Rename the set_directions method on LedRing

This hopefully prevens confusion between "compass directions" and
LED ring cycle direction.

src/led_ring.rs

@@ -135,11 +135,11 @@ impl LedRing {
         }
     }
 
-    /// Turns on specific LEDs based on the direction array.
+    /// Turns on specific LEDs based on the "direction" array.
     ///
     /// When looking with the mini-USB port of the board held down (south), the directions of
     /// the array can be interpreted as: `[east, south, west, north]`.
-    pub fn set_directions(&mut self, directions: [bool; 4]) {
+    pub fn specific_on(&mut self, directions: [bool; 4]) {
         for (led, on_off) in self.leds.iter_mut().zip(directions.iter()) {
             if *on_off {
                 led.set_high();

src/main.rs

@@ -151,7 +151,7 @@ const APP: () = {
         resources.led_ring.lock(|led_ring| {
             if led_ring.is_mode_accel() {
                 let directions = [acc_y < 0, acc_x < 0, acc_y > 0, acc_x > 0];
-                led_ring.set_directions(directions);
+                led_ring.specific_on(directions);
                 schedule
                     .accel_leds(scheduled + LedRing::PERIOD.cycles())
                     .unwrap();