TEMAS RGB Camera Node

The TEMAS RGB/visible-light camera node streams color frames as ROS2 sensor_msgs/Image, publishes status and info topics, and exposes runtime-tunable camera settings (exposure, brightness, contrast, focus, saturation, gain).

Parameters may be set at startup or changed live using ros2 param set.

class TemasCameraVisNode(*args, **kwargs)

Bases: Node

ROS2 node for streaming a TEMAS RGB camera.

This node connects to a TEMAS VIS camera, continuously publishes frames as ROS2 images, and provides camera status and info topics. Camera parameters (exposure, brightness, contrast, lens position, saturation, gain) can be set at startup or dynamically via ROS2 parameters.

Parameters:

• ip_address (str): IP address of the TEMAS device (default: ‘192.168.4.4’)

  Example:

  ros2 run temas_ros2 camera_vis --ros-args -p ip_address:=192.168.4.4

• set_exposure_time (int): Exposure time in microseconds (default: 17000)

• set_brightness (int): Brightness (default: 50)

• set_contrast (int): Contrast (default: 3)

• set_lens_position (int): Lens focus position (default: 25)

• set_saturation (int): Saturation (default: 3)

• set_gain (float): Gain (default: 2.0)

Dynamic parameter change example:

ros2 param set /temas_camera_vis set_exposure_time 20000

ros2 param set /temas_camera_vis set_brightness 60

Published Topics:

• temas/camera_vis/image_raw (sensor_msgs.msg.Image) – live camera frames

  Example:

  ros2 topic echo /temas/camera_vis/image_raw

• temas/camera_vis/status (std_msgs.msg.Bool) – frame status (True if frame received)

  ros2 topic echo /temas/camera_vis/status

• temas/camera_vis/info (std_msgs.msg.String) – connection info messages

  ros2 topic echo /temas/camera_vis/info

Usage Example:

Start the node with default parameters:

ros2 run temas_ros2 camera_vis

Change camera exposure at runtime:

ros2 param set /temas_camera_vis set_exposure_time 25000

View live images:

ros2 run rqt_image_view rqt_image_view

Then select topic /temas/camera_vis/image_raw.

Notes:

• The node automatically starts a background thread to continuously fetch frames.

• Status topic indicates whether frames are successfully received.

• All camera settings can be updated dynamically via ROS2 parameters.

try_connect()

Attempt to connect to the TEMAS camera.

This method establishes connection, starts the camera streaming thread, and applies the initial camera settings.

apply_camera_settings()

Apply the current parameters to the camera.

Methods from temas.Camera used:

• set_exposure_time(microseconds: 50–33000) -> str: sets exposure

• set_brightness(0–100) -> str: sets brightness

• set_contrast(0–100) -> str: sets contrast

• set_lens_position(0–100) -> str: sets lens position

• set_saturation(0–100) -> str: sets saturation

• set_gain(1.123–16.0) -> str: sets gain

parameter_callback(params)

Handle runtime parameter changes.

Updates camera settings immediately when parameters are changed.

Parameters:

params (list[rclpy.Parameter]) – List of parameters being updated.

Returns:

Result of parameter update

Return type:

SetParametersResult

stream_camera()

Continuously fetch frames from the TEMAS camera and publish them as ROS2 Images.

Also publishes a status boolean indicating frame availability.

destroy_node()

Gracefully stop the camera thread and shut down the node.

main(args=None)

Main function to initialize ROS2 and run the TEMAS Camera Node.

Parameters:

args – Optional command line arguments