diff --git a/matrix8x8.py b/matrix8x8.py
index b417f9c..62d2550 100644
--- a/matrix8x8.py
+++ b/matrix8x8.py
@@ -1,4 +1,4 @@
-import pyb
+from machine import I2C, Pin
 
 
 class Matrix8x8:
@@ -31,10 +31,11 @@ def __init__(self, i2c_bus=1, addr=0x70, brightness=15, i2c=None):
         if i2c:
             self.i2c = i2c
         else:
-            self.i2c = pyb.I2C(i2c_bus, pyb.I2C.MASTER, baudrate=400000)
+            self.i2c = I2C(scl=Pin(5), sda=Pin(4), freq=100000)
+            self.i2c.start()
 
         # set HT16K33 oscillator on
-        self._send(0x21)
+        self._send(b'\x21')
 
         self.set_brightness(brightness)
         self.clear()
@@ -44,25 +45,20 @@ def _send(self, data):
         """
         Send data over I2C.
         """
-        self.i2c.send(data, self.addr)
+        self.i2c.writeto(self.addr, data)
 
     def _send_row(self, row):
         """
         Send single row over I2C.
         """
-        data = bytes((self.row_addr[row], rotate_right(self.buf[row])))
+        data = bytes((self.row_addr[row], self.buf[row]))
         self._send(data)
 
     def _send_buf(self):
         """
         Send buffer over I2C.
         """
-        data = bytearray(16)
-        i = 1
-        for byte in self.buf:
-            data[i] = rotate_right(byte)
-            i += 2
-        self._send(data)
+        self._send(self.buf)
 
     def _clear_column(self, column):
         """
@@ -94,7 +90,7 @@ def on(self):
         Turn on display.
         """
         self.is_on = True
-        self._send(0x81 | self._blinking << 1)
+        self._send(bytes([0x81 | self._blinking << 1]))
 
     def off(self):
         """
@@ -102,13 +98,13 @@ def off(self):
         brightness, blinking, ...).
         """
         self.is_on = False
-        self._send(0x80)
+        self._send(b'\x80')
 
     def set_brightness(self, value):
         """
         Set display brightness. Value from 0 (min) to 15 (max).
         """
-        self._send(0xE0 | value)
+        self._send(bytes([0xE0 | value]))
 
     def set_blinking(self, mode):
         """
@@ -179,14 +175,3 @@ def clear_pixel(self, row, column):
         self.buf[row] &= ~(0x80 >> column)
         self._send_row(row)
 
-
-def rotate_right(byte):
-    """
-    Rotate bits right.
-    """
-    byte &= 0xFF
-    bit = byte & 0x01
-    byte >>= 1
-    if(bit):
-        byte |= 0x80
-    return byte