add lifeline

lifeline/src/main.rs

@@ -0,0 +1,14 @@
+use std::time::Duration;
+
+mod sound;
+
+use sound::{notes::*, Song};
+
+const SUCCESS_SONG: Song = Song(&[(Some(A_4), Duration::from_millis(100))]);
+
+fn main() {
+    std::fs::write("/sys/class/pwm/pwmchip0/export", "0").unwrap();
+    let res = SUCCESS_SONG.play();
+    std::fs::write("/sys/class/pwm/pwmchip0/unexport", "0").unwrap();
+    res.unwrap();
+}