diff --git a/mozc-nazoru/bin/nazoru-input b/mozc-nazoru/bin/nazoru-input
index fb75e41..99839f5 100755
--- a/mozc-nazoru/bin/nazoru-input
+++ b/mozc-nazoru/bin/nazoru-input
@@ -16,8 +16,12 @@
 # limitations under the License.
 
 from __future__ import print_function
-from nazoru.led import LED_BLUE, LED_RED
+from nazoru.led import LED_BLUE, LED_RED, LED_CHASSIS
+import time
 LED_RED.blink(1)
+LED_CHASSIS.on()
+time.sleep(1)
+LED_CHASSIS.off()
 
 import argparse
 import os
@@ -48,6 +52,7 @@ def main():
 
   LED_RED.off()
   LED_BLUE.blink(1)
+  LED_CHASSIS.set_brightness(5)
 
   print('Ready. Please input your scrrible.')
   while True:
@@ -60,9 +65,11 @@ def main():
       print('done.')
       break
 
+    LED_CHASSIS.set_brightness(100)
     LED_RED.on()
     result = predictor.predict_top_n(data, 5)
     LED_RED.off()
+    LED_CHASSIS.set_brightness(5)
 
     print('\n=== RESULTS ===')
     for item in result:
diff --git a/mozc-nazoru/setup.py b/mozc-nazoru/setup.py
index aed5e6f..2093af7 100755
--- a/mozc-nazoru/setup.py
+++ b/mozc-nazoru/setup.py
@@ -67,6 +67,7 @@ setup(
         'tensorflow',
         'enum34;python_version<"3.4"',
         'pyserial',
-        'evdev;platform_system=="Linux"'
+        'evdev;platform_system=="Linux"',
+        'wiringpi'
     ]
   )
diff --git a/mozc-nazoru/src/nazoru/led.py b/mozc-nazoru/src/nazoru/led.py
index 3a3c2a0..fa44644 100644
--- a/mozc-nazoru/src/nazoru/led.py
+++ b/mozc-nazoru/src/nazoru/led.py
@@ -16,7 +16,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-class LEDBase():
+class LEDBase(object):
   def __init__(self, pin):
     self._pin = pin
   def on(self):
@@ -25,17 +25,19 @@ class LEDBase():
     pass
   def blink(self, interval):
     pass
+  def set_brightness(self, brightness):
+    pass
 
 try:
   import RPi.GPIO as GPIO
   import threading
+  GPIO.setmode(GPIO.BOARD)
 
   class LED(LEDBase):
     ON = 'ON'
     OFF = 'OFF'
 
     def __init__(self, pin):
-      GPIO.setmode(GPIO.BOARD)
       self._pin = pin
       self._lock = threading.Lock()
       self._timer = None
@@ -72,11 +74,72 @@ try:
         self._timer.cancel()
         self._timer = None
 
+  import wiringpi
+  wiringpi.wiringPiSetupPhys()
+  class SlowLED(LEDBase):
+    DUTY_MAX = 1024
+    INTERVAL_MS = 10
+
+    def __init__(self, pin, delay_ms):
+      self._pin = pin
+      self._delay_ms = delay_ms
+      wiringpi.pinMode(pin, wiringpi.GPIO.PWM_OUTPUT)
+      self._target_duty = 0
+      self._current_duty = 0
+      self._remaining_cycles = 0
+      self._lock = threading.Lock()
+      self._timer = None
+      self.off()
+
+    # Called every 10ms
+    def _update(self):
+      with self._lock:
+        diff = (self._target_duty - self._current_duty) // \
+               self._remaining_cycles
+        self._current_duty += diff
+        self._remaining_cycles -= 1
+        self._set_duty_immediate(self._current_duty)
+        if self._remaining_cycles == 0:
+          self._timer.cancel()
+          self._timer = None
+          return
+        self._timer = threading.Timer(self.INTERVAL_MS * 0.001, self._update)
+        self._timer.daemon = True
+        self._timer.start()
+
+
+    # |duty|: 0 - 100
+    def _set_duty_immediate(self, duty):
+      wiringpi.pwmWrite(self._pin, int(self.DUTY_MAX * duty // 100))
+
+    def _set_duty_slow(self, duty, time_ms):
+      with self._lock:
+        self._target_duty = duty
+        self._remaining_cycles = time_ms // self.INTERVAL_MS
+        if self._timer is None:
+          self._timer = threading.Timer(self.INTERVAL_MS * 0.001, self._update)
+          self._timer.daemon = True
+          self._timer.start()
+
+    def on(self):
+      self._set_duty_slow(100, self._delay_ms)
+
+    def off(self):
+      self._set_duty_slow(0, self._delay_ms)
+
+    # |brightness|: 0 - 100
+    def set_brightness(self, brightness):
+      self._set_duty_slow(brightness, self._delay_ms)
+
 except ImportError as e:
   import sys
 
   class LED(LEDBase):
     pass
+  class SlowLED(LEDBase):
+    def __init__(self, pin, delay_ms):
+      super(SlowLED, self).__init__(pin)
 
 LED_BLUE = LED(38)
 LED_RED = LED(40)
+LED_CHASSIS = SlowLED(32, 500)