diff --git a/code/encoder.py b/code/encoder.py
new file mode 100644
index 0000000..d42ca3c
--- /dev/null
+++ b/code/encoder.py
@@ -0,0 +1,121 @@
+# -*- coding: utf-8 -*-
+"""MicroPython rotary encoder library.
+Usage:
+    from time import sleep_ms
+    from encoder import Encoder
+    # Connect CLK to D6, DT to D5, GND to GND and + to 3V3
+    enc = Encoder(pin_clk=12, pin_dt=14)
+    def readloop(e):
+        oldval = 0
+        while True:
+            val = enc.value
+            if oldval != val:
+                print(val)
+                oldval = val
+            sleep_ms(50)
+    readloop(e)
+
+Source :
+https://github.com/SpotlightKid/micropython-stm-lib/blob/master/encoder/encoder.py
+"""
+
+from machine import Pin
+
+ENC_STATES = (
+    0,   # 00 00
+    -1,  # 00 01
+    1,   # 00 10
+    0,   # 00 11
+    1,   # 01 00
+    0,   # 01 01
+    0,   # 01 10
+    -1,  # 01 11
+    -1,  # 10 00
+    0,   # 10 01
+    0,   # 10 10
+    1,   # 10 11
+    0,   # 11 00
+    1,   # 11 01
+    -1,  # 11 10
+    0    # 11 11
+)
+ACCEL_THRESHOLD = const(5)
+
+
+class Encoder(object):
+    def __init__(self, pin_clk, pin_dt, pin_mode=None, clicks=1,
+                 min_val=0, max_val=100, accel=0, reverse=False):
+        self.pin_clk = (pin_clk if isinstance(pin_clk, Pin) else
+                        Pin(pin_clk, Pin.IN, pin_mode))
+        self.pin_dt = (pin_dt if isinstance(pin_dt, Pin) else
+                       Pin(pin_dt, Pin.IN, pin_mode))
+
+        self.min_val = min_val * clicks
+        self.max_val = max_val * clicks
+        self.accel = int((max_val - min_val) / 100 * accel)
+        self.max_accel = int((max_val - min_val) / 2)
+        self.clicks = clicks
+        self.reverse = 1 if reverse else -1
+
+        # The following variables are assigned to in the interrupt callback,
+        # so we have to allocate them here.
+        self._value = 0
+        self._readings = 0
+        self._state = 0
+        self.cur_accel = 0
+
+        self.set_callbacks(self._callback)
+
+    def _callback(self, line):
+        self._readings = (self._readings << 2 | self.pin_clk.value() << 1 |
+                          self.pin_dt.value()) & 0x0f
+
+        self._state = ENC_STATES[self._readings] * self.reverse
+
+        if self._state:
+            self.cur_accel = min(self.max_accel, self.cur_accel + self.accel)
+
+            self._value = min(self.max_val, max(self.min_val, self._value +
+                                                (1 + (self.cur_accel >> ACCEL_THRESHOLD)) *
+                                                self._state))
+
+    def set_callbacks(self, callback=None):
+        mode = Pin.IRQ_RISING | Pin.IRQ_FALLING
+        self.irq_clk = self.pin_clk.irq(trigger=mode, handler=callback)
+        self.irq_dt = self.pin_dt.irq(trigger=mode, handler=callback)
+
+    def close(self):
+        self.set_callbacks(None)
+        self.irq_clk = self.irq_dt = None
+
+    @property
+    def value(self):
+        return self._value // self.clicks
+
+    def reset(self):
+        self._value = 0
+
+
+def test(enc=None, **kwargs):
+    from time import sleep_ms
+    rate = kwargs.pop('rate', 20)
+
+    if not isinstance(enc, Encoder):
+        cls = kwargs.pop('encoder_cls', Encoder)
+        kwargs.setdefault('pin_clk', 12)
+        kwargs.setdefault('pin_dt', 14)
+        kwargs.setdefault('clicks', 4)
+        enc = cls(**kwargs)
+
+    oldval = 0
+    try:
+        while True:
+            val = enc.value
+            if oldval != val:
+                print(val)
+                oldval = val
+
+            enc.cur_accel = max(0, enc.cur_accel - enc.accel)
+            sleep_ms(1000 // rate)
+    except:
+        enc.close()