Fix switch timer decrement

src/main.rs

@@ -80,7 +80,13 @@ fn main() -> ! {
         // This debouncing sucks ass and isn't good - doesn't matter, just for testing
         switch_count = match switch.is_low() {
             true => 1.0,
-            false => switch_count - 0.2,
+            false => {
+                if switch_count > 0.0 {
+                    switch_count - 0.2
+                } else {
+                    0.0
+                }
+            },
         };
 
         let val;