diff --git a/rotary_encoder.rb b/rotary_encoder.rb
new file mode 100644
index 0000000..60ef57b
--- /dev/null
+++ b/rotary_encoder.rb
@@ -0,0 +1,39 @@
+require 'rpi_gpio'
+
+RPi::GPIO.set_numbering :bcm
+
+CLOCK = 17
+DATA = 18
+
+RPi::GPIO.setup(CLOCK, as: :input)
+RPi::GPIO.setup(DATA, as: :input)
+
+def dtState
+  RPi::GPIO.high?(DATA) ? 1 : 0
+end
+
+def clock_state
+  RPi::GPIO.high?(CLOCK) ? 1 : 0
+end
+
+counter = 0
+clock_last_state = clock_state
+
+loop do
+  if clock_state != clock_last_state
+    if dtState != clock_state
+      counter += 1
+    else
+      counter -= 1
+    end
+
+    puts counter
+  end
+
+  clock_last_state = clock_state
+  sleep 0.01
+end
+
+at_exit do
+  RPi::GPIO.clean_up
+end