The flight controller system interprets the signals from the radio control system and sends the appropraite response to the electronic speed controllers which in turn control the power sent to the motors. In addition to this the flight controller has stabilization sensors to "know" the position of the quadcopter racer such as if it is level or not. In the photo below we can see the radio receiver connected to the Open Pilot CC3D flight controller as well as the signal wires from each of the four ESCs (electronic speed controllers).
Now that we can see how the racing quadcopter system all goes together (less the FPV system), let's have a look at how to connect the CC3D flight controller. Covering this now will make it that much easier when we mount all the components in our carbon fiber frame. First, let's look at the CC3D flight controller itself.
The first thing that we need to be aware of is that the orientation of the CC3D flight controller is very important and the directional arrow on the board or board casing must point to the front of our quadcopter racer. For clarity we have marked the direction on the case with a black Sharpie marker. If you can't see the directional arrow on your board just remember that the USB port ALWAYS faces towards the REAR of the quadcopter (above photo).
To the right of the directional arrow is three rows of six OUTPUT pins. The first row is the signal, the second row is positive and the third row is negative. We will connect the orange|red|brown wires from each of our ESCs to these output pins with the ORANGE wires always on the SIGNAL pins and connected in the following order; M1 ESC to the first row, M2 ESC to the second row, M3 ESC to the third row and M4 ESC to the fourth row (below three photos).
Next we need to connect the radio receiver to our board. To the left of the directional arrow is the INPUT port where we will connect the radio receiver. Plug one end of the SIX wire harness that came with the board into this port the other end we will connect to the FlySky FS-R6B receiver (below two photos).
When connecting the wires to the FlySky FS-R6B radio receiver connect the white|red|black three wire to channel one with the white wire on the signal pin. Although the Radio Wizard in the Open Pilot Ground Station software will sort out the rest of the connections, the following is what we used which gave us no problems at all:
- Channel 1: white|red|black with white on the signal pin
- Channel 2: blue wire with the wire on the signal pin
- Channel 3: chartreuse wire with the wire on the signal pin
- Channel 4: green wire with the wire on the signal pin
- Channel 5: yellow wire with the wire on the signal pin
- Channel 6: black wire with the wire on the signal pin
- BAT: the row of pins identified as BAT should have no wires connected to it