diff --git a/V1/led5/src/main.rs b/V1/led5/src/main.rs
index f5e750b..9cbf698 100644
--- a/V1/led5/src/main.rs
+++ b/V1/led5/src/main.rs
@@ -10,24 +10,6 @@ use std::time::Duration;
 
 use chan_signal::Signal;
 
-// static GPIO_BASE_PATH: &'static str = "/sys/class/gpio";
-// static GPIO_PATH: &'static str = "gpio{}/";
-// static GPIO_EXPORT: &'static str = "export";
-// static GPIO_UNEXPORT: &'static str = "unexport";
-// static GPIO_VALUE: &'static str = "value";
-// static GPIO_DIRECTION: &'static str = "direction";
-
-// static GPIO_BASE_PATH: &'static Path = Path::new("/sys/class/gpio");
-// static GPIO_EXPORT_PATH: &'static Path = GPIO_BASE_PATH.join("export").as_path();
-// static GPIO_UNEXPORT_PATH: &'static Path = GPIO_BASE_PATH.join("unexport").as_path();
-// static GPIO_PATH: &'static Path = GPIO_BASE_PATH.join("gpio{}").as_path();
-// static GPIO_VALUE_PATH: &'static Path = GPIO_PATH.join("value").as_path();
-// static GPIO_DIRECTION_PATH: &'static Path = GPIO_PATH.join("direction").as_path();
-
-// str0 = "asd"
-// str1 = concat!("Test", "Test");
-// str2 concat!(str1, "test");
-
 static GPIO_PORT_BTN: &'static str = "17";
 static GPIO_PORT_LED: &'static str = "18";
 
@@ -46,9 +28,13 @@ fn write(path: &str, value: &str) {
 
     file.write_all(value.as_bytes())
         .expect(format!("Write value '{}' to '{}' file failed", value, path).as_str());
+
+    #[cfg(debug_assertions)]
+    println!("Wrote value '{}' to '{}'.", value, path);
 }
 
 fn read(path: &str) -> String {
+    return String::new();
     let mut file = File::open(Path::new(path))
         .expect(format!("Open file '{}' failed", path).as_str());
     let mut contents = String::new();
@@ -56,6 +42,9 @@ fn read(path: &str) -> String {
     file.read_to_string(&mut contents)
         .expect(format!("Read from '{}' file failed", path).as_str());
 
+    #[cfg(debug_assertions)]
+    println!("Read value '{}' from '{}'.", contents, path);
+
     contents
 }
 
@@ -81,45 +70,57 @@ fn get_value(port: &str) -> String {
 fn main() {
     let signal = chan_signal::notify(&[Signal::INT, Signal::TERM]);
     let (sdone, rdone) = chan::sync(0);
-    thread::spawn(move || run(sdone));
+    let worker = thread::spawn(move || run(rdone));
 
-    // Wait for a signal or for work to be done.
     chan_select! {
-        signal.recv() -> signal => {
-            println!("received signal: {:?}", signal);
-            unexport(GPIO_PORT_BTN);
-            unexport(GPIO_PORT_LED);
+        default => {
+            worker.join();
         },
-        rdone.recv() => {
-            println!("Program completed normally.");
+        signal.recv() -> signal => {
+            #[cfg(debug_assertions)]
+            println!("received signal: {:?}", signal);
+
+            sdone.send(());
         }
     }
 }
-fn run(_sdone: chan::Sender<()>) {
+fn run(rdone: chan::Receiver<()>) {
     // init
     export(GPIO_PORT_BTN);
     export(GPIO_PORT_LED);
     set_direction(GPIO_PORT_BTN, GPIO_DIRECTION_IN);
     set_direction(GPIO_PORT_LED, GPIO_DIRECTION_OUT);
 
+    let tick = chan::tick(Duration::from_millis(1000 / 5));
     let mut on = false;
 
     loop {
-        let btn = get_value(GPIO_PORT_BTN);
+        chan_select! {
+            tick.recv() => {
+                #[cfg(debug_assertions)]
+                println!("tick");
 
-        if btn == GPIO_BTN_ON {
-            on = !on;
-        } else {
-            on = false;
-        }
+                let btn = get_value(GPIO_PORT_BTN);
 
-        if on {
-            set_value(GPIO_PORT_LED, GPIO_LED_ON);
-        }
-        else {
-            set_value(GPIO_PORT_LED, GPIO_LED_OFF);
-        }
+                if btn == GPIO_BTN_ON {
+                    on = !on;
+                } else {
+                    on = false;
+                }
 
-        thread::sleep(Duration::from_secs(1 / 5));
+                if on {
+                    set_value(GPIO_PORT_LED, GPIO_LED_ON);
+                }
+                else {
+                    set_value(GPIO_PORT_LED, GPIO_LED_OFF);
+                }
+            },
+            rdone.recv() => {
+                // unexport
+                unexport(GPIO_PORT_BTN);
+                unexport(GPIO_PORT_LED);
+                return;
+            },
+        }
     }
 }