diff --git a/src/sensor.py b/src/sensor.py
index e69de29..fff9d63 100644
--- a/src/sensor.py
+++ b/src/sensor.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+
+import ev3dev.ev3 as ev3
+
+
+# add enum for color definitions
+
+class Sensor:
+    def __init__(self):
+        self._sensor = ev3.ColorSensor()
+        self._sensor.mode = 'REF-RAW'
+
+    def iscolor(self, color):
+        curcol = self._sensor.bin_data("hhh")
+        if curcol == curcol:
+            return True
+        else:
+            return False
+
+    # see https://stackoverflow.com/questions/687261/converting-rgb-to-grayscale-intensity
+    def getbrightness(self):
+        if(self._sensor.mode == 'REF-RAW'):
+            return self._sensor.value
+        else:
+            print("ERROR: incorrect sensor mode.")
+
+    def setmode(self, newmode):
+        self._sensor.mode = newmode
diff --git a/src/wheel.py b/src/wheel.py
index 0340914..90ab41a 100644
--- a/src/wheel.py
+++ b/src/wheel.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 import ev3dev.ev3 as ev3
 
 
@@ -5,8 +7,7 @@ class Wheel:
     def __init__(self, port):
         self._motor = ev3.LargeMotor(port)
         self._motor.stop_action = 'brake'
-        self._speed = 20
-        self._motor.duty_cycle_sp = self._speed
+        self._motor.duty_cycle_sp = 20
 
     def run(self):
         self._motor.run_direct()
@@ -15,14 +16,12 @@ class Wheel:
         self._motor.stop()
 
     def speed_set(self, newspeed):
-        self._speed = newspeed
-        self._motor.duty_cycle_sp = self._speed
+        self._motor.duty_cycle_sp = newspeed
 
     def speed_mod(self, modifier):
-        self._speed = self._speed + modifier
-        self._motor.duty_cycle_sp = self._speed
+        self._motor.duty_cycle_sp = self._motor.duty_cycle_sp + modifier
 
     def getmovement(self):
         self.position = self._motor.position
-        self._motor.position.reset()
+        self._motor.position = 0
         return self.position