
  31.         } else if theta < 3. * PI / 8. {
  32.             Direction::Southeast
  33.         } else if theta < 5. * PI / 8. {
  34.             Direction::East
  35.         } else if theta < 7. * PI / 8. {
  36.             Direction::Northeast
  37.         } else {
  38.             Direction::North
  39.         };
  41.         leds.iter_mut().for_each(|led| led.off());
  42.         leds[dir].on();
  44.         delay.delay_ms(100_u8);
  45.     }
  46. }