01 EM7180 SENtral Sensor Hub
The EM7180 SENtral Sensor Hub onboard your LadybugFC has already been flashed with its own firmware for fusing the the accelerometer, gyrometer, and magnetometer into a set of quaternion readings from which the vehicle's orientation (roll, pitch, yaw) will be computed. To get the EM7180 to talk to your LadybugFC (or other Arduino-compatible board), we've provided a library that you should clone into your Arduino libraries folder. As usual with Arduino, you'll need to close and re-open the Arduino IDE to access the new libraries. Under File/Examples, you should see a new menu EM1780.
In the Arduino IDE, use Tools/Board to select Ladybug Flight Controller, and Tools/Port to choose the serial port on which you've connected the LadybugFC. Then flash the sketch in File/Examples/EM7180/GetInfo onto your LadybugFC. In the Serial Monitor (Tools/Serial Monitor) you should see a report showing you status of the EM7180. The report will repeat every second, so you can view it at any time after flashing the GetInfo sketch.
Now would be a good time to calibrate the EM7180 onboard your LadybugFC, as described in this tutorial. Although the LadybugFC will fly your vehicle pretty well without calibration, you'll want to calibrate it to get the full advantage of accuracy provided by the EM7180. Using the Arduino IDE, flash the sketch in File/Examples/EM7180/WarmStartAccCal onto your LadybugFC. Follow the directions in the tutorial to complete the calibration.
Next: Choosing a Receiver