User Input and Communication Interface

User Command Interface

The input layer is uniformly encapsulated in UserCommandInterface, responsible for converting user operations into commands recognizable by the state machine.

Interface Example

virtual void Start() = 0;
virtual void Stop() = 0;
virtual UserCommand* GetUserCommand() = 0;

State Feedback Binding Example

uc_ptr_->SetMotionStateFeedback(&StateBase::msfb_);

Keyboard Input

The keyboard input mode corresponds to KeyboardInterface, based on libevdev for direct reading of /dev/input devices.

Mode Selection Example

std::make_shared<q::QStateMachine>(RobotName::Lite3, RemoteCommandType::kKeyBoard);

Key Mapping

Key	Function	Valid State
z	Standing up	Only in WaitingForStand state
c	RL control	Only in StandingUp state
r	Joint damping	Any state
wasd	Movement (ramp-up velocity increment)	RL control state
qe	Rotation	RL control state
ESC	Exit	Any state

Gamepad Communication Interface

The Retroid gamepad input is based on RetroidGamepadInterface, receiving gamepad data by subscribing to the /GAMEPAD_DATA topic. Gamepad data is published by RetroidGamepadPublisher in lite3_transfer.

Gamepad Startup Example

uc_ptr_ = std::make_shared<RetroidGamepadInterface>(robot_name_, ri_ptr_->get_node());

Gamepad Subscription Example

gamepad_sub_ = node_->create_subscription<drdds::msg::GamepadData>(
    "/GAMEPAD_DATA", 10,
    std::bind(&RetroidGamepadInterface::GamepadDataCallback, this, std::placeholders::_1));

Gamepad Mapping Example

Button handling in RetroidGamepadInterface (based on bitmask):

• Y button (rising edge) → Standing Up
• A button (rising edge) → RL Control
• Left joystick button + Right joystick button pressed simultaneously → Joint Damping (emergency damping)