There are a number of Q Brain settings we need to configure before the quadcopter will fly properly. In this step, we will use a BESC programming card to program the Q Brain.
Before we connect the Q Brain to the flight controller, we will need to program the Q Brain. Programming the Q Brain, or any ESC, involves adjusting a number of settings related to the electrical system and flight performance. To program the Q Brain, we will use the BESC Programming Card and the connection hub that came with the Q Brain.
First, if you take a look at the Q Brain connection hub, you will notice that there are four rows of three pins each. Now if you look at the Q Brain, you will notice four sets of colored wires terminated with three-pin headers. We will discuss exactly what each of these wires is for in the next step, but for now, just note that among these colored wire connectors, only one actually has three wires connected to it, a black one, a red one, and a white one. Plug this connector into the top row of the connection hub with the black wire to the left and white wire to the right. Now plug in all of the remaining colored wires with the wires themselves on the right side of the connection hub.
With all the Q Brain control leads connected to the hub, plug the connection hub wire into the top of the BESC Programming Card in the position marked BEC. Notice that there are three pins on this connector, labeled signal, +, and -. The white wire from the connection hub should be connected to the signal pin. Finally, plug the battery into the Q Brain battery connecter we soldered on earlier.
The BESC Programming Card should now light up with LEDs that indicate the current settings on the Q Brain. Each row of lights represents a setting on the Q Brain:
Battery Type: Li-xx or Ni-xx
- Brake: on/off
The brake setting determines how the motors behave when the throttle is set to zero.
- On: The motors stop immediately when the throttle is set to zero. This setting allows the quadcopter to lose altitude more quickly, and can also be very useful in preventing damage in an impending crash, but additional power is required to stop the motors, which reduces battery life.
- Off: When the throttle is set to zero, the motos coast to a stop naturally. This action requires no additional power and so it increases battery life, but in an emergency situation the props may still be spinning after the throttle is zeroed out.
The battery type setting simply specifies the type of battery used to power the quadcopter. Cut Off Type: low/middle/high
The cut off type setting specifies at which point, as the battery drains and starts outputting less voltage, the quadcopter will cut power to prevent damage from a low-voltage condition. Start Mode: normal/soft/very soft
The start mode setting determines how quickly the motors accelerate from stationary during takeoff. A setting of normal means the quadcopter will get off the ground very quickly. A setting of soft or very soft means the quadcopter will get off the ground more slowly, which can make for more appealing videos. Timing Mode: low/middle/fast
The timing mode setting is complex, but it roughly adjusts the speed with which the ESC communicates with the motors. In general, motors with a higher number of poles should use higher timing modes, and motors with fewer poles should use lower timing modes. Music
The music setting can be used to play music through your ESCs my adjusting the vibrational frequency of the motors. I have no idea why this particular feature exists, but it is actually really fun and very amusing. You can use the music setting to set a song that the quadcopter will play every time you start it up. To set a song, select the music setting and use the left/right keys. There are many different songs that are represented by different combinations of LEDs. Governor Mode: on/off
Governor mode basically determines how the Q Brain will adjust the lift produced by each motor. With governor mode on, the speed of the rotors remains constant and lift is adjusted by adjusting the amount of power delivered to the motor. With governor mode off, the lift produced by each motor is adjusted by adjusting the rotational speed of the motor.
For our SK450 Dead Cat quadcopter, I recommend using the following settings when you are first starting to fly, particularly if you plan to do aerial photography:
- Brake → Off
- Battery Type → Li-xx
- Cut Off Type → Low
- Start Mode → Soft
- Timing Mode → Middle
- Music → (feel free to experiment)
- Governor Mode → Off