How to get cliff sensors data using ROS2?

[cloudbuzzer]

Where is /cliff_state topic?

[shamlian]

Where are you finding documentation about this topic? If the robot experiences a cliff, that is exposed in /hazard_detection. I searched the API documentation and I don't see reference to a "/cliff_state" topic.

[cloudbuzzer]

Thanks

[cloudbuzzer]

What about direct wheel drive, is it possible?

[shamlian]

Create 3 does not expose direct PWM access to the wheels. You can command velocities or positions, and the robot will close the loop.

[shamlian]

If you haven't already read this, you might find this helpful: https://github.com/iRobotEducation/irobot_create_msgs

[justinIRBT]

To determine which cliff, see the documentation of this message https://github.com/iRobotEducation/irobot_create_msgs/blob/main/msg/HazardDetection.msg. In the hazard detection vector, each hazard has a type and a header. The header will have the frame id of the hazard that is triggering, so it will tell you which of the 4 cliffs is associated with the triggered hazard.

[justinIRBT]

There is no "/cliff_state" topic on Create 3; to determine which cliff is triggering, see the documentation of the Hazard Detection message. In the hazard detection vector, each hazard has a type and a header. The header will have the frame id of the hazard that is triggering, so it will tell you which of the 4 cliffs is associated with the triggered hazard.