diff --git a/src/main.rs b/src/main.rs
index 18e5a79..f17f7fb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -121,15 +121,16 @@ fn main() -> ! {
         display.clear(TriColor::White);
 
         ctx.button_pressed = kbd.pressed();
-        app.update(&ctx, &mut trng);
-        app.draw(&mut display);
+        if !ctx.button_pressed.is_none() {
+            app.update(&ctx, &mut trng);
+            app.draw(&mut display);
+            // TODO: try fast update?
+            driver.full_update(&display).unwrap();
+        }
 
-        // TODO: try fast update?
-        driver.full_update(&display).unwrap();
-
-        log::info!("Sleeping for 5s...");
+        log::info!("Sleeping for 100ms...");
         driver.sleep().unwrap();
-        delay.delay(5_000.millis());
+        delay.delay(100.millis());
     }
 }