diff --git a/README.md b/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..d447fdb6f83772b96e3f2ffa8d04ec00d9319630
--- /dev/null
+++ b/README.md
@@ -0,0 +1,38 @@
+# Android Sensor Sharing
+
+## Data format
+
+The data format used for publishing messages over MQTT is described.
+
+Each group of data (orientation, brightness, light state) can be send individually or together by
+ticking the corresponding checkbox or touching the toggle button inside the app.
+
+JSON format is used to package the data.
+
+Orientation and brightness are send continuously whereas the light state is only send by pressing the
+toggle button.
+
+### Brightness
+
+- MQTT topic: ``sensors/phone/brightness``
+- payload: ``{"brightness":67.0}``
+
+### Orientation
+
+- Orientation values are in the AHRS (yaw-pitch-roll angles)
+- [Madwick](http://x-io.co.uk/open-source-imu-and-ahrs-algorithms/) algorithm is used
+
+- MQTT topic: ``sensors/phone/rotationahrs``
+- payload: ``{"roll":-168.21172,"pitch":22.937801,"heading":28.27002}``
+
+### Light State
+
+- this is a one on/off thing. Message is only send when the toggle button is touched
+
+- MQTT topic: ``sensors/phone/onoff``
+- playload: ``{"on":true}``
+
+## Use Cases
+
+- IoSense (Smart Lighting Demo with the IoSense STK)
+- OpenLicht
\ No newline at end of file