How to add button states?

[CarlDegio]

I want to use Omega button states to switch movement boundary. I tried some way but still don't work. I would like to ask if you have a better method.

Attached my attempts:

1. Initially, I want to put button states under current ros2 control framework by treating it as fourth joint. Add a button joint in urdf, and add it in fd_controllers.yaml. Read hardware data in fd_effort_hi.cpp. Publish button joint position in state interface of ee_pose_broadcaster.cpp. However, the problem occured at load joints. [ERROR] joint 'button' don't have effort command. I found changing fd.r2c_hardware.xacro may be helpful. But this could destroy the command dimension so I decide to seek another way. But in the end this might be the way to get close to the truth

2. I design another node to read button data. But the function dhdOpen() seems can't be executed twice.

[mcbed]

Hi @CarlDegio , the cleanest and I think most efficient way of doing so is to set up a GPIO component in ros2_control that will handle the button and add it into the hardware. By doing so you just need to add it to the ros2_control urdf and you can read from it either using the joint_state_broadcaster on the /dynamic_joint_states topic or by creating you dedicated broadcaster.

If you need some help to do it, juste create a PR and I can give you a hand.

[CarlDegio]

Thank you! I just know the GPIO type of ros2_control. I will try it and seek for help if there are problems。

[CarlDegio]

I add GPIO states successfully. But I only have Omega.3 device, which only has one button, so I only add id 0 button in code. My change at: #4

[tpoignonec]

FYI, this code has been added to the main branch (humble), see PR #15.