Servo - November 2012

and working with the input and output connectors on the ArduPilot. This translates to ample opportunity to slice a finger or two. Keep the props off until the very end, and don't forget to balance the props — there are lots of examples on YouTube if you're new at this.

Firmware setup of the ArduPilot is a breeze, thanks to the menu-driven Mission Planner. Figure 12 shows the first step in the menu-driven setup, calibrating the R/C unit mapping onto the ArduPilot. I could have dropped into Arduino source code and set these parameters manually, but there was no need. As you can see in Figure 12, the next steps are listed in order, starting with flight modes and ending with the Planner. Setup is painless and straightforward, requiring all of five minutes to complete.

Time to Get Physical

FIGURE 11. ArduPilot setup with external power and USB connectivity to the Mission Planner software.

After setup and testing, including checking and — if necessary — correcting prop rotation direction, it's time to drop in a battery, boot the laptop, and take it for a spin. Figure 13 shows the quadcopter ready to go. Note that there's no on-off switch on this creature. Once you plug in the battery, the ESCs issue various beeps and buzzes, so you'd better stand back. There is an arming sequence which requires you to hold the throttle stick in a certain position for four seconds. A constant red light signifies the ArduPilot is armed and ready to go.

Figure 14 shows one of many views available within the Mission Planner. This view shows the artificial horizon in the upper left, geo-location on the right, and basic sensor information from the ArduPilot on the lower left. In this example, ground speed is 0 (the quadcopter was on my workbench), while altitude is shown as 2. 14 feet.

In addition to a realistic cockpit experience, you can look at the raw sensor data in real time, as shown in

FIGURE 12. R/C controller mapping within the Mission Planner system.

FIGURE 13. ArduPilot mounted within the quadcopter frame, ready to go.

Figure 15. In addition to instantaneous graphical displays of roll, pitch, and yaw dials, you can see the plots of data from the accelerometer and gyro over time.