This section gives an overview of the pinout for various ports on the RDDRONE-FMUK66.
Most interfaces on the RDDRONE-FMUK66 use the JST-GH connectors as specified in the Dronecode Autopilot Connector Standard. The PWM interface uses "standard" RC hobby servo connections. These PWM connectors are 3 pins spaced 0.100" apart.
The male JST-GH connector has a clip on top. As described in the Dronecode standard, the first (leftmost) wire is usually the positive voltage. In some cables this wire is red. The last (rightmost) wire is ground. The wires in between carry different kinds of signals, depending on the function.
The following pictures give an overview of all connectors (and LED indicators) on the RDDRONE-FMUK66. Most of the labels in the pictures are the same as the labels on the PCB itself. Below you can find further details about the functions of the different ports.
The serial port can be used to communicate with the FMU either remotely or with a companion computer. Often telemetry radios are connected to this port to provide a wireless connection with a ground control station. By default, PX4 listens and communicates using the MAVLink protocol on this port.
The arming switch is a safety feature which prevents take-off when the switch is not active. Further information about the arming switch itself is available at a seperate page.
The RDDRONE-FMUK66 features two CAN (Controller Area Network) busses. PX4 implements the UAVCAN protocol, and supports some motor controllers, sensors and GPS solutions with a CAN interface. The current HoverGames kit does not include any hardware with a CAN interface, except the FMU itself.
The FMU has a TJA110x two wire automotive ethernet (100BASE-T1) transceiver . However, this is not yet supported by PX4. Adding driver support to PX4 and implementing the protocol might become a HoverGames task/challenge in the future.