Merge pull request tock#483 from tock/fix-buttons

examples: buttons: fix

examples/buttons.rs

@@ -3,24 +3,38 @@
 #![no_main]
 #![no_std]
 
+use core::fmt::Write;
 use libtock::buttons::{ButtonListener, Buttons};
+use libtock::console::Console;
+use libtock::leds::Leds;
 use libtock::runtime::{set_main, stack_size};
 use libtock_platform::{share, Syscalls};
 use libtock_runtime::TockSyscalls;
 
 set_main! {main}
-stack_size! {0x100}
+stack_size! {0x1000}
 
 fn main() {
-    let listener = ButtonListener(|_button, _state| {
-        // TODO when a console driver will be available
-        // println!("button {}: {}", button, state);
+    let listener = ButtonListener(|button, state| {
+        let _ = Leds::toggle(button);
+        writeln!(Console::writer(), "button {:?}: {:?}", button, state).unwrap();
     });
-    if let Ok(_buttons_count) = Buttons::count() {
-        if let Ok(()) = share::scope(|subscribe| Buttons::register_listener(&listener, subscribe)) {
+    if let Ok(buttons_count) = Buttons::count() {
+        writeln!(Console::writer(), "button count: {}", buttons_count).unwrap();
+
+        share::scope(|subscribe| {
+            // Subscribe to the button callback.
+            Buttons::register_listener(&listener, subscribe).unwrap();
+
+            // Enable interrupts for each button press.
+            for i in 0..buttons_count {
+                Buttons::enable_interrupts(i).unwrap();
+            }
+
+            // Wait for buttons to be pressed.
             loop {
                 TockSyscalls::yield_wait();
             }
-        }
+        });
     }
 }