If you already own a Taranis X9D (Plus) RC transmitter and want to use it as a controller, it can be configured to work with the Crazyflie Android client. Fortunately the transmitter is able to act as an USB Joystick (see https://github.com/opentx/opentx/wiki/OpenTX-USB-Joystick).

You should create a new model when using the Taranis as an USB Joystick:

• you can turn off both internal and external TX modules
• you need to configure the thrust input (Weight 50% and Offset 50%)
  • otherwise you can not use the full travel of the axis assigned to thrust
• Servos menu
  • invert Thrust (CH1)
  • invert Eleron (CH3)

You can also download the configuration as an EEPE file and install it with the OpenTX Companion application.

• USB Joystick EEPE file: usbjoystickforandroidcfclient.eepe.zip
• Download the Companion application here: http://www.open-tx.org/2015/05/04/opentx-2.0.17

Here are the necessary steps to configure the Crazyflie Android client:

1. Turn on the Taranis
2. Connect the Taranis with a USB cable and a USB host (OTG) adapter to the Android device
   • The Taranis screen should display a USB symbol when it's connected
3. Check that all sticks are in center position
4. Open the Crazyflie Android client
5. Go to Preferences → Controller Settings and switch Controller to Gamepad
6. Go to Gamepad axis and button mapping and configure the following axes
   • Right analog X axis should be AXIS_Y
   • Right analog Y axis should be AXIS_Z
   • Left analog X axis should be AXIS_RX
   • Left analog Y axis should be AXIS_X
7. Depending on the mode you are using on the Taranis (Mode 1 or 2), set the Mode in the Android app
   • Preferences → Flight control settings → Mode

1. Before connecting to the Crazyflie, check that all axes are working (values should change)
2. Attention: Always make sure that the thrust stick is all the way down before connecting to the Crazyflie
3. Connect to the Crazyflie 2 over BLE
   • If you have a Crazyflie 1 you need to use a (powered) USB hub to connect both the Taranis RC transmitter and the Crazyradio USB dongle