This ROS2 package processes all inputs from the gamepad_input_drive topic, and converts it into wheel speeds and angles which is used by the corresponding CAN firmware API calls. It also handles controlling the pantilt camera as well.

The main ROS nodes are:

• drive_control_node
• drive_firmware_node
• pantilit_control_node

These can be ran directly using Python (in separate terminals) or using a launch file.

To confirm that this is working, you can check for input by echoing the gamepad_input_drive or drive_speed_input topics. They should all respond dynamically to your controller input.

The control schema relies on a geared speed system where the rover will decelerate to 0 when receiving no input. It has two steering modes: tank and dynamic. Here is the full schema mapped:

Triangle -> switch between standard and tank control schemas

X -> accelerate forward

O -> accelerate backward

Square -> acknowledge faults (if the rover ever stops responding, hit this!)

Left Trigger (L2) -> gear down (decrease max speed)

Right Trigger (R2) -> gear up (increase max speed)

Left Shoulder Button (L1) -> tank turn left

Right Shoulder Button (R1) -> tank turn right

Left Analog Stick -> dynamic steer (point wheels in direction stick points)

Square -> acknowledge faults (if the rover ever stops responding, hit this!)

Left Analog Stick -> control speed of left wheels

Right Analog Stick -> control speed of right wheels

The gamepad_input_drive ROS2 topic publishes the following message type:

Field	Type	Description
x_button	int8	Accelerate forward (Steering schema).
o_button	int8	Accelerate backward (Steering schema).
triangle_button	int8	Toggle between Steering and tank control schemas.
square_button	int8	Acknowledge rover motor faults.
l1_button	int8	Tank turn left (staSteeringndard schema).
r1_button	int8	Tank turn right (Steering schema).
l2_button	int8	Gear down (decrease max speed).
r2_button	int8	Gear up (increase max speed).
select_button	int8	Reserved/unused in current mapping.
start_button	int8	Reserved/unused in current mapping.
home_button	int8	Reserved/unused in current mapping.
l3_button	int8	Left stick click (currently unused).
r3_button	int8	Right stick click (currently unused).
l_stick_x	float32	Direction to point wheels in horizontal axis (Steering schema).
l_stick_y	float32	Direction to point wheels in vertical axis (Steering schema). Speed and direction of left side wheels (Tank Schema)
l_stick_analog	float32	Magnitude of left analog stick movement.
r_stick_x	float32	Right analog stick horizontal axis (currently unused).
r_stick_y	float32	Speed and direction of right side wheels (Tank Schema)
r_stick_analog	float32	Magnitude of right analog stick movement (currently unused).
d_pad_x	float32	Pantilit camera yaw control
d_pad_y	float32	Pantilt camera pitch control

Human drive controls consist of five primary scripts: the two drive-specific ros nodes plus three function library scripts.

Provides functions to translate input into an array of wheel instructions to allow the rover to steer. Wheel_orientation_rotation() takes joystick input and interprets it as an array of angles to pass to the steering motors on the wheels. This is the function that takes the wheels and points them in a new direction. Rover_rotation() takes a button input and provides an array of wheel speeds in the form [top right, top left, bottom left, bottom right]. This is the function that causes the rover to turn tank style. Note that this is a longer function, since the direction the wheels are pointing influences which wheels need to run forward and which need to run backward. Also includes the functions for adjusting the speed based on the analog stick input for tank control.

Provides a speed_controller class that monitors the wheel acceleration and speed for the rover. To tune the rover speed, adjust the attributes assigned in init. Gears provides a list of dictionaries that control the gears the rover locks to. The current (2025-05-31) physical maximum wheel speed is 3200 rpm. Acceleration_rate, as per its name, determines how quickly the rover speeds up. However, do note that this can also be affected by history_size, since that determines the number of previous speeds that are averaged to smooth acceleration. A bigger history size means a lower acceleration rate, regardless of what the acceleration_rate attribute is. Decceleration_rate determines how quickly the rover stops when the user stops acceleration, while downshift_deceleration_rate determines how quickly we slow down when we gear down. Note that to control turning speed, you need to look at drive_control_node.py, not speed_control.py. This file only affects straight-line motion.

This script defines the drive_control_node ROS2 node, which processes gamepad_input_drive messages and converts them into wheel speed and steering angle commands for the rover. It also manages control modes, gear shifting, and fault acknowledgement. It publishes the speeds to the drive_speed_input ros topic and wheel angles to drive_steering_input

Topic Name	Direction	Message Type	Purpose
gamepad_input_drive	Subscribe	msg_srv_interface/msg/GamePadInput	Receives controller input for driving.
drive_speed_input	Publish	std_msgs/msg/Float32MultiArray	Sends wheel speed commands.
drive_steering_input	Publish	std_msgs/msg/Float32MultiArray	Sends wheel orientation (steering angle) commands.
acknowledge_faults	Publish	std_msgs/msg/Bool	Signals fault acknowledgement to stop blocking movement.

This node akes the wheel speeds from the drive_speed_input ROS topic and converts it to instructions the firmware can understand. It calls the functions in driveCANCommunication.py, which send specific messages to the CAN buses. It handles receiving drive commands, broadcasting them over CAN, and collecting motor diagnostics for (Voltage, Current, State, Temperature) for each wheels. Talk to electrical for more details on this.

Topic Name	Direction	Message Type	Purpose
drive_speed_input	Subscribe	std_msgs/msg/Float32MultiArray	Incoming wheel speed commands from drive_control_node.
drive_steering_input	Subscribe	std_msgs/msg/Float32MultiArray	Incoming steering commands from drive_control_node.
acknowledge_faults	Subscribe	std_msgs/msg/Bool	Clears motor faults when True.
drive_motors_info	Publish	msg_srv_interface/msg/DriveMotorDiagnostic	Publishes motor voltage, current, state, temperature.
drive_speeds_info	Publish	std_msgs/msg/Float32MultiArray	Publishes measured motor speeds.

Service Name	Request/Response Type	Purpose
drive_motors_status	msg_srv_interface/srv/DriveMotorStatus	Returns the health status of each drive motor.

This script defines the pantilt ROS2 node, which controls a pan-tilt camera mount and publishes GPS and IMU data from the attached hardware.

Topic Name	Direction	Message Type	Purpose
gamepad_input_drive	Subscribe	msg_srv_interface/msg/GamePadInput	Receive D-pad input for pan/tilt control.
roverGPSData	Publish	std_msgs/msg/Float32MultiArray	Publishes GPS coordinates from the PanTiltGPS hardware as [# of Satellites, Latitude, Longtitude].
roverIMUData	Publish	std_msgs/msg/Float32MultiArray	Publishes IMU sensor readings from the PanTiltGPS hardware.