added depedency for gpio, implemented proof of concept alarm

src/main.rs

@@ -1,6 +1,34 @@
 // This project is licensed under MIT Licese.
 // See the LICENSE folder for details.
 
-fn main() {
-    println!("Hello, world!!");
+use std::thread;
+
+use gpio_cdev::{Chip, LineRequestFlags};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut chip = Chip::new("/dev/gpiochip0")?;
+    alarm(&mut chip)?;
+    Ok(())
+}
+
+fn alarm(chip: &mut Chip) -> Result<(), Box<dyn std::error::Error>> {
+    let beeper = chip
+        .get_line(17)?
+        .request(LineRequestFlags::OUTPUT, 0, "my-gpio")?;
+
+    for _ in 0..5 {
+        beeper.set_value(1)?;
+        thread::sleep(std::time::Duration::from_secs(1));
+        beeper.set_value(0)?;
+        thread::sleep(std::time::Duration::from_secs(1));
+    }
+
+    Ok(())
+}
+
+fn turn_off_led(chip: &mut Chip) -> Result<(), Box<dyn std::error::Error>> {
+    chip.get_line(17)?
+        .request(LineRequestFlags::OUTPUT, 0, "my-gpio")?
+        .set_value(0)?;
+    Ok(())
 }