diff --git a/SUMMARY.md b/SUMMARY.md
index 245c4d7..bd79073 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -1,4 +1,5 @@
 # Table of contents
 
 * [CraftBeerPi](README.md)
+* [Development](development.md)
 
diff --git a/development.md b/development.md
new file mode 100644
index 0000000..4eb4ebb
--- /dev/null
+++ b/development.md
@@ -0,0 +1,62 @@
+# Development
+
+## Custom Sensor
+
+```python
+# -*- coding: utf-8 -*-
+import asyncio
+import random
+import re
+import random
+from aiohttp import web
+from cbpi.api import *
+
+
+
+@parameters([Property.Number(label="Param1", configurable=True), 
+             Property.Text(label="Param2", configurable=True, default_value="HALLO"), 
+             Property.Select(label="Param3", options=[1,2,4]), 
+             Property.Sensor(label="Param4"), 
+             Property.Actor(label="Param5")])
+class CustomSensor(CBPiSensor):
+    
+    def __init__(self, cbpi, id, props):
+    
+        super(CustomSensor, self).__init__(cbpi, id, props)
+        self.value = 0
+
+    
+    @action(key="Test", parameters=[])
+    async def action1(self, **kwargs):
+        '''
+        A custom action. Which can be called from the user interface
+        '''
+        print("ACTION!", kwargs)
+
+    async def run(self):
+        '''
+        This method is executed asynchronousely 
+        In this example the code is executed every second
+        '''
+        while self.running is True:
+            self.value = random.randint(0,50)
+            self.push_update(self.value)
+            await asyncio.sleep(1)
+    
+    def get_state(self):
+        # return the current state of the sensor
+        return dict(value=self.value)
+
+
+def setup(cbpi):
+
+    '''
+    This method is called by the server during startup 
+    Here you need to register your plugins at the server
+    
+    :param cbpi: the cbpi core 
+    :return: 
+    '''
+    cbpi.plugin.register("CustomSensor", CustomSensor)
+```
+